Concert Fidelity Electronics from Japan: A slice of audiophile heaven!

[Steve Hoffman]

I was made aware of the fine amplifiers and line stage made by Japan's Concert Fidelity Electronics when I stumbled in the ESP/Concert Fidelity room at the Denver Hi-Fi show two years ago. I was about to give a lecture on Mastering downstairs and I wanted to check the music samples I had and the room sounded nice from the hallway. I met Mike (and Sean of ESP) and listened to a little Ella Fitzgerald on the equipment and liked it... After the show was over I chatted a lot with Mike Verretto who is the champion of both ESP speakers and Concert Fidelity gear in the United States and we agreed that after CES I would start using this equipment in my listening setup at the house.

Nothing prepared me for the joy that this gear would give me in a true home setting (mine). So last year after CES, Mike Verretto, as promised, delivered to me the actual prototypes of the two 6B4G monoblocks and CF-040 line stage which I immediately started using with my big new ESP Concert Grand II speakers. This year after CES I was lucky enough to receive the pretty pair of actual production amps pictured below and the matching linestage for my new listening room using the dedicated Concert Fidelity interconnects and speaker wire with a pair of ESP Bodhran speakers. Beautiful sound and when the sunlight shines in the room on those red lacquered amplifiers....."Wow" is all I can say. The sound is very musical with a wonderful lifelike palpability, amazing accurate bass response and none of the fake tube "warmth" that other designs sometimes fall back on.

The electronics were set up in my room by none other than Tsuda-san himself, beautiful wife in tow, along with Mike Verretto who set up my ESP Bodhran speakers at the same time. Since Tsuda has no English it was up to Mike (who speaks Japanese like a native) to explain to me some of Tsuda's design philosophy which I have reproduced below.

I chronicled some of this in this old thread:

http://www.stevehoffman.tv/forums/sh...highlight=wife

Having Tsuda-san set up his electronics in my house, well, that was personal service to the max and I haven't touched a thing in that room since; perfect placement and wonderful sound. It was at that time that I asked Tsuda if he would permit me to keep his amp and linestage prototypes to use in my mastering room along with my Venture C-8 speakers. He said I could and I'm honored to have two complete Concert Fidelity systems working in my house. Literally a house full of beautiful sound.


The amps and linestage truly shine with all types of speakers it seems (at least the seven pairs I've tried on them so far): ESP Bodhran, Tannoy Windsor, Tetra 506, Venture C-8, Legacy Victoria, Whatmough 202 Leadlines, Penaudio Serenade. I doubt there would be a listener anywhere on the planet who would NOT love the sound of those monoblock amplifiers and that magical linestage.

I can recommend them with total confidence to anyone who strives for the best sound possible. In terms of lifelike sound, the best dynamics, the best soundstaging, the best side to side imaging, the best tonality and the best all-around pleasing vibe, the 6B4G monoblocks and the CF-040 linestage are true contenders. The linestage also gets BIG marks from me for being able to flavor the final sound by tube rolling. That final touch that means so much.

Masataka Tsuda, the designer and builder of these amplifiers and line stage (and their wonderful dedicated bi-wire speaker cable and RCA interconnects) has an interesting story which I will reproduce below. First I want you to take a gander at this beautiful tube gear. These are the 6B4G Fusion Monoblock Power Amplifiers with an amazing 60 watts a channel, hand built in Japan by Tsuda-san...Price: $28,000 per pair; amplifiers for a life time of enjoyment. According to the designer:

6B4G Fusion Monoblock Power Amplifier

Our characteristic simplified and optimized circuits are combined with extremely high-performance proprietary hand-wound driver and output transformers to deliver the highest quality output from pure direct-heated triodes. The delicacy of 2A3-like 6B4G output tubes is configured in a proprietary manner to deliver an amazing 60 watts, allowing these amplifiers to transcend the sonic limitations of tubes and solid state.

Amp specifications:

Inputs: 1Line Level Input
Input Impedance: 100kohms (includes input level control for level matching)
Power Output: 60W/channel into 4-6 or 8-12ohms (selectable dual output taps for biwiring)
Tube complement: 6SN7GTB (X1) (tube-swapping possible; NOS tubes preferable); 6B4G (X4) (Sovtek; should be matched quads)
Operating Voltage: 120V (60Hz)
Dimensions: 19in. (W) X 14in. (D) X 9.5in. (H)
Weight: 55lbs.

[Steve Hoffman]

Below is the matching Concert Fidelity CF-040 Linestage, $14,000.00 retail. In the photo below look at that amazing detail and workmanship, inside and out..2 12AU7's in the linestage permit exact "tuning" of the sound by the simple (and fun) process of "tube rolling". Old-style Mullards are in one of my CF-40 stages and a pair of 1963 Amperex "Bugle Boys" are in the other; the differences clearly heard with the pure sound of the machines.

According to the designer:

CF-040 Linestage:

Advanced input circuitry and volume control circuitry are implemented with our proprietary Direct Signal Path Technology (DSPT). This combines with our low-distortion amplification section using the 12AU7 in cascode configuration to produce extremely fast transient response and clarity. This preamp is the closest thing to using no preamp at all, yet it provides sufficient gain to give music the drive and authority which no passive can equal.

Preamp specifications:

Inputs: 4Line Level Inputs
Input Impedance: 100kohms
Outputs: 1Line Level Output
Gain: 20 dB
Tube Complement: 12AU7 (X2) (tube-swapping possible, NOS tubes preferable)
Operating Voltage: 120V (60Hz)
Dimensions: 18in. (W) X 12in. (D) X 5in. (H)
Weight: 22 lbs

[Steve Hoffman]

This is Tsuda's at his design test station in Japan, his laboratory and his test bench. His creations have really caught fire with my imagination; such lovely sound...Tsuda's wife's first name is Makiko. As you can see, Tsuda uses Audio Precision measuring instruments, a huge investment, but he uses it only to corroborate or correct what he designs by ear and by experience.

[Steve Hoffman]

Here are some thoughts by the designer of Concert Fidelity gear as translated into English by Mike Verretto. To start, this is a nice quote from Tsuda's writings:

"I believe that audio technology, even, to a great extent, digital technology, is largely perfected; speaker and amplifier technology have been largely perfected for a long time. With each new wave of products, the already perfected technology is just recycled. The audio engineer's job should be to serve the music, rather than to try to push our technical frontiers."

What a great quote. For me this is where art and artisanship becomes far more important than technical muscle-flexing, and perhaps explains why, with all the technical and marketing hype we hear nowadays, systems are sounding more artificial and less musical.


Mike Verretto writes:

Masataka Tsuda, founder and chief designer of Concert Fidelity, has over thirty years’ experience in vacuum tube and solid state amplifier design. Through years working in the semiconductor industry, he has access to and intimate knowledge of the wide variety of devices that are available, which allows him the creativity to use certain extremely high-performance devices not previously used in audio applications. He combines a profound understanding of audio circuits, which allows him to see where so many design “conventions” are lacking, with uncommon creative inspiration and a perfectionist’s drive to pursue the limits of circuit simplification and purity.

Tsuda-san believes that true depth of musical expression can only be experienced through circuits which do not try to artificially manipulate the signal in any way. His proprietary Direct Signal Path Technology (DSPT) is inspired by Einstein’s statement that things should be as simple as possible but no simpler. Circuits, selection of parts, and layout are optimized so that all unnecessary compensatory circuitry can be eliminated and the simplest circuitry can suffice, thus causing the least signal degradation. The result of his perfectionist drive for simplification is amplifiers of extreme transparency and the musical expressiveness of the very best SET’s without their weaknesses.


HOW I GOT INTO AUDIO by Masataka Tsuda:

"When I was young, Japan was in the midst of its postwar economic recovery, and most homes did not yet have stereo systems. Through my father’s work, I became interested in electronics and precision machining.
I first heard a stereo system while still a grade school student, at an electronics display which was part of the remodeled opening of a department store. I couldn’t believe how good the sound was, and I spent hours poring over the product brochures and dreaming about owning such a system. But since we couldn’t afford a stereo system at home, I had to figure out a way to build one myself. In Japan, which is resource poor and where the concept of recycling is well developed, there is one day per month when people leave out their old and unneeded televisions and radios to be picked up by recycling trucks. On the recycling day, I would wake up early and go around the neighborhood trying to pick up the unneeded items before the trucks came around. There were times when our yard was chalk full of such junk! I enjoyed taking those components apart to collect the usable parts inside. While other kids were reading comic books, I was consumed with reading magazines about radio technology, and in time I was able to read circuit schematics. Among the parts I collected from the junk in our yard were 6BM8 vacuum tubes, and I began to build an amp using these. At that time, the 6BM8 was used in sound amplification for television sets, and I found ten of these tubes. I also found many usable output transformers among the junk. After six months and many tripped circuit breakers in our home, I was finally able to get sound out of this amplifier! I was 10 years old at that time.
After that, I began to polish my skills and received my initial certification in radio technology, and by the time I was thirteen, I was able to build a receiver for a ham radio. At age fourteen, I received my amateur radio license, and that became my major hobby.
When I entered high school and began to have a real interest in music, I became absorbed in building vacuum tube amps. I built them using a variety of different tubes, including EL-34’s, 6B4G’s, 1619’s, 211’s, 845’s, 300B’s, 2A3’s, 45’s.What got me interested in solid state was when I was able to get good results upon designing a high-voltage IC driver for my favored 1619 tube. Shortly thereafter, MOSFET’s started to become available, and when I replaced the 1619’s with them, I liked the result, and thus began my immersion in solid state amplifier design as well. The circuitry of my first solid state amp would become the basis for my first commercial effort several years later, the Indigo-90.

In 1986, I displayed a no-feedback FET high-gain moving coil phono equalizer preamp, the SPA-4, under the Concert Fidelity brand at the Japan Audio Fair in Harumi, Tokyo. This was my formal debut in the audio industry, although I was still employed at my father’s precision machining company. The preamp was no-feedback, all FET, and incorporated TRW capacitors, Caddock resistors, and other extremely high quality parts, and was, for the time, I believe, a very innovative product. One Japanese reviewer told me that it was “too advanced a product for its time.” Without wishing to seem immodest, I feel that the product is still leading edge in some ways, now fifteen years later.

Later, while working in semiconductor sales, I became immersed in the study of audio circuits. In 1993, I completed the Indigo 90 monaural power amp and Indigo-One line stage preamp, the first products to be marketed under the Silicon Arts Design brand. I sold a few of these amps in Asia, mostly Japan and Hong Kong, while using my vacation time to make the rounds of famous high-end shops in the U.S. in order to see the best products currently offered and to seek ideas which might inspire my own products.
Since 1996, I have also been participating in high-end shows in the U.S. under the Silicon Arts Design logo, beginning with the 1996 CES. Because my company is small and I have been waiting for the right opportunity to enter the American market, I have done these shows almost as a hobby and have not expected much attention, but I have been fortunate to receive positive writeups from such reviewers as Lynn Olson, Dick Olsher, Clark Johnsen, and Dave Glackin.

(Translators note): Tsuda-san did these shows mostly to test the response to his designs, even though he was not ready for full production. Although he received many e-mails from interested customers who had heard his stuff at these shows, it was not until I wrote him an e-mail in Japanese in about 2001 that he was finally able to communicate with someone!)

Some Thoughts on Amplifier Design:

It is unfortunate that during the “advance” from vacuum tubes to solid state technology, many of the major strengths of tube circuits were forgotten. That is why it is commonly felt that solid state amps are still not as good as well-designed tube amps. That is not to say that solid state designers should copy tube circuits, but where the tube circuits of yesterday were superior was in circuit layout. They employed signal lines which followed closely a single ground line referenced to a clear ground point. The amplification stages were decoupled, and the power supplies were as simple as possible. Of course, there are disadvantages of tubes, such as the need for high voltages, which can destabilize circuit operation, the need for heaters, whose voltages are hard to keep stable, and the need for transformers, which need to be large to deliver good bass and small to deliver good high frequencies. It is rare to find a great transformer, and the proprietary one we spec’ed and have wound in Japan for our 6B4G Fusion monoblocks is the best I have heard.

On the other hand, many solid state amps use printed circuit boards, which, if designed poorly, can lead to too-widely spaced circuits. Other flaws of modern solid state amps are direct coupling and excessively large power supplies, which lead to large circuit loops. And today, ironically, many modern tube amps are copying the flaws of solid state and thus have slow transient response and compressed microdynamics which make them sound much worse than their ancestors of two or three generations ago. It is best to use the minimum necessary regulation, as well as small transformers and capacitors, all placed close to the amplification stages. Although large transformers generally improve the low frequencies, the high frequencies are sacrificed. One of the best ways to help an amp track the low frequencies accurately is to improve its ability to track the high frequencies.

The problem of slow transient response and dullness which afflicts modern large amplifiers can be traced to lack of attention to the above points. The proper design parameters of tubes and solid state contain both overlapping aspects and fundamental incompatibilities, but technical “progress” has caused technical confusion, as many designers incorporate incompatible elements into their designs. Excellent designers can build excellent-sounding amplifiers no matter what technology they use. Even with good circuits, there is still a major difference in sound depending upon the way the circuit is arranged and the relationship among the components. The best circuit designers are those who understand the fundamentals of good sound so profoundly that it really doesn’t matter whether they use tubes or bipolar transistors or FET’s; they can achieve their own particular excellent sound no matter what the device used. Circuit topology is every bit as important as the circuit itself. This does not mean just the kind of simplicity which is readily apparent upon first glance; rather, it refers to entire concept of laying out the circuitry to pursue the practical limits of accurate responsiveness to the input signal. We have called our circuitry and layout technology, based on the above principles of profound simplification, DSPT (Direct Circuit Path Technology).

The space taken up by the amplifying circuit should be as small as possible, the circuit itself, as simple as possible. Current loops should be as small as possible, in other words, as similar as possible to those in coaxial cables. The construction of the active and passive parts making up the amplifying circuit should be as simple as possible, which is often found among military spec parts. There is no way that an audio circuit or particular part can improve a signal in the course of amplifying that signal. The signal can only be degraded, and the less the degradation, the better the circuit. There are circuits and parts that impart the minimum damage to audio signals, but even when such a part is discovered and a good sonic result produced, the next step should be figuring out how to eliminate that part. Eliminating it will, without fail, make the sound even better, closer to the proverbial “straight wire with gain.” Using more such “good-sounding” parts is a mistake all too commonly made by designers.

Our circuits and layout technology are based on this philosophy that things should be made as simple as possible but no simpler (Einstein). This is more than making circuits cosmetically simple. It is an amalgam of all those factors that make our amplifiers behave as purely as possible under various load conditions while playing music.

In closing, our electronics are designed to bring out the best in all loudspeakers, particularly in the areas of accurate harmonic construction, phase coherence, and the accurate transmission of energy, all of which lead to the ultimate goal: emotionally involving musical playback.

(Translator note): Tsuda-san was originally a tube designer, but he also designs with solid state. He has two solid state amplifiers: a low-current design (a la 47 Labs but with different, proprietary technology) for very high-sensitivity loudspeakers, and a more powerful solid state amplifier which can be used in either stereo or monoblock configuration. The new solid state stereo amp will be available for audition at the Primedia Home Entertainment Show in L.A. the first week in June. For those who cannot or don’t want to deal with tubes, this promises to be something very special from a designer whose products combine profound technical understanding with uncommon inspiration and Japanese perfectionism. The solid state stuff I have heard from him is the most transparent I have ever experienced, which is why Olsher, Olson, Clark, and Glackin were so impressed.

[Steve Hoffman]

I hope the above was of interest to you; it certainly was to me! Yes, this equipment is expensive but it is a lifetime investment in good sound for the amount of a medium priced car that would be traded in after 5 years for next to nothing. This gear will give you many, many years of enjoyment...

If interested, you can contact Mike Verretto at:

http://www.audiocriticalmass.com/

[indy mike]

The lacquer finish looks gorgeous on those...

6B4G? What sort of output tube is that?

[Steve Hoffman]

Originally Posted by indy mike

6B4G? What sort of output tube is that?

It's sort of an evolved RCA/Cunninghan 2A3 that was popular in the 1920's-early '30's. Currently made by Sovtek in Russia so there is a lifetime supply. I have hundreds of hours on those tubes and nary a problem..

It has that great 2A3 sound that vintage SET lovers always rave about but much more than 2 watts a tube! The best of both worlds; no wonder Tsuda-san wanted to use it in his amplifier design..

[Larry Mc]

Wow, if only I could.................

[Steve Hoffman]

Originally Posted by indy mike

The lacquer finish looks gorgeous on those..

Yes, it does look great. When the light shines on the finish it has this 3D translucent quality that really takes your breath away. You can see all the grain and detail in the wood plus great highlights just like a fine Japanese antique lacquer cabinet. I'm a sucker for a good wood finish.

[DrJ]

Amazing stuff, boy would I love to hear it some day!

Thanks for sharing this, Steve. And as someone who hates putting money into things like cars and household appliances, I have to agree with your assessment of the "bang for buck" for audio gear like this.

[Larry Mc]

This is a great thread, someone like me would never get to see things like this if it wasn't for this forum, for that I'm very grateful. With all the what's the worse song or what's the worse band you ever heard threads, you tend to forget that there are some really knowledgeable people in here that know the art of sound. That's why I came here in the first place.
Thanks again.

[fjhuerta]

Why are all great, gorgeous things so brutally expensive?

[Mike Verretto]

I'm sure the question was rhetorical, but actually, the transformers alone in the amps cost Tsuda-san $2,500 from the vendor. They are spec'd by him and hand-wound by one of those rare perfectionist transformer vendors that Japan is known for. With tube amps, transformers, along with circuit layout, are the most important factors in sound.

It seems like most of the esoteric Japanese tube gear is priced at this level or higher (e.g., Wavac, Kondo, Zanden, Harmonix). But the time required to build these electronics is such that we will need to come up with some less pricey and easier-to-manufacture products in order to pay our bills! These amps and linestage are just for the lucky few who have the funds and refuse to compromise. I distribute them but can't even afford them myself!

Regards,
MV

[Steve Hoffman]

If it wasn't for Mike and Tsuda-san I'd be using my old Marantz 8B in my mastering room!

[Ron Stone]

Is it just me, or is Tsuda-san got a Robert Mitchum thing going?

[indy mike]

Originally Posted by Steve Hoffman

If it wasn't for Mike and Tsuda-san I'd be using my old Marantz 8B in my mastering room!

You know it's bad to let tube gear not get used occasionally to keep the caps formed - box that Marantz up and I'll take care of that so it doesn't go bad...

[Steve Hoffman]

Oh, I exercise all of my old gear, sorry Indy!

[indy mike]

Just trying to ease the burden...

[Steve Hoffman]

Thanks!

Every time I turn those Concert Fidelity amps on I wonder if we have come as far as we can in vacuum tube reproduction of recorded sound. They are that good.

[indy mike]

Have you been tempted to roll the tubes yet?