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iFi Audio AMR Audio by thorsten loesch

دوشنبه 25 آوریل 2016
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Retro-Stereo50-01

 

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این آقای thorsten loesch یه طراح باهوش حساب میشه تو این های اند و تو سایت رومی هم ای دی داره و بحث میکنه.

این آدم تو حوزه دیجیتال خیلی کار کرده و مقالاتی داره که خیلی ها از جمله طراح Lampizator هم اونارو خونده و از تجربیات تورستن استفاده کرده.

این طراح تو کلاس قیمتی پایین سیستم های زیر رو ارايه داده که من  iDSD و 3.0 iUSB رو خریدم. یه ست جالب خونگی هم داره که با بلندگوی BBC فروخته میشه. هر کدوم از این کامپوننت ها یه کاری انجام میده.

توضیحات بیشتر تو سایت http://ifi-audio.com/ هست. نماینده این برند هم آرمن هست 09121198262 . قیمت ها بین 300 تا 500 دلار هست.

 

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برند Abis Shuhgetsu Amplification from Japan

یکشنبه 8 می 2011
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http://www.sibatech.co.jp/abis/index.html

http://www.sibatech.co.jp/abis/Shugetsu%20tech%20for%20web.pdf

Idealized In The Digital Realm, Perfected In The Real World

Before we became acquainted with Tetsuo Kawanishi, former associate professor of the University of Electro-Communications Tokyo, we were unaware of the root cause of high frequency transient distortion in circuits employing negative feedback. Mr. Kawanishi’s work has revealed that this peculiar distortion is the result of modulation of high frequencies in circuits using (or misusing) negative feedback. The result of Mr. Kawanishi’s research is Shuhgetsu NRF (Negative Resistance Free) solid-state amplification technology. After extensive listening sessions using Mr. Kawanishi’s prototype amplifiers, and with numerous speaker types, we engaged him to design a completely new preamplifier and power amplifier. These new designs, the C-120 Stereo Preamplifier, and P-1120 Mono Block Power Amplifier, make use of Mr. Kawanishi’s patented circuits and years of research into the behavior of feedback amplifiers.

Good Sound Starts With a Good Circuit

No amount of expensive parts and careful tweaking can overcome the limitations of a poorly designed circuit. When we fully understood Mr. Kawanishi’s identification of the cause of bad sound from misapplied feedback, and his unique approach to perfecting feedback circuits, we knew that his designs would be an ideal platform for state-of-the-art audiophile components. Before talking about special quality parts, and build techniques, we want to share some technical insights about ‘negative resistance’ in a feedback amplifier.

Transient Distortion as caused by Negative Resistance:

What is ‘negative resistance’ and how harmfully is it to reproduced sounds?

Many solid-state amplifiers employ negative feedback to minimize high-frequency distortion. However, standard feedback does not work perfectly resulting in the erratic behavior of input and output impedance. The result is negative resistance. Such design flaws are present in emitter-follower and cathode-follower (as used in Marantz type equalizer) circuits.

Transient distortion may arise once this behavior occurs. Negative resistance tends to oscillate a circuit which destabilizes an amplifier’s operating point, causing the signal to be improperly amplified with transient distortion, which muddies the reproduced sound. When the circuit containing this negative resistance is exposed to high frequency noise (RFI, or switching power supply noises, for example), its operation is further destabilized, increasing transient distortion. In the old days of vacuum tubes, such high frequency noises seldom existed in audio reproduction. And even when the noise did occur, most tube amp designs employed a high frequency roll-off network at the point where the negative feedback was injected. This kept the amplifier from trying to reproduce frequencies outside the capabilities of the output transformer. The downside was “classic tube sound” and poor high frequency response.

But since the invention of semiconductors, the negative resistance issue is exacerbated by the transistor’s mass application in audio designs, and further compounded by the development of digital audio techniques. High frequency noises generated by electronic equipment has dramatically increased since the advent of switching power supplies, increased use of radio waves (cell phones) and the inclusion of digital circuitry in virtually every household device (ovens, toasters, etc..). Further, in negative feedback type amplifiers, high frequency noise will often be modulated by audio signals, causing further signals to be created as the result of the intermodulation of signal, HF noise, and “normal” distortion products (meaning distortion from active and passive parts; parts which deviate from the theoretically perfect device—all deviate from the idealized perfect part).

Measures taken in the Shuhgetsu circuits to cope with negative resistance:

In order to remove negative-resistance generated at the amplifier’s input stage, the designer has employed a patented circuit with carefully calculated values. Furthermore, in the feedback line which returns to the first stage of the amplifier, another patented circuit is inserted with differently calculated values to remove negative-resistance born in output impedance.

Herewith, NRF (negative resistance free) circuits are accomplished wherein the operating point is stabilized. Shuhgetsu amplifiers employ NRF circuits in voltage amplification and current amplification. Also, the regulated power supplies used by Shuhgetsu dramatically decreases transient distortion. The combination of carefully applied negative feedback, with low impedance power supplies allow the Shuhgetsu components to realize the potential of feedback, with none of the audible distortions which have given misapplied negative feedback a bad reputation.

Special attention given to power supplies:

Though an oversimplification, amplifiers modulate a power supply. If a power supply has high impedance at some frequencies, and low impedance at other frequencies, an amplifier might display deviations from a flat frequency response. Even worse, the amplifier may be driven to clipping at one frequency and not at others, and these distortions when added to the music can produce gross harmonic and intermodulation distortion.

Shuhgetsu amplifiers use fully regulated power supplies from the front-end voltage gain stages to the current amplifying output stages. The result is an amplifier with excellent damping, frequency response, and low distortion. No matter how good the signal circuit and parts quality, an amplifier must have an adequate power supply, or else the circuits and parts cannot perform their job.

The musical qualities of a regulated power supply:

* Powerful and tight bass in the P-1120 power amplifier. Thanks to use of regulated power supplies placed in all power amplification stages, which prevent voltage drop at significant power output, bass is clean, articulate and tonal. Unlike many tube amplifiers which have unregulated power supplied and limited reserves of power, there is no artificial warmth, no overhang, and no muddiness.

* Whereas power amplifiers generally use regulated power supplies only in the first voltage amplification stages, the Shuhgetsu P-1120 has stabilized power supplies throughout – all the way through to the power stage – unlike others. This fully regulated power supply is costly, but enriches bass reproduction by preventing voltage drops at high output.

* An ideal power supply has zero source impedance to prevent voltage drops, from DC to ultra high frequencies. The source impedance of the Shuhgetsu P-1120 amplifier is in the order of 0.01 ohm up to around 10KHz, and stays within 0.1 ohm above 10KHz due to special filtering and decoupling capacitors used in the power supply.

* An ideal power supply does not have high frequency noise from the AC line input, or generated by rectifiers. Because of carefully chosen transformers, rectifiers, resistors, and filtering capacitors, high frequency noise is shunted to ground before it can be injected into the signal.

* If the source impedance is high in a preamplifier, the sound becomes less powerful and clear. An ideal power supply should be regulated, having low impedance. So, the Shuhgetsu C-120 preamplifier uses the same principals as the P-1120 power amplifier. The supply for the C-120 preamp is the PS-120, which is housed in a separate chassis. By housing the power supply in a separate chassis, the delicate signals present in a preamplifier are fully protected from the various AC line noises and possible EM radiation from the transformer.

* The P-1120 power amplifier is built with a very large capacity EI core transformer, with excellent electromagnetic and electrostatic shielding to prevent this kind of noise from being radiated into the power amplifying circuits.

After a thoroughly engineered design comes careful tuning

After the design was completed to our satisfaction, it was finally time to do final tuning. Many high-end companies spend enormous amounts of time and energy covering up a bad circuit with good parts. With the Shuhgetsu, the parts are just as good, but happen to be in a superior circuit.

* Superior music reproduction is enhanced by the careful selection of circuit components which are chosen based on electrical characteristics. The electrical performance was scrutinized, and parts were chosen based on how close they came to the ideally perfect part.

* Resistors were chosen based on their linearity versus frequency. In other words, some resistors change value with frequency. The Shuhgetsu uses extremely linear resistors, chiefly from Nikkohm.

* Select power supply smoothing capacitors and low value (small capacitance) capacitors were chosen based a number of criteria, including ESR, frequency linearity, and lack of coloration in reproduced sound. This last judgment was based on listening tests, but was given as much importance as the electrical values. The quality of capacitors employed in the power supply has a major impact on the performance of the music amplifying circuits. As it has been said: garbage in, garbage out. The Shuhgetsu power supplies provide premium quality current to the signal stages. The capacitors employed include film types from Rifa and Rifa type 02 electrolytic smoothing caps.

* The Shuhgetsu products employ EMe (epitaxial mesa) power transistors and low noise SiE (SiEP) small signal transistors. These are ultra high performance transistors, carefully chosen for their high performance, are hand matched for minimum channel to channel variation and maximum reduction of distortion.

* TO-3 metal packaged power transistors were chosen for their minimal mechanical vibration and electromagnetic wave generation properties. This reduces intermodulation distortion (IM). Generally speaking, a power transistor generates imperceptible mechanical vibration by music signals, while also generating electromagnetic waves that vary with the music. This often impacts the input stage and causes intermodulation distortion.

Other Features and Considerations

* Differential Input Balanced Transmission Scheme

Balanced operation and connections are featured in both the C-120 preamplifier and P-1120 power amplifier. The benefits of balanced operation far outweigh the extra cost and difficulty in manufacturing. With common mode noise rejection, and low levels of hum, there are drastic improvements in dynamic scaling, localization, airiness, and spatial perspective. Further, the impact of cable quality is much less when using balanced connections. We do encourage purchasing cabling of impeccable build quality, but you will find less audible variation from brand to brand than when compared to single-ended connections. This is due to common mode noise rejection and the more robust nature of balanced operation. However, to make the most of your Shuhgetsu preamp and power amp, please consider the following:

* Because the wavelength of audio frequencies are sufficiently long compared to the length of wiring used in audio equipment, very little scientific investigation has been expended on the influence of cabling on audio signals. When we consider the influence of high frequency noise on an amplifier, it is quite important to emphasize cable matching in high frequency reproduction between an amplifier’s internal wiring and speaker cables. When there is an impedance mismatch, reflections at cable ends will occur, possibly causing an increase in high frequency noise. Shuhgetsu amplifiers are designed with countermeasures that assume a characteristic impedance of 75 ohms for line cables, and 120 ohms for speaker cables. We recommend use of cables specified by the Shuhgetsu designer.

* The cancellation of noise that is a benefit of balanced connection and operation is virtually impossible with single-ended connections. With single-ended connections, any noise induced through EMI or RFI on the connecting cables becomes part of the musical signal because there is no reference with which to compare the original signal. Only balanced connection can delete the problems of EMI and RFI through common-mode noise rejection.

* Further, it was found that balanced amplifiers heat up and stabilize much quicker than single-ended designs. Kawanishi’s unbalanced amplifiers would require at least 15 minutes of heating and stabilization for best sound. But the balanced versions of Kawanishi’s amplifiers sounded good almost immediately after powering up. In comparison to many power-hungry, single-ended designs, which must be left on for hours to stabilize, the Shuhgetsu won’t waste power or shorten your valuable listening time.

Some say that balanced design is a waste. Some say that it doesn’t sound as good. These opinions are based on poorly designed products. Balanced operation produces dramatic improvements, but requires bulkier and more expensive equipment because of the need to process two independent signals in one chassis. Put simply, a balanced design doubles everything of a single-ended design. It takes two duplicate circuits, working in tandem, to produce one balanced circuit. Other manufacturers of balanced amplifiers, with good specifications on paper only, have chosen to use cheap integrated circuit operational amplifiers for cost and space savings. Generally speaking, an IC op-amp is by nature a very high feedback device, and thus generates negative resistance that will muddy the sound. Understandably, this poor sound quality from cheaply built balanced products has lead listeners to conclude that an unbalanced type is actually better in sound. On the other hand, unbalanced amplification fosters listeners’ belief that the sound is better because there is a constant level of even order distortion, clouding the performance, and making the sound less precise. When they hear a poorly built balanced product that has very low noise and even order distortion, it serves to amplify the relative severity of the negative resistance and high order distortion caused by the IC op-amp, mediocre power supply or bad parts quality. Therefore, the Shuhgetsu products, which eschew the use of such IC op-amps is both theoretically and realistically superior in reproduction of natural sound by common mode noise removal.

Sturdy Housing and Provisions for Electromagnetic Wave

* The P-1120 Power Amplifier uses 5.6mm thick steel sheet for the chassis to secure internal components and suppress mechanical vibration at all points.

* Hospital-grade shielding of power transformer winding gaps, as used in medical equipment, guards against electromagnetic waves and noise which would cause common mode noise in the power supply. Without proper shielding, these spurious noises which occur in all transformers would in injected into the musical signal.

* Circuits and components have been carefully arranged to prevent the interaction of power supply circuits and amplification circuits. In very compact designs, there is coupling from one stage to another, causing IM distortion, spurious noise and instability. Components are arranged in the Shuhgetsu in a way that they aren’t being adversely affected by another component.

*The C-120 Preamplifier and PS-120 Power Supply use 3mm thick steel sheet to support the PC boards with a floating anti-vibration rubber mounting system.

* The separate power supply unit suppresses magnetic flux leakage to the preamplifier circuit.

* The same transformer shielding technology used in the power amplifier is used in the preamplifier power supply.

The fruit of our labors, the unique sound of Shuhgetsu

* Extraordinary amounts of detailed information, and low-level signal resolution, enable you to catch subtle point of sounds and to better appreciate and understand the music.

* No colorations assure you that you are experiencing the original sound from the musical instrument, as intended by the artist (not the equipment manufacturer).

* Highly accurate timbre keeps the relative levels of notes in proper placement, so notes do not improperly pop out of focus to impede upon listener engagement.

* No annoying peaks at high output levels from negative resistance. No aggressive sound or distortion at musical climaxes.

* Precise spatiality allows you to hear instrument placement quite clearly, and hear each instrument reproduced independently.

* Accurate phase produces wider listening area so you can better enjoy music off-axis of your speakers.

* Using regulated power supplies for all stages reproduces low frequencies with exceptional stability and clarity, and allows you to appreciate tonal scales of low-pitch instruments.

* The distinct airiness, openness and sound-staging reproduce the atmosphere of a live performance in your listening room.

* From the sound of a gentle stream, to a powerful ocean wave, Shuhgetsu can deliver massive changes in mood, timbre, scale, loudness, and all the other musical attributes that create the musical experience.

* Because of the low levels of noise and distortion, and highly accurate gain stages, the Shuhgetsu amplifier can, as a matter of course, reproduce acoustic instruments with a great degree of fidelity to overtones and detail. At the same time, any category of music can be enjoyed because of the power reserves and truthful character of Shuhgetsu.

* The bottom line is that by using patented circuits that avoid negative-resistance, power supplies that are quiet and low-impedance, parts that are very linear and noise-free, and chassis that rigidly hold components and circuits in an ideal spatial orientation, the sound is amplified with nothing added or taken away.

Abis Shuhgetsu: The genuine sound of musical instruments with no electronic distortion.

————————————————————————————————————–

Model C-120 Stereo Preamplifier (with PS-120 Power Supply Unit)
Model P-1120 Mono Block Power Amplifier
We were unaware of behaviors of modulated high audio frequency that resulted in uncomfortable transient distortion before we became acquainted with Tetsuo Kawanishi, former associate professor of the University of Electro-Communications Tokyo, and the designer of the Shuhgetsu NRF solid-state amplification technology. After exhaustive auditioning and investigation of Prof. Kawanishiʼs prototype amplifiers with different speakers, we asked him to design a combination of commercial equipment, preamplifier and power amplifier, as we were converted by his patented circuit design.
◎ Sonic Characteristics of Shuhgetsu Amplifiers
○ High-level of information density: Enables you to catch subtle point of sounds.
○ No coloration: Assures you an experience of the original sound from musical instrument.
○ Highly accurate timbral portrayal: The piano, horn, or soprano vocalization likely coming “Shuhgetsu” NRF Solid State Stereo System up at specific musical scales that does not irritate ears.
○ No annoying peaks at high output level: No looming aggressive sound and distortions.
○ Precise spatiality: You can see instrument placement quite clearly, and hear each instrument reproduced independently.
○ Accurate phase: Produces wide listening area so you can well enjoy music at any position off the speakerʼs front.
○ Full stages driven by stabilized power supply: Exceptionally stable reproduction of low frequency range that allows you to appreciate tonal scales of low-pitch instruments.
○ Quite distinct airiness and perspective of acoustic field: Reproduces the atmosphere of live performance in your listening room.
○ Sound unworldly like a limpid stream, and powerful like the ocean wave.
○ Depth of character: A Shuhgetsu Amplifier can as a matter of course reproduce acoustic instruments and any category of music.
◎ Genuine sound of musical instrument with no electronic distortions, employing patent applied circuit that deletes Transient Distortion caused by Negative Resistance.
● Transient Distortion caused by Negative Resistance
What is ‘negative resistance’ and how harmfully is it to reproduced sounds?
Solid-state amplifiers generally adopt ‘feedback’ circuitry to minimize high-frequency distortion, but it usually does not work perfectly resulting in possible degradation of real part
(pure resistance excluding inductance and capacitance) of each input and output impedance (usually complex number) into negative behavior, or negative resistance. Such deficit is
present in emitter-follower and cathode-follower (as used in Marantz type equalizer) circuits.
Transient distortion may arise once Negative Resistance is generated.:
Negative resistance tends to oscillate a circuit which destabilizes an amplifier’s operating point, causing music signal to be improperly amplified with transient distortion, which muddies the reproduced sound.
Infections of external noise:
When the circuit containing this negative resistance is exposed to external high frequency noise, its operation is increasingly destabilized with all the more transient distortion. In the
old days of vacuum tube, such high frequency noises seldom existed in audio reproduction.
But since the invention of semiconductors, the negative resistance issue is exacerbated with the transistorʼs mass application in audio designs, and further compounded with digital
technologies development. Infections of high frequency noises generated by electronic equipment has incomparably increased more than ever. (In a feedback type amplifier, high
frequency noise may also be modulated by audio signals.)
● What measures are taken in the Shuhgetsu amplifiers to cope with negative resistance? (2 patents applied)
In order to remove negative resistance generated in input impedance, the designer added a patented circuit with carefully calculated constant value in the input stage. Furthermore, in
the feedback line which returns to the first stage of the amplifier, another patented circuit is inserted with differently calculated constant value to infinitely remove negative resistance
born in output impedance.
Herewith, NRF (negative resistance free) circuit is accomplished wherein the operating point is stabilized. Shuhgetsu amplifiers employ NRF circuit in voltage amplification, power
amplification and stabilized power supply circuits to dramatically decrease transient distortion.
◎ Super High Fidelity music reproduction by use of carefully selected circuit components which are graded as close as possible to ideal elements.
● Theoretical values of high grade resistors and capacitors used in Shuhgetsu are about the same value in high frequency reproduction as in the following:
○ Resistors with minimum value variation regardless of frequency change.
○ Select electrolytic capacitors and low-capacitance capacitors for free of coloration in reproduced sound.
○ Block type electrolytic capacitors and film capacitors strictly selected for smoothing of ripple current and absorption of rectifying pulses in the power rectification circuit.
○ Adoption of EMe (epitaxial mesa) power transistors and low noise type SiE (SiEP) small signal transistors.
○ TO-3 metal package power transistors for their minimal mechanical vibration and electromagnetic wave generation properties, which reduces cross-modulation distortion.
(Generally, a power transistor generates imperceptible mechanical vibration by music signals, while also generating electromagnetic waves in parallel with the signals. This often impacts
input stage and causes cross-modulation distortion.)
◎ Balanced Connection adopted in both preamplifier C-120 and power amplifier P-1120 with positively deleted in-phase common mode noise and hum noise, for stabilized reproduced sound with drastic improvement in dynamic scaling, localization, airiness, and spatial perspective.
● Cable Matching:
Because the wavelength of audio frequency is sufficiently long compared to the length of wiring used in audio equipment, less attention has been paid to wiring affecting sound quality.
However, it is quite important to emphasize cable matching in high frequency reproduction between an amplifierʼs internal wiring and speaker cables when we consider the influence of
high frequency noise to an amplifier. When matching is not properly taken, reflections at cable ends will occur to cause possible increase of a particular bit of high frequency noise.
Shuhgetsu amplifiers are devised with countermeasures that assumed a characteristic impedance of 75 ohms for line cables and 120 ohms for speaker cable respectively. We
recommend use of cables specified by the Shuhgetsu designer.
● Balanced Connection:
In order to clear up these problems once for all, Shuhgetsu amplifiers employed Differential Input Balanced Transmission Scheme, wherein 3-line information transmission (phase
between hot and cold differs by 180 degrees) with a cold line added to ordinary two-line unbalanced transmission (hot and ground). This method enables cancellation of high
frequency noise riding on a signal line as in-phase element and delete to the utmost limit in order to depress transient distortion as much as possible. This is an effect impossible with
unbalanced system. Further merit is in heat-up time of the amplifier. The designer Kawanishi’s unbalanced type amplifiers used to require at least 15 minutes in heating up, but
balanced type enables quick music-listening right after the power is switched on with ideal sound quality.
● Does balanced connection produce bad sound?:
This balanced connection method produces dramatic improvements but may require more space and make the equipment bulky due to the need to process two independent signals in
one chassis. So some other miniature balanced type amplifiers with perfect specifications have adopted IC operational amplifiers for amplification stage to save space. Generally, an IC
operational amplifier is of high feedback nature and generates negative resistance that may muddy the sound, thus leading listeners to conclude that an unbalanced type is actually
better in sound. On the other hand, unbalanced amplification fosters listeners’ delusions that the sound is better because it becomes only partially aggressive when it comes under the
influence of high frequency noise. Therefore, Shuhgetsu balanced system without the use of such IC operational amplifiers is both theoretically and realistically superior in reproduction of
natural sound by common mode noise removal.
◎ Powerful and Sharp Bass in the P-1120 power amplifier, thanks to use of stabilized power supplies placed in all power amplification stages to prevent voltage drop at significant power output
● Whereas a power amplifier generally employs a stabilized power supply only in the front power amplification stage, Shuhgetsu P-1120 has stabilized power supplies throughout – up
to the power stage, unlike others. This full-stage stabilization is costly but enriches bass reproduction by depressing voltage drop at high output.
● An ideal power supply has zero source impedance to prevent voltage drop from DC to high frequency area, and does not have high frequency noise. Source impedance of Shuhgetsu
amplifier P-1120 is in the order of 0.01 ohm up to around 10KHz, and stays within 0.1 ohm even in higher (than 10KHz) frequency area due to special decoupling capacitors circuit in
the power supply.
● If the source impedance is high in a preamplifier, overall sound becomes less powerful and sharp. An ideal power supply should be a stabilized type having low impedance. So, Shuhgetsu preamplifier C-120 is also designed with this type of supply unit PS-120, which is housed in a separate chassis.
● P-1120 is built with a large capacity EI core transformer with excellent electromagnetic and electrostatic shielding to secure stable and clean power supply.
◎ Sturdy Housing and Provisions for Electromagnetic Wave
● Power Amplifier P-1120:
1) 5.6mm thick steel sheet for chassis to secure internal components and suppress mechanical vibration at all points.
2) Hospital-grade shielding for power transformer winding gaps, as used in medical equipment against electromagnetic wave and static electricity to block off common mode noise in the power supply.
3) Appropriately isolated stage placement to prevent interference between flux leaked from the power supply and electromagnetic wave generated in the amplification circuit.
● Preamplifier C-120 and Power Supply PS-120:
1) 3mm thick steel sheet as strong support structure for PC board unit, with vibration absorption rubber float system.
2) Separate power supply unit to suppress magnetic flux leakage to the preamplifier circuit.
3) Hospital-grade shielding for power transformer winding gaps, as used in medical equipment against electromagnetic wave and static electricity to block off common mode noise in the power supply.
Doc.abis20081218
Additional Technical Description
1. Circuit constant of the Shuhgetsu amplifier was determined not through monitoring scound quality, but by numeric calculation using a computer of a condition wherein negative resistance does no exist after having analyzed input and output impedances modelling on a single stage differential amplification with emitter-follower circuit.
Then the circuit constant is as straightly as possible applied in an actual circuit to determine a final circuit design. Thus, the Shuhgetsu circuitry was determined not by cut and try method but by using the values logically calculated as are. On the other hand, the elements chosen and used by monitoring sound are such parts as resistors and capacitors which are of high grade required to realize the determined circuit design as ideally as possible.
2. Key components used for the Shuhgetsu amplifier are as below:
A) EMe power transistors
B) SE capacitors for compensation
C) RIFA film capacitors as used for coupling or bypassing
D) RIFA Type 02 electrolytic capacitors
E) NIKKOHM plate type resistors
NONE of OFC parts including wires are being used.
3. Points taken care through sound monitoring to select required parts:
A) Much care was taken to enable to hear every note of the piano sound in any scale without deforming the sound image as well as the sound of collision occurring when the piano hammer is percussed. For example, there should not occur abnormal sound of a single note that suddenly brings pressure on the eardrums, and each note in tremolos should be clearly recognized.
B) Lift of soprano or alike vocal in a cetain interval should not abnormally give pressure on the eardrums.
C) Sound image of horn(s) should not deform otherwise distance perspective becomes hard to recognize.
D) The violins in a string concert should not be tightened or get clogged so that sound softness peculiar to strings as often heard in a concert house can be sensed.
E) A single note in piccicato part for contrabass should not unusually hollow in a room, and descending intervals can be clearly caught. (Such low pitched tone instruments as contrabass, bassdrum, timpani, or organ when simultaneously played can be cleanly heard.)
F) Finally, the Shuhgetsu should reproduce a concert hall presence in an audio listening room.
4. Shuhgetsu amplifier does not need a special listening room.
Conventional amplifiers had a problem in transient characteristics, so is much affected by a listening room, where listeners have to care much for curtains, rug or carpet, or other sound absorption material, but Shuhgetsu with super transient characteristics sets you free from sound absorption cares. In any type of room, Shuhgetsu sounds in its own way.
You also do not have to worry about the position to place a speaker system. Even if the speakers are roughly placed, more than a certain level of presence can be obtained. Its practical service area is quite wide allowing a listener with less knowledge about the acoustic field to command the Shuhgetsu. Ideally, the best is to place the speakers facing the front and listen at the vertex of an isosceles triangle. Further, it is suggested to give minimum 1 meter gap between the speakers and the wall behind.
Designer Tetsuo Kawanishi
Jan. 19, 2009
His following patents are employed in the Shuhgetsu:
No. 2118015 Collector type 2 stage feedback amplification (Dec. 6, 1996)
No. 2794667 Negative feedback amplification (June 26, 1998)
About the Output Circuit of P-1120 Power Amplifier
P-1120 output stage is ended with Complementary Parallel Push-Pull circuit. Designer Tetsuo Kawanishi explains why he adopted this circuitry as follows.
“As known widely, a transistor amplifier was born with semi-complementary push-pull circuit. Later a complementary circuit designs were developed little by little, and amplifier manufacturers began employing the complementary circuit except for a part of power IC, and majority of the manufacturers have followed one after another up to the present date.
Recently, production of power transistors suitable for audio use tend to be discontinued, so there are some manufacturers who went back to semi-complementary design. I am using complementary circuit for high end and semi- for less expensive products.
Parallel connection is adopted for the Shuhgetsu P-1120 to achieve high power output successfully without sacrificing audio quality as long as maximum two parallel stages.
This is the best choice to satisfy both of power output and sound quality. Many other manufacturers employ more than four parallels knowing that sound suffer demerits such as blur and lack in delicacy. Therefore, P-1120 can outstrip other higher output power amplifiers with 4 parallels. An example of the reports from my client is that Telos-200 sounds generally inferior to P-1120.”
April 4, 2009
Translation: M. Shibazaki, SIBATECH, Inc.

 

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Goldenote Demidoff Signature

پنجشنبه 23 دسامبر 2010
/ / /

میخواستم این مطلب رو تو انجمن بنویسم چون بنظرم ارزش یک پست تو سایت رو نداشت اما دیدم انجمن پر پر شده و تا درست شدنش زمان لازمه و برای همین این مطلب رو اینجا نوشتم.

یک آمپلی فایر Single Ended Class A ترانزیستوری 50 و 75 واتی که محصول شرکت Goldnote هست. داخل این آمپلی فایر طوری هست که انگار عین AudioNote درست شده و اینطور تو ذهن تداعی میشه که همین آقا پیتر Audionote اونو میسازه.

این شرکت تو رنج قیمتی بین 1000 تا 7000 دلار کار میکنه و به قیمتش صداش می ارزه، چند تا تحلیل رو بخونید :

http://www.positive-feedback.com/Issue36/demidoff.htm

http://www.6moons.com/audioreviews/bluenote/demidoff.html

http://www.avguide.com/review/tested-goldenote-s-1-signature-integrated-amplifier-and-koala-cd-player

The Demidoff Silver Plus is a single ended Multi-Powered transformer stereo integrated amplifier that is handcrafted to ensure the highest performance level.
The Demidoff Silver Plus uses the finest version of the Mirror-Amp™ pre-amp section. Such gain stage is obtained using a proprietary special cascade differential amplifier with a mirror current, ensuring a super-linear signal virtually eliminating distortion. It also deploys a different output design than the other simpler Demidoffs, providing state of the art linearity and improved efficiency.
The power supply is managed by 12 different massive transformers made specifically on custom design. In order to ensure the best sonic performance, there is also an extra dedicated smaller transformer electrically isolated from the other ones that is dedicated to power two separate circuit boards controlling the Vu-Meter fluorescent lights, the motor of the volume control, the internal protection relays and even the power ON led light.
Four custom Golden transformers work as “pure” power energy suppliers while eight are decoupling transformers, mechanically isolated, to filter the DC power entering the preamplifier Mirror-Amp™ section. Such massive inductive power supply guarantees the lowest interferences from AC power.
All the strategic power & audio sections are wired with Rounded Solid Silver bars. The RSS is a 2mm diameter bar made with 92.5% pure silver and 7.5% electrolytic OFC. It provides the very best conductivity available.
The input wires are connected to the customised selector with a 2.5mm silver cable specifically made for this flagship Amplifier.
As per all the Demidoff amplifiers, the Demidoff Silver Plus does not have active nor passive filters on the audio signal. We have designed specific passive thermal switches to turn the amplifier power off completely reaching an internal temperature over 80°Celsius (180°Fahrenheit).
Its chassis is completely made of high mass aluminium to minimize RFI and EMI interference through having a completely non-magnetic paths!
The Demidoff Silver Plus has two high precision Blue Fluorescent Vu-Meters and a remote control for the volume, both powered by a dedicated transformer to avoid any kind of interferences on the signal path that could affect the sound quality.
The Demidoff Silver Plus supports a wide range of inductive and resistance loads so it can be matched with any kind of audio cable, allowing users to employ their favourite wiring combination. The use of customised & the finest electronic components plus a totally new power supply cap section ensure supremely high levels sonic performances.
As all the Demidoff amplifiers the Demidoff Silver Plus is equipped with all custom design connectors.

POWER OUTPUT: 75w+75w @ 20-20.000Hz
THD (Total Harmonic Distortion): 0.2% @ 20Hz – 20KHz
POWER TRANSFORMERS: 4 Audio Power E core customized +8 Decoupling Power supply + 1 controlling Transformers
NOTES: Fluorescent Vu-Meters on power output controlled by a separate transformer – RRS™ (Rectangular Rounded Silver bar) on the audio signal path.

شب جمعه خوش بگذره

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Let Sound be Your Teacher

جمعه 17 سپتامبر 2010
/ / /

این جمله رو تو ابتدای سایت BYOB (به معنی Bring Your Own Battery) میبینید که بنظرم جمله زیبایی هست و همانطور که قبلا گفتم درک Audio یک چیز Subjective هست و تا خود شنونده دنبال شنیدن صدا نباشه هیچ کتاب و نوشته ای به تنهایی نمیتونه بهش کمکی بکنه.

آقای Charles Altmann از آلمان صاحب برند Altmann Micro Machines که درباره خودش چنین نوشته :

Altmann Micro Machines is a german company focusing on the deliberate application of technology with the intent to improve customer’s wellbeing through procreation of uplifting and joyful experience. Specialty audio products and developments with a number of applied patents include the Altmann Superlative 24 bit / 96 kHz Digital to Analog Converter, The AMM – UPCI – Ultra Precision Clock Injector , the AMM JISCO – Jitter Scrambling Decorrelator ? the Altmann SPLIF – Split Feedback – Amplifier Topology , The Altmann Tube-o-Lator lacquer – a coating that makes semiconductors sound tube-like, the Altmann Do-it-Yourself Tonearm, The Altmann BYOB -Bring Your Own Battery- high performance vibrationally optimized audio amplifier and the Altmann Attraction DAC, a new and unique DA converter that can play up to 192kHz audio without oversampling and features extensive jitter filtering with dual VCXO precision PLL, switchable JISCO function, tube-o-lator-treated R2R converter, high-precision I/V conversion, and high power output and a vibrationally optimized desging employing a musical spruce sound-board. The Altmann Attraction DAC is the first DAC worldwide that can play fast sampled audio with zero-oversampling, sample by sample with unrivalled acoustic performance. Altmann Micro Machines was founded in 1994 by Dipl Ing. Charles Altmann.

Other Altmann Sites:

www.jitter.de

www.altmann.haan.de

www.amm.haan.de

ساخته های دست این شخص قیمت خیلی پایینی دارند و میتونه مورد استفاده کسانی باشه که هم صدای خوبی میخواهند و هم هزینه براشون خیلی مهم هست.

سایت زیر رو ببینید که این شخص ساخته هاش رو گذاشته :

http://www.mother-of-tone.com/

فکر کنم این برند رو دوست خوبمون به نام heaven (من اسم دیگری از ایشون ندارم و با همین اسم ایشون کامنت میگذارند) معرفی کردند و من ازشون تشکر میکنم.

دوباره برمیگردم ، الان باید برم …

خب ، این آدم در ابتدای سایتش توضیحی داده که گفته اجازه بدید بجای پذیرفتن هر ایده ای ما ببینیم “تجربه به ما چی میگه” The experiment decides که بنظر من این جمله بسیار بسیار درست و مهم هست.

این نوع نگرش باعث میشه ما از فضای مورونی حاکم بر های فای که بیشتر ساخته پرداخته مجلات و فروشندگان هست دور بشیم و بجای بحث های احمقانه رایج X بهتر از Y هست و … ببینیم تجربه شنیداری چه چیزی رو به ما میگه. اتفاقا رومی هم روی این مساله تاکید زیادی داره و خیلی از نوشته ها و گفته های فضای های فای رو احمقانه میدونه.

آقای Charles Altmann در ابتدای نوشته هاش تاکید میکنه بهتره قبل از آشنا شدن با من اون ایده های قبلی رو که از جاهای دیگه به گوشتون رسیده و مبتنی بر تجربه شنیداری نبوده فراموش کنید، متن زیر رو دقیق بخونید :

Messages and Distortion
Imagine You would govern a large country with millions of people living there.
Then, not only a code of conduct or laws are needed for this country to work, but also messages.
A simple message would be: “It is good to be able to defend our country” or “wash your hands when leaving the bathroom”.
Why do you need messages? Well, messages are a tool to make your people stop thinking on their own and start functioning automatically in the way you intend.
If you – the governor of the country – think, that many people living in your country are somewhat stupid, then you would more likely rely on very simple messages.
For example: “It’s good for the economy and for the wealth of all of us to consume goods” or “Smoking cigarettes is bad for your health” .
And bang, your people are in trouble. This is a contradiction: Its good to consume but its bad to smoke. Distortion is what happens, when two messages are in conflict.
So a third message is needed, an exception, in order to resolve that conflict: “Its good to consume a product but its bad, when the product is a cigarette since it is able to cause illness”
When the message stops working, an exception is needed. Unfortunately life can be complex so a variety of exceptions are formulated:
“Buy a microwave but don’t put your pet in there”
“Enjoy your coffe, but caution, its extremely hot”
“Its great to have a 400hp sportscar, but beware of curves”
“Burgers are bad and salad is good, but salad with fried chicken is bad, it can have more fat than the burger”
“You must have that louder exhaust, but use it on the racetrack only”
Since You are not really the governor of the country (call me if you are), lets change the focus now. You live in the country and are bombarded with messages. The messages have been formulated in order to put you into a sleep-state and make you a functioning consuming entity with the illusion of individuality.
Since no message can work for all given aspects of life, you can indeed call them distortions, or in other words:
Distortion happens, when a simple message fails to fit into your view of the experience – you putting your pet in the microwave and being unsatisfied with the end result . That is Distortion.
Any message can only work for a limited view, and therefore I suggest the following practice:
a) try to identify the messages that reach you from the media (news, ads) and other persons.
b) find the messages that are triggered in your mind by any situation.
c) forget them all, its time to wake up.

Messages in Audio
There are many messages in the audio field. And many of them unquestioned, like the stuff you have put so much effort into learning in school or university.
These messages have been forwarded by the audio media, manufacturers and individuals.
Let’s take a brief look at the message salad:
“It must have flat frequency response”
“The harmonic distortion must be as low as possible”
1000 Watts is better than 100 Watts is better than 50W is better than 10W is better than 3 Watts
“The step response of the speaker don’t look good on the diagram”
The cone must be made of a stiff material
“SACD is better than DVD-A is better than CD, but Vinyl is best ”
Those messages have put you to sleep, so that you can simply sleep-walk into the next store and buy the stuff with the largest numbers: “I’m going to spend 10.000 bucks and I want 1000 Watts, 100 pounds, most zero’s on the distortion figure and the damn-highest sampling frequency you stock, sucker ! ”
You have already done that and it didn’t work out soundwise? You have followed all of the currently popular audio messages, and what you get is: Distortion.
Well, what do You think why You finally stranded here ?
So before continuing with this funny BYOB site, please forget all messages, at least those audio messages, so you don’t have to ask yourself (or me) boring questions concerning frequency-plots (yes, its flat) etc. (However, I am always thankful for interesting questions or remarks.)
But, as this site also contains messages – what else -, I would like to stress the point, that I don’t want you to unconditionally believe my stuff, I just want you to contemplate about it unprejudiced and awake.
The experiment decides

مطالب جالب دیگری هم خصوصا در مورد لرزش تو سایت ایشون هست :

http://www.mother-of-tone.com/listen.htm

http://www.mother-of-tone.com/vibration.htm

http://www.mother-of-tone.com/mother.htm

http://www.mother-of-tone.com/lacquer.htm

http://www.mother-of-tone.com/current.htm (این لینک خیلی جالب در مورد برق سیستم گفته حتما بخونیدش)

تو آخرین لینک بالا در مورد Power Supply اینطور میگه :

What makes a high-quality audio amplifier expensive ? It is the power supply

قبلا هم گقتم Solidstate های خوب مثل ASR و Vitus همشون تو طراحی Power Supply با بقیه فرق دارند. این آقا استفاده از باتری رو پیشنهاد میکنه کاری که ASR انجام داده و میدونید چقدر هم رومی روی مساله برق وقت گذاشته.

این آدم یک آمپلی فایر ساخته (شکل بالا رو ببینید) که با برق باطری اتوموبیل کار میکنه و 10 وات به 8 اهم میده که نیاز به بلندگوی با حساسیت بالا داره و کل قیمت درخواستیش 950 یورو هست.

دو مطلب هم در مورد فرمت دیجیتال نوشته که خیلی جالبه :

http://www.mother-of-tone.com/cd.htm
http://www.mother-of-tone.com/timeband.htm

http://www.jitter.de/

حتما حتما دو لینک بالا رو بخونید. برخی شرکتها مثل EMM Labs بیشتر روی پاسخ پله تاکید دارند و برخی روی پاسخ فرکانس که این ادم میگه اگر رفتید به سمت بهتر کردن پاسخ فرکانس باید پاسخ پله رو هم بهینه نگه دارید.

و این آقا یک DAC خیلی خوب با قیمت 950 یورو ساخته که تو شکل زیر میبینیدش :

و اینکه ایشون فونو استیج هم ساختند.

ببینید در مورد ساخت بلندگو و انتخاب درایور چه حرف های جالبی زدند :

About Speaker Drivers

As I stated in earlier chapters, a good sound will be always present, when distortion mechanisms are absent.

The same holds true for speakers.

Unfortunately I have the feeling, that today’s designers of speaker drivers seem to have absolutely no idea, what they are doing.

In the early days, a speaker manufacturer or designer listened to his products and if it did not sound good, it was certainly regarded as wrong. Today they rely on measurements in anechoic chambers and many of them respect their own listening less than their futile measurements.

Also the technical specification of speaker drivers gives you lots of useless numbers, but not any information of the most important construction features.

In fact, there are only two real distortion mechanisms concerning speakers, but you will not be able to find any contemporary speaker driver, which is designed in order to avoid those simple distortion mechanisms (there are very rare exceptions).

1) Wrong materials

The speaker cone and coil-former material is much more important to the sound than the geometry and basket of the speaker. The Mother-of-Tone material for cones and coil formers is PAPER.

It is nothing short of ridiculous to make a speaker with an aluminium or titanium, polypropylene or ceramic cone. It doesn’t work. Well, some think it does 😉

The only thing unsuited cone materials can do is to nerve you. Speakers that employ those unsuited materials must have very complex crossover networks in order to keep you from continued vomiting.

Note: On HF compression drivers, aluminium and titanium diaphragms can still sound good, when the horn is made of a decent material, as sound is reflected inside the horn many times and adapts the vibrational character of the horn-material -> see Mother-of-Tone chapter.

You are still able to get speaker drivers with non-plasticized paper cones, but most of them will have a voice-coil made of aluminium or plastic (i.e. Kapton). Aluminium and Kapton are very good for heat dissipation and you can make cheap hi-wattage speakers with those materials, but what’s the need of hi-wattage, if you can’t bear to listen to the shit?

Above is a view inside a aluminium voice-coil former of a otherwise excellent speaker construction. Although capable of high power dissipation, a speaker employing an aluminium voice-coil former will always sound like sheet metal, which can be useful if you will be using it exclusively for steel-guitar 😉

See above a Kapton voice coil former. Better than aluminium, but never natural sounding. Actually it sounds as it looks… like plastic.

A Nomex voice-coil former (above) yields a high level of sound quality plus a much higher heat dissipation compared to paper. For many speaker applications Nomex is the ideal voice-coil matierial (especially for bass or mid drivers). Unfortunately it is rarely used today (except for some famous Celestion guitar speakers).

When it comes to highest sound quality (and lowest power dissipation) paper is the way to go. See below the cone and voice-coil former of a perfectly constructed 1950’s radio speaker.

Other speaker drivers that still employ paper cones AND paper voice-coil formers are Lowther (beware of hi-ferric ;-), Fostex FE series and some cheap chinese speakers (see below).

The drivers above feature small paper-voice-coils, paper cones, re-fitted foam surrounds, spruce-phase-plugs, small magnet and small power-dissipation. As they have no distortion-mechanism, they are used without crossover. The paper HF driver at the top is fed through a capacitor.

2) Cavities

The second distortion mechanism for speaker drivers is the presence of cavities.

Cavities create resonances and can totally mess up the performance of otherwise decently made speaker drivers.

See the below illustration of cavities (blue) that can be found in a contemporary speaker:

The very majority of today’s speakers use ferrite magnets that leave a relatively large hollow space between the pole piece and the magnet. As each enclosure or cavity has resonant modes, a cavity behind the voice coil (in the magnet structure) will create a distortion. The character of this distortion is a trashy peaky metal sound. This distortion speaks through the voice-coil and is easily identified, as it results in peaks in the frequency response.

Drivers using Alnico and Neodynium magnets typically have no or very small cavities in the magnet structure -> see below a positive example of how a magnet structure should look:

There’s another cavity in front of the voice-coil between the pole-piece and the dust-cap. This is also an enclosure which will generate a resonance frequency peak in the speaker response. It will also prevent accurate signal reproduction of the speaker. The character of this distortion depends largely on the size of the dustcap (the smaller the better) and the voice-coil-former material. A dustcap will in any case fuzz the sound. It will prevent a otherwise focused clean sound production.

If the cavities are so small that their resonance frequencies are above 20kHz, the problem is gone to a large degree. A phase plug (preferrably lacquered wood) is a simple and effective measure to eliminate the front cavity as shown below with a modified Fostex FE164.

If dust protection is needed, this can be accomplished with a sound-permeable material (i.e. textile gauze) as found still today i.e. on the Celestion Vintage 30 and Greenback guitar speakers (guess why).

So let’s summarize:

Any speaker that prevents cavities in front or behind the voice coil and employs paper for the cone AND the voice-coil-former will sound good. ANY SPEAKER!

That was all.

Is it really so EASY to make a great sounding speaker? Yes

A perfect Speaker Driver

A perfect speaker driver employs a non-plasticized paper cone, and a paper or nomex voice-coil former. It uses any kind of magnet, provided that there is no cavity in the magnet structure.

A perfect speaker driver also has no dust-cap, but a phase plug (preferably made of wood), that fills the voice-coil cavity. If a dust-prevention is needed, a sound-permeable material should to be chosen in combination with a short phase plug.

See below, the corrected speaker construction, which avoids cavities:

The suspension and voice-coil diameter is chosen with respect to the desired frequency response.

A speaker as described above, is not necessarily expensive to manufacture, and it also needs no elaborate crossover network, as distortion-mechanisms have been avoided.

ایشون یک بلندگو هم ساختند به ادرس http://www.mother-of-tone.com/speakersystem.htm و به قیمت مناسب 2000 یورو که امکان ساخت توسط خریدار (DIY) هم فراهم هست.

این آدم ایده جالبی هم تو ساخت پنل آکوستیکی داره که بران خیلی تازگی داشت :

http://www.mother-of-tone.com/acoustic_panel.htm

این پنل ها حالت رفلکتور دارند (برخلاف همه که یا جاذبند و یا دیفیوزر!!!!!!) که از چوب ساخته میشوند.

دیگه نگید اکبری برند ارزون معرفی نمیکنه و بهتره برید سراغ فروشنده ها و ازشون بخواهید بجای وارد کردن برندهای درپیت این برند ها رو وارد کنند 😉

یک خبر بی ربط بدم اونم اینکه Luxman چیزهای خوبی داره میسازه (البته نه به خوبی ویتوس و ASR) و من به کسانی که از آکوفیض خوششون میاد پیشنهاد میکنم سری به Luxman بزنند چون الان این برند ژاپنی چیزهای خوبی مثل M-800A ساخته که یاد اون آکوفیض قدیمی ها رو زنده میکنه.

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Lampizator DAC

پنجشنبه 26 آگوست 2010
/ / /

برند Lampizator برند جالبیه، اگر دقت کرده باشید من برندهایی رو دوست دارم معرفی کنم که طراح اونها مانند Decware تو سایتش مطالب بدربخوری رو نوشته باشه و علت علاقه من به AudioPax یا Audio Note و یا خیلی از برندهای دیگه ای که دوست دارم فقط صدای اونها نیست بلکه گفتگوی مبتنی بر تجربه شنیداری اونهاست. البته رومی معتقده روی نگاه و تجربه شنیداری یک طراح یا مودیفایر مثل آقای Lampizator خیلی نمیشه حساب کرد اما من جدا از این موضوع اطلاعات جالبی رو تو سایت این آدم دیدم و فکر میکنم برای شما هم جالب خواهد بود.

بحث در مورد طراح این شرکت قبلا تو انجمن من توسط آقای نوید مطرح شد ببینید :

http://forum.hifi.ir/viewtopic.php?f=55&t=139&st=0&sk=t&sd=a&hilit=Lampizator

آقای Lukasz Fikus طراح لهستانی Lampizator سایت خیلی جالبی داره و مطالب خوبی در مورد تست صدای انواع سی دی پلیرها داره که نشون میده این آدم خیلی از برندهای گران و ارزان رو شنیده ، مودیفایشون کرده و خلاصه اطلاعات جالبی رو از هر کدوم اونها تو سایتش گذاشته که هم برای من جالبه و هم برای کسانی که دوست دارند بیشتر از طراحی داخلی پلیرها بدونند.

این آدم خیلی به آقای Peter Quvortrup (راستی یادتون باشه آقا پیتر اهل کشور دانمارک هستند اما انگلستان زندگی میکنند)  طراح  Audio Note UK احترام میگذاره و در مورد خودش تو سایتش اینطور گفته :

This private site LAMPIZATOR is dedicated to tube DIY, music, and practical ways to best sound reproduction.
More specifically: my goal is to own “the best stereo system in the World” and to do it on a reasonable budget. The second aim is to share with others what I have found out in the process, i.e the Lampizator, The Saba speakers, the gem DAC’s and Russian supertubes.
Since I can’t afford a dream system, I decided to learn what makes this technology “tick” and to build the system myself. Soon the pursuit of hi-fi truth became my passion and I relentlessly look inside the boxes, in vain hope to find honestly made and good sounding products. When I discover something worth noticing, I publish it here. I am sure there are ways of owning an absolutely fabulous hi-fi system which everybody can afford. To put things into perspective, I build for myself systems costing circa 1500 Euro, which beat sonically everything I heard before at cost-no-object demo’s in Frankfurt HighEnd show. If we can buy it – thats fine. If we can’t – we must do it with our own hands. It is a combination of buying used gear on ebay, modifying, mixing and matching, and having open ears to new gems from China.  In fact – it is easy. I think I have found all elements I need: best source – CD player with Lampizator, best amplifiers (tubed of course) , and best speakers (alnico). In my subjective opinion my current system can easily be called one of the best stereo systems in the World. This page is about sharing with others my experience acquired in the process.
I am trying to condemn marketing and engineering B/S which I find inside gear. I am a self proclaimed Prometheus. I steal the industry secrets and give them back to the people. I ridicule the ridiculous. I also easily offend the easily offendable.
Of course you can go out and buy yourself such quality in the shop, in this case the price tag may reach approx. 20 000 -40 000 Euro, so anyone not needing such money is more than welcome to go and spend it. And after you buy it, I challenge you to meet me and compare. I will bring gear costing 1000 Euro and I will win.
My approach is to achieve best sound regardless of the cost, but fortunately my discovery is that it is not the money that make the sound, but intelligent choices.  This page is not a “poor man’s Hi-Fi”, it is about best hi-fi period.

———————————————————————————————————————–

Executive brief: in this private website I summarized my 20 years of experience in designing, building and modyfying the stereo hi-fi equipment. Oryginally inspired by Audio-Note’ Peter Quvortrup philosophy of constant upgrading by better parts, I started a new era in my audio hobby – DIY. Then encouraged by Thorsten Loesch page I started learning about all things related to digital. In the countless articles  I try to share with others the various projects which I tried myself. I minimize the voo-doo talking, and try to ridicule the myths. As diplomma engineer I demistyfy many marketing fairy tales and I try to reward honest companies with my aplause. I do not differenciate between 100 USD dac from Hong Kong, or a 20 years old Philips for 20 Euro on ebay, a grandfathers’ SABA radio or Mark Levinson, Linn, Mc. Intosh or Wadia products. They all can be equally good or equally bad.
I deal with simple improvements, modifications, tweaks, very heavy surgery – all kinds of things you can do to improve your stereo. I also deal with buying HIFI online from Hong-Kong and China. There is a little bit about restoration of old gear, about room accoustics, and about listening enjoyment. Psychoaccoustics, soldering technique, measurements and component matching sometimes also appear in my pages.
You can find many confronting opinions, because what I deeply believed 20 years ago (that Scanspeak is the only good loudspeaker out there) is not necessarily my belief today. So in the form of BLOG rather than a finite webpage – I applaud many products like CD Player Grundig or ribbon tweeter Raven 2 to be World’s best. After some time, thanks to my relentless pursuit for truth – I discover new kings and report that finding to you. So don’t blame me for changing kings and queens every quarter or so. That is the very nature of the search. And by the way, the chase is better than the catch.

I devote great deal of time to tube technology, tubes in general and the circuits. I try many different Telefunken. Siemens, Amperex, Philips, Kenrad, Brimar and Sylvania tubes and I compare them to Russian military ones which I love. But of course YMMV.

Finally, I talk a lot about the tube output stage – the Lampizator. I think it is great. After 5 years of research on over 200 CD players I arrived at a conclusion that NOTHING beats properly made Lampizator stage, and  I described a couple of Lampizator variants with more than 20 different tubes.
I published a short summary of this experience in my DOC called LAMPIZATOR 2.0 which was released in july 2008.

خیلی خوب میشه این برند بیاد ایران و ما ببینیم تو سورس های زیر 3000 هزار دلار چه پاسخی به ما میده. گزارشات زیر رو ببینید :

Vincent
TDA1541A chip (جالبه)
Theta
MHZS
Digilampizator
Goldmund (شاشید به این برند سوئیسی)
Shanling ()
Teac VRDS
Lampucera
Capacitors (اطلاعات جالبی در مورد خازنها)

بخش تازه ها اینجاست : http://www.lampizator.eu/Updates.html

تو بخش تازه ها مطالب زیادی برای خوندن وجود داره مثل:

http://lampizator.eu/LAMPIZATOR/photogallery/STEPS/Lampizator.doc

که مرحله به مرحله مودیفای رو توضیح داده و یا رنکینگ سورس ها در:

http://lampizator.eu/LAMPIZATOR/CD_player_ranking.html.

چیزهایی هم در مورد ساخت بلندگو اینجا نوشته:

http://lampizator.eu/SPEAKERS/PROJECTS/P24/P24_monster_speakers_raal_altec_lansing.html

و لیستی از سورس های ارزان :

0.  Sony XA5ES
1. ARCAM CD73 (Wolfson based, price circa 400 GBP on ebay) (and all other Arcams with Wolfson) Also new WM8741 based Arcam CD17 – yummy !
2. Nakamichi CDP-2E with TDA1541A, Sony CDP557ESD with BB PCM64 DAC
3. Philips 753 and 751 with Philips TDA1549 DAC (and Marantz cd5000 and CD48)
Luxman D-103u
4. Sony CDP-555ESD with TDA1541, Kenwood DP8010 with PCM58P, Sony CDP338ESD with BB-PCM58P DAC
5. Cambridge Audio CD3, CD2
6, JVC 1050Z with K2 filter and JVC DAC
7. Maxi Lampucera with CS4397 DAC from Cirrus (needs transport)
8. SATCH DAC with the TDA1541AS2 (needs transport) now it even comes with factory installed lampizator
9. Cambridge AZUR 540-640 with Wolfson DAC
10. Copland CDP 289
11. Zhalou DAC 2,5 MK2 and 3,0 (needs transport) based on CS4397 and 98
11.B) LITE DAC-AH with 8 x TDA1543 DAC
12. ZERO DAC with AD1852 DAC chip
13.  Bang and Olufsen CD5500 (TDA1541a)
14.  MHZS 66 and 88 (Yes, they sound quite nice ) based on Burr-Brown 1742 DAC
15. Creek CD60
16  AMC CD9
17. Pioneer PD-S06
18. Kenwood DP8010
19. Philips CD 930 and CD 940 which is the same

and of course – all Audio Note DACs (not players) – they are on position ZERO above all players listed.

اینجا هم در مورد عشق بنده Audio Note DAC 4 نوشته که جالبه اگر ترنسپورت CEC رو با DAC آئودیونت جمع کنیم چون اینجور که بوش میاد آئودیو نت خیلی ترنسپورت ساز نیست. میگه :

The power transformers are all EI (Audio Note hates toroids)

مقایسه ترنسپورت ها رو اینجا ببینید که CEC هم تو شون هست :

http://www.lampizator.eu/LAMPIZATOR/TRANSPORT/Transportbattle.html

در مورد آمپلی فایر هم چیزهای جالبی نوشته :

http://www.lampizator.eu/AMPLIFIERS/AMPS.html

1. In pentode tube amps ALLWAYS make a triode mode conversion (unless there is a switch to change the modes). This applies to ultralinear circuits etc.
Triode mode pentodes sound great, but in pentode mode – they sound really BAD. Bad bad bad. The mod is easy and costs nothing.

2. In the input section – remove and short all series resistors – we don’t need any of them. Tubes are happy when coupled to each other directly.

3. sometimes there is too many paralell resistors which form – together with series resistors – some signal attenuators. Get rid of all of them except the resistor which goes from tube grid to ground. Every small tube needs grid grounding resistor, value between 200K to 1 M.
The first input tube may use the volume pot as a resistor – so the paralell R can go out.

4. I like triodes without the cathode capacitor. Most amps use an electrolytic cap across the cathode resistor. Remove it and maybe you can decrease the cathode resistor by half. This sounds much cleaner.

5. Coupling caps: all tubes connect to the next tube by a series cap. Use sizes like 0,47 uF or more in the first stage, and over 1 uF in driver stage. use the RADIAL wound, round type not the box type and not the oval. Radial is the way to wind a good cap.
The best type is paper in oil (PIO) type, copper foil is the best electrode material. (jensen or audionote) or any decent MKP.

6. I routinely remove the global feedback loop and never I found it to be a problem. Without feedback EVERY amp that I know – performed better – more open, louder, with deeper bass, more magic, more what I like.

Thats basically all we need to do. The improvement depends on the circuit but usually the mods open up the sound a great deal. Triode mode is most important of them all. Theoretically we “loose power” but subjectively the sound is louder, more spacious and free. Wery well worth doing.

اینم بهترین هایی که این آدم شنیده از نگاه خودش :

# Best speakers I ever heard:
Audio Artistry Grand Beethoven. (I will never forget the demonstration). That memory lead me to creation of P12 the best of the best projects of my life)
# and — My own P-12 INNERLIGHT- Alnico open baffle.
# Worst audio system:
the award for worst sound at Frankfurt 1995, 1996, 1997 and 1999 goes to full Naim system. Demonstrated by NAIM, so cant blame the set-up or component matching. Everything that I hate about reproduction, in one ugly package.
# Best Audio sound: at Frankfurt 1995, 1996, 1997 and 1999 goes to STAX Omega headphone system.
# Worst demonstration of well regarded audio system in the history: Grande Utopia speakers driven by Carin monos at Warsaw Holiday Inn.
# Best cables regardless of the price:
IC: Audio Note AN-VZ
Loudspeaker: Audio Note AN-SPZ in biwiring mode.
# Best budget IC: Goertz Sapphire , Nordost Blue Heaven
Best small loudspeaker without bass: Sonus Faber Guarnieri Homage.
# Best CD transport: Audiomeca Mephisto with Audio Note AN-Vx analogue cable as digital.
# Best CD player: Tube Technology Fulcrum. Best economy player: Copland 289
# Best small signal tube: 6H2P (for 6922 circuits it is a revelation). In every application it is a revelation. Head and shoulders above other, not counting real exotica NOS. MUCH better than the 6H30P so called supertube by mr. Khomenko.
# Best Amplifier regardless of price: Audio Note Ongaku. No comments.
# Best capacitors for de-coupling:  Audio-Note copper foil paper in oil, and same goes for the tweeter cap. But beware: they tend to BREAK short very easily for no reason at all.
# Best solid state amplifier: TACT Millennium Mk2.
# Best recorded CD for testing of the equipment:  Shirley Horn – “Remembering Miles”. Patricia Barber: “Modern Cool”
# Best vinyl playback: Clearaudio deck and cartridge.
# Best power tools for woodworking: Kress
# Best DAC chip – Philips TDA1541aS2

برندهایی که از نظر ایشون پدرسوخته نیستند اینجاست :

http://www.lampizator.eu/Thegoodthebadandtheugly.html

SONY
Audio-Note
Twisted Pear (Russ Audio)
Copland
Cambridge
Saba (till 1970’s)
Arcam
Meridian
Grundig till 1990
DUAL
Philips
Yamaha
NAIM
Audio Alchemy
Tube Technology
TEAC
Kenwood
BAT
VAC
PS Audio
Audiomeca
Revox
Creek
Marków
AMC

نگاهش به فیلتر برق هم جالبه :

http://www.lampizator.eu/AC%20FILTER/SILK/FILTER.HTML

میگه :

http://www.lampizator.eu/NIRVANA/nirvana.html

So what do I mean by the state of audio Nirvana?

Let me list some very basic conditions:
1. The music in our room sounds drop dead gorgeous
2. five seconds after closing of our eyes and listening we can visualize all musicians and their instruments. We can follow each instrument and each thread easily and we can enjoy the piece as a whole
3. We do not have absolutely any clue that we listen to stereo not musicians (with eyes closed)
4. When the music is touchy we get goose bumps
5. When we listen to good albums we continue all the way to the end and we finish with an eargasm
6. We have zero itch to tweak, sell, buy or upgrade. System becomes unimportant and invisible
7. 10 out of 10 visitors, be it audiophiles or regulars, comment that they never heard better music reproduction
8. The illusion of  “they are here” or better “I am there” is so real it is truly scary. The room in our brain is totally replaced by the perception of the recorded event.
9. The music sounds fantastic at REALISTIC levels that means at the sound level similar to the loudness at the original event (usually this means bloody LOUD)
10.  I cant think of point number ten just for the sake of having a nice round list of 10.

How not to get to audio Nirvana

1. Read all audio magazines. Especially cut through the writing straight to the verdict.
2. Pay attention to 5 star products only.
3. Invest in shakti stones, spiked cones, snake oil, CD demagnetizers, anti vibration platforms, cables that contain silver and gold,
4. Pay attention to CD players which have lowest THD (total harmonic distortion) and amplifiers which have highest damping factor above 1000
5. Regularly visit your friendly dealer and without any strings attached let him get you hooked on the latest Stereophile Recommended Levinson 959.05 for 33 000 USD like a bargain
6. Fill your room with bass traps, diffusers, and sound lenses
7. Move to the basement and build a dedicated room isolated from family, friends, relatives and fresh air.
8. Go to every audio show you can
9. replace all capacitors with Black Gates and all resistors with Vishays and all diodes with Hexfreds IMMEDIATELY.
10. Play the pink noise at max volume and leave the system on repeat for one week.
11. Buy a 10 KWatt pure sinus replicator generator and feed your system with proper AC, and immediately  the music will just sound heavenly … dead. The master guru in the magazine said that the AC is really out of shape these days and that it is REALLY bad for the system.

خیلی نوشته بالا باحاله

ببینید سورس شما از چه چیپی استفاده میکنه :

http://www.vasiltech.nm.ru/files/cd-players/CD-Player-DAC-Transport.htm

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معرفی برند با قیمت های مناسب

یکشنبه 22 آگوست 2010
/ / /

واقعیت اینه من دوست داشتم یک سری برند خوب تو کلاس قیمتی Cost no Object مثل ویتوس و ASR و مارتن و ESP Loudspeaker و جورما به ایران بیاد که بیشترشون اومده و مارتن هم طبق اعلان آقای رحمانی دیگه همین روزها باید پیداش بشه .

فقط بلندگوی ESP Loudspeaker و کابل جورما مونده که فکر میکنم مانعی نیست و فقط کمی زمان لازم داره تا اونها هم وارد ایران بشه (مخلص آقای ابوعلی هستیم 😉 ) و در مورد سورس و بقیه چیزها هم کم کم اتفاقاتی خواهد افتاد. چیزی که فکر میکنم برام جالبه الانا کمی روش وقت بگذارم برندهای خوب ارزان هست.

من این برندهای خوب و ارزان رو که میشه تو قیمت های خیلی پایین ازشون صدای خوبی شنید رو معرفی میکنم و هر وارد کننده ای خواست میتونه اونها رو وارد کنه و خودم هم سعی ام بر اینه آقای رحمانی رو راضی کنم که برخی از اونها رو وارد ایران کنند.

یک دسته بندی جدید هم بنام Affordable Audio اضافه کردم که این نوع مطالب رو تو این دسته بندی مینویسم. حتما مطالب مجله Affordable Audio رو دنبال کنید که اونم چیزهای جالبی رو معرفی کرده.

اینجا رو ببینید :

http://www.affordableaudio.org/aa2010-08.pdf

معتقدم اگر کسی صدا گرفتن بلد باشه میتونه از برندهای خوب و ارزان هم صدای بسیار خوبی بگیره و قیمت های بالا هم سرجای خودشون هستند و من تابحال سعی ام بر این بوده تو هر کلاس قیمتی یک چیز خوب رو معرفی کنم.

باید این بازار تغییر کنه و امیدوارم این اتفاق بیفته.

اولین برند رو من LAMPIZATOR انتخاب کردم (اونم به پیشنهاد TwoGoodEars) به آدرس زیر :

http://www.lampizator.eu/

این برند DAC میسازه و قیمت های خیلی مناسبی رو برای کامپوننت هاش در نظر گرفته و حتی برای علاقه مندان کیت هایی رو هم آماده کرده که هر کسی دوست داشت میتونه خودش اونها رو سرهم کنه.

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