Tecon Model 55 Tube Amp For PC Review

Audio/Speakers&Amps by KeithSuppe @ 2009-01-09

Tecon Model 55 is an integrated SET amplifier, SET standing for Single Ended Triode. The euphoric sound produced by SET (vacuum tube) amps is often compared to that of OTL amps. Sans the transformer, Ouput TransformerLess amplifiers are highly regarded as a purest since little stands between the vacuum tube and Listener. The Model 55 is a rare find for at least one reason, its $398 price tag

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Internal views

Topology \ Build Quality

Madshrimps (c)


Tecon chose Audiophile quality Rubycon capacitors keeping the signal path clean and costs down. Additionally the Model "55" circuitry is based primarily on a PCB. Vacuum tube Purists (myself included) would eschew printed circuit boards, for point to point wiring wherever feasible as point to point generally produces a clean, accurate sound. This is because a PCB is essentially a semi-conductive medium and while it is ideal for countless applications including digital audio, when it comes to signal integrity shielded copper/silver wire offers many more benefits for Audio. Where Tecon did employ point to point wiring, the wire gauge is more robust then I've seen in similar products costing much more then the Model "55". Tecon designers struck a balance incorporating a PCB and heavy gauge point to point wiring where it was sonically and financially viable. The Model "55" exemplifies one of those rare sum its parts products.

Madshrimps (c)


Insofar as topology is concerned, what often looks superfluous in audiophile circuitry such as wire gauge/material, capacitor type or brand can have a marked affect on sound. If there is a singular vision among High End manufacturers then it is to build a sonically neutral product. One which does not add or subtract from the music, even where certain characteristics may "sound" more soothing. The ultimate goal is to hear music as it originally sounded in the recording environment. This not only requires neutrality it also demands our system be capable of reproducing every minutia of detail. In our desire to hear every nuance in the music at some point we reach an inevitable caveat. As your system reveal's more information this includes just about any weakness in other components. This may include your cables, speakers and/or the recording itself. These types of scenarios are what separates High End Audio from Audio and the Audiophile from layperson. I've provided many examples of Audio extremes in design, in cost and in materials, for our purposes I found example where point to point wiring is used in a "Purist" example of an integrated vacuum tube amp using EL84 tubes. Leben Hi Fi Stereo Company offers a 2x 15W integrated in their Leben CS300 X, reviewed by 6moons, I've provided photos below taken from that review. For more detail check out this high resolution photo of the CS300X. At a cost of $3295 the Leben is not expensive as far as High End, although its not a single ended triode amp, nor does the Leben CS300X incorporate a USB fed DAC.

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Back to out Model "55", Tecon chose a vacuum tube circuit board which accommodates just about all the main circuitry including input vacuum tube driver section and output devices (vacuum tubes/capacitors?). There is a transformer mounted on the main PCB as well as the 12 Rubycon capacitors. The daughter board at the front of the amplifier serves the Audiophile quality Alps attenuator. As I have indicated in previous articles I prefer stepped attenuators to less expensive potentiometers which use a thin film of carbon and metal scraper for volume adjustment. Potentiometers by virtues of their design alone tend to introduce unwanted noise into the signal. The advantage of stepped attenuators is that they use fixed resistors and contact switches resulting in more accurate control and because each step is isolated they go a long way in preserving signal quality. Not all potentiometers are inferior to stepped attenuators, Alps makes some high quality potentiometers for Audio. The photo below captures the main PCB and volume potentiometer daughter-board. Thumbnails provide more detail.

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In the main photo below we look to the rear of the amplifier, including two mains transformers as well as the input/output connectors. I removed one of the Tecon stickers from a transformer revealing it was intended specifically for the Right channel. Thumbnails below provide close-ups on the internal RCA inputs and left speaker outputs, Main AC circuit board, and USB and left channel speaker connectors. Whether the connector accomodates the input or output, point to board heavy copper wire is used throughout.

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Throughout the process of photographing the internal circuits I was unable to locate the Burr Brown PCM2707 DAC daughter board. After tracing the USB input I discovered these circuits were placed up under the transformer cover at the rear of the amplifier. Most designs install a transformer cover to isolate the transformer for noise purposes, to protect the device from the elements (dust) and/or keep out of reach for safety reasons. Whatever lives under the Tecon Model "55" faux transformer cover, shares that space with the digital to analog converter chip.

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Onto listening tests ->
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Comment from 4PLaY @ 2009/01/10
Please forgive my ignorance, I do understand a little of what you were talking about but let's face it, im no audiophile, the PC though I understand, and I know traditionally it requires a soundcard to spit out audio, I know as well that an amp with vacuum tubes sounds magical.

So how does this thing work, plug it in USB, and what? do I still need my soundcard? is this 5.1? will it play anything other than music, can I use it to for gaming. where does the audio processing take place? I know this sounds really noobish, but please humor me.
Comment from Liquid3D @ 2009/01/16
Hello.

Nothing you said sounds "noobish." Actually these are great questions. IMHO anyone who loves music and is an electronic hobbyist is a Audiophile. Anyway the term can be a badge of honor or an insult, depends on the context

The ethos of High End Audio and how a Single Ended Triode amplifier is designed and constructed could fill volumes, so I hope this helps.

The Model 55 has a built in DAC and USB connect. This gives you the advantage of a highly musical external DAC as opposed to the very best soundcard which still makes it's home in the EMI saturated environment of the PC. I am willing to bet the very best soundcard cannot compare to any recent integrated tube amp with DAC.

There are several advantages of owning a tube amp with built in DAC. Access to music: there is now an endless number of music files out there, and there is streaming audio as well. Depending on the Server you can downloading music files compressed using formats other then MP3 type. MP3 as a compression discards larger amounts of data then some and this makes the file smaller for economics and they know most people don't have a neutral Audiophile playback system. You don't have to be an Audiophile to hear differences in a song compressed using MP3 vs Lossless. As I stated above the point of file compression is economics and you store more music with MP3 then Lossless, but at a loss.

Vacuum tubes have been hailed (arguably after solid state emerged) as the ultimate electronic device for reproducing sound. When a quality tube amp is matched correctly with other components (synergy is everything) the vacuum tube amp signature sound breathes life into recordings. In a SET design the circuitry is similar to what is known as a push pull except the vacuum tube interacts directly with the speakers.

As far as Gaming and surround sound, most audiophile amps are designed for Stereophonic playback signals. I've gamed a few times using two speaker stereo set-ups and still enjoyed the "experience."
Comment from cowzzwoc @ 2009/01/18
I would absolutely love to have an amp like that. However, what i would really like to see is a comparison between the Xonar STX and the Omega Claro Halo sound card. Both of these cards are geared toward producing near audiophile quality sound while keeping costs down.
Comment from Liquid3D @ 2009/01/20
The point of these types of amps and the articles I'm doing is to get you to think "out of the box" where the D/A processing is concerned. The Tecon Model 55 has a very solid (more importantly Musical) DAC built in and using the USB means (in theory (since digital signals can be affected)) keeping the integrity of the digital signal in-tact. At least until it reaches a superior design such as the Burr Brown DAC found in the Model 55. Many external DAC makers choose from a number of older DAC's such as Burr Brown (Texas Instruments now) and Phillips based on their performance. Because a DAC (or music chipset) is new or has higher sampling frequencies has absolutely nothing to do with the end product, its Musicality.

I used an example about DAC's engineers choose in another review, taking what is currently one of the most respected (and costly) DACs on the market designed by one of the most astute digital Audio engineers out there. The $15,000 Zanden 5000 Mk IV DAC. Just reading the Stereophile article about the DAC and Zanden transport (the transport runs $27,000) will educate you on the engineering extremes in High End and the price some will pay whom can afford it. People whom design such products are usually Music Lovers themselves and every product undergoes listening tests as the final determining factor. They design by ear. People whom buy such products love music and have lot's-o-cash, but not all. Some listen and buy $5k ~ $20K DAC's like some people go through bottled water, but not all. I think most wouldn't simply choose the Zanden because it cost more and they want to show off, such hardware MUST be carefully matched or the faults are more quickly revealed. How do I know this? I used to be a Audiophile and invested $20k into some of my systems and those were comprised of used gear. I eventually brokered Used High End gear which gave me access to some very exotic hardware.

Anyway it wasn't the extreme in engineering, it was the performance (sound) that hooked me. Eeventually the Hobbyist in me found a love for both. When you read about the Zanden, how the chips were used you understand there's more to digital processing then installing the latest chipset and thinking it's the best. Why? Because the DAC in that $15k Zanden are circa 1985 (no longer made since 1990's!) NOS (New Old Stock) Phillips 1541A chipsets. Of course their hand selected because anyone who thinks chips don't perform differently has never overclocked a CPU or GPU of the same make and model, different manufacture dates. But what is amazing are how he engineered and used what most would see as an antiquated DAC. The concept is, we haven't fully exploited 44Khz so what's the point of getting so far ahead of ourselves.

I'm not saying PCI- slot cards or internal cards don't sound better then one another, and the sound can't be good, but its only as good as the rest of the system, the powered speakers. It won't matter what card you use if your limited by your speakers, or vice versa.

Now if its Headphones your interested in, thinking this card will breathe new life into a pair because they placed an op-amp for Headphones on the card is not the answer. You can buy a Tube-stage head amps for little more then the $200 Xonar which will completely eclipse it's performance. In many circumstances with soundcards people pay for features they won't even use. How many do you think have truly great sounding 7.1 surround.

Most music is encoded in stereo, an amp like the Tecon or any stereo vacuum design brings you back to basics in this respect, and I can attest surround sound doesn't touch stereo unless the system (speakers and multi-channel amp) are made by a company like Meridian. Problem is such "all" digital systems are very costly.

With a $389 SET amp and a pair of $400 speakers you can access unlimited music in its digital form and hear that music through a true Audiophile level system. Since D/A conversion takes place externally from the PC its "cleaner" by definition.

Have you ever heard a PC-Audio system image? I have written sound card makers, but at present I don't have what I'd call High End sounding externally powered speakers. I purchased my Audioengine 5's as seen in my review and they may interest you. I can recommend other powered speakers and all you need is a decent Turtle Beach Santa Cruz and it still best a system with a Xonar and mediocre speakers.

Until you've heard a true High End system (even if its beyond your cost) to understand what Audiophile level sound is, its impossible to share that experience by writing about it. I know I've failed in this respect. If you can take a few moments to find a high end shop were they know what their doing, and are willing to give you some air time that would help. Its like anything else, for example ice-cream. Until you've had fat rich all natural Ben & Jerry's or Haagen Daz, Hood ice cream may taste great.

Hearing each performer in their perspective place as if they were in the room changes any music lover. You should never "hear" sound coming from the speakers, technically the speakers (no matter how large) should vanish, get out of the way of the music they are producing.

This depends on many factors, how the music was recorded being foremost. Today so much POP is recorded on separate tracks then mixed, a High End system will only reveal this and the sound will be surreal because it is. Live microphone recordings will sound best on High End gear. High End is a double edged sword, like an Addict who experiences self-actualization (self honesty) its impossible to go back and enjoy the old experiences.

With soundcards you need powered speakers. And even with the best placing an amplifier in any speaker is inherently risky because of the vibrations, or sound waves especially reverse.

I will however find out more and get back to this thread as to which card is superior. I can tell you straight off the Omega Claro Halo probably wins for cost v. performance, but I'd hope you would read the article I linked above because it expands your knowledge. Once you read some other articles at Stereophile you'll be amazed at that hobby I'm sure.
Comment from cowzzwoc @ 2009/01/20
i really have fallen in love with the audiophile hobby. i've been reading reviews from 6moons and stereophile left and right. But, it will be several years before i can ever hope to have a high end speaker set up.. college and graduate school are going to be the primary focus of my budget for the next 5-7 years.

i'm pretty much limited the best headphones + soundcard/amp setup i can get for around 400 dollars.

i just upgraded from my old sennhauser pc150 gaming headphones to my grado's and the difference is breathtaking.

i love going to the only truly high end audio shop in New Orleans "wilson's audio" and listening to their audiophile setups.

i just want to get as close as i can with my extremely limited budget. the xonar stx and the claro are both probably leagues ahead of my current xfi solution.

is it worth paying the extra money for an amp like the tecon when the only headphones i own are a pair of sr60s? like you said the quality of the sound is only as good as the weakest link.

im just worried that getting a SET amp like the tecon would be overkill

and for the recored, i HATE pop..

i listen to mostly jazz, classic rock and classical, although i have a soft spot for funk and blues
Comment from Liquid3D @ 2009/01/20
Given your musical tastes and your ancillaries (headphones) I think the $389 price-tag for the Tecon Model 55 (shipped in USA!) would not only be a great investment for you, it will be a leap in performance! I truly can say this is currently one of the top ten best buys in all of High End audio. When it was $800 it as a good buy. I don't think their going to make anymore and are depleting stock at this price. I wouldn't let the opportunity get by. I don't say that lightly. I've been into High End almost 20-years.

I first fell into buying used stuff (couldn't afford new) when in circa 1990 I listened to a pair of Krell monoblocs driving Apogee Stages (full-range ribbon speakers that would drop below an 0.1 Ohm) and found myself with an Aragon 4004 stereo amp (budget Krell same designer) driving Apogee Centuar Minors in my home a week later. The Aragon just didn't compare with the real Krell even with a Meridian CD-transport / DAC-pre-amp combo so I went to the Krell KSA 250. When I finally found the Sony X777ES ($3,500 new in 1990) which someone traded in, I was in heaven. This showed me digital sources are very different and the difference beyond the build quality of course is cost.

Then I heard a pair of VTL mono-block vacuum tube amps and immediately traded in my Krell and went all tube. I'd NEVER go back unless it was a PASS Labs amplifier or maybe a Threshold Stasis. I've listened and owned many different solid state amplifiers from Bryston, Aragon, Boulder and Threshold to name a few and for vacuum tube amps Cary, Sonic Fronteirs, Audio Research, Melos, Audible Illusions, Magus, and a pair of prototype NYAL (Futtermen built) OTL monoblocs which were in my last full range system.

I can attest the Tecon is right up there in build quality and sound quality with these amps, and its DAC is very good using the Burr Brown PCM2707 chipset. This list of DAC chips is a great resource, it's arranged by cost of the external DAC or Soundcard and will exempplify which DAC chips are used in which products to give you an idea. You'll find Burr Brown and Phillips probably dominate the list in the high end range.

Of course every tube amp has different characteristics and I have not listened to the Headphone jack on the Tecon. When I was deep into High End, integrated tube amps were very rare (at least decent or inexpensive ones), today there are designers taking advantage of Eastern Manufacturing costs which is why there are several out there, including the GLOW Amp One which I'm done testing. Of course the draw back to any SET amplifier is speaker mating. It's possible 5W per channel can fill a very large room with large sound if mated to the right speaker, a highly efficient speaker, but probably a costly exotic Horn. Problems can arise finding highly efficient speakers because of cost and many lack deeper Bass, so there can be trade offs. But I'm working on a match right now, because the Cain & Cain Abby's I mated with this amp retail for $1500. But driving headphones will be a breeze (in most cases) for the Tecon Model 55.

If I were you I would invest in the Tecon for $389 shipped in the USA it's USB fed Burr Brown DAC gives you access to all musical files in their digital form. Removing the Digital to Analog process which is why the Xonar and other cards like the Razor soundcard have sheilding. I will say the fact the Xonar STX is sheilded and uses Burr Brown PCM1792 DACs bodes well for soundcard, but its still in the box and as you know inside every PC is a EMI storm.

The op-amp for driving head-phones is also a great feature since its rarely ever been done to this extentso I can see why your excited about it. As I said earlier DACs don't mean anything because sampling to 192Khz has little to do with the potential musicality of the hardware.

The Tecon is a single ended vacuum tube amplifier and as such its goal is music reproduction. The Tecon uses Burr Brown PCM2707 DACs (probably sound better in stereo) and between the two the Tecon should out perform the Xonar by a mile.

Lets not forget about the source, its great to have worthy DAC but if the music-file itself is hinky thats what your amplifying. MP3 files v. Lossless is what I mean and finding Audiophile grade music Servers which offer AAC or Lossless files will undoubtedly make a difference. The better your hardware the more revealing so as I said its a double edged sword.

Given the music you listen to I'd say tube amplification is just what you need and the USB connect as well as RCA inputs give you so much more versatility then a PC-card when you can eventually afford a decent pair of speakers, although they will be limited in the Bass region. As you spend more time in High End you'll find it's very rare you find a system capable of producing Bass down to 20Hz, at least not without spending large sums of money. Most people don't realize how low 20Hz is and what it takes to "move that much air." Getting back to speaker matching for the Tecon, there are plenty of great speakers which will go down to a true 40Hz at around $1800 (were talking high efficient 100dB one watt at one meter). I'm looking for decent (with decent Bass down to 40Hz) speakers for the Tecon which run at around $400. I was looking into these from AV123 the x-mtm which are 90dB efficient at 8 Ohms. Their a little more then my $400 goal, but at $600 your getting floor standing with a D'Appolotto Bass/Midrange and tweeter, and these speakers as well as the site attracts many DIY Audiophiles. They want me to test a new amp Class-D the Gizmo V.1 25W (only $110) with a new tower speakers similar to the x-mtm's pictured below.

Comment from jort @ 2009/01/22
Quote:
Originally Posted by Liquid3D View Post
.....
It's been a while that i saw you here

How are you ?
Comment from Liquid3D @ 2009/01/23
Things have been very tough. These have been the most challenging years of my life. I moved from Newport R.I back to my home in Connecticut to take care of my Mom whom has stomach cancer and diabetes (among other ailments). The hardest part has been trying to get her to follow her diet.. I also dislike Connecticut very much, I guess its quaint, even picturesque with its old tobacco barns in disrepair, but the Southern part is a bedroom community of NYC made, old money. The North Eastern half is country and Country Music plays on the Radio out there. No real mountains, no real ocean (well there's Long Island Bay) but there's plenty of cars, pollution and more cars. Everything I escaped from back in 1986.

Since leaving I have been fortunate to find each place I've lived over the years (with the exception of Hawaii) have been towns so small you don't need a car. And all were either by the open Ocean or eclipsed by mountains. I can't surf, or ski anymore because of my spinal injury, but being surrounded by nature instead of people is definitely preferable. I want a home in Bar Harbor Maine. I am no longer a Materialist (except for my current philosophical stance).

I don't have children but I now know what it's like to really worry about someone.

Thank you for asking, how are you?
Comment from jort @ 2009/01/23
wow what a journey :O

it's Ok with me, i sadly quit overclocking and super chilling methods....

I live on my own now for about 2.5 years and i am self employed in the insurance business, pensionsavind and healthinsurance.... totaly something different but does it matters ?

See you around next time, sometimes i have the feeling what it would be like to still overclock pc's and play with ln2...

grtz !!
Comment from Liquid3D @ 2009/01/23
I prefer living alone, how do you like it?

Since moving here to take care of my mother, I rarely get calm "alone" moments where I can center myself. In Newport I could take a walk to the Ocean or Bay both 2 ~ 5 minute walk. I never required an auto in Newport and avoided sitting in traffic which has to feel like the single greatest waste of time ever. Connecticut is a traffic nightmare on the seaboard (I-95), it's the typical bedroom community for Rats in the Rat race. Here we exemplify extremes of Capitalism, Materialism, and the circumlocutory effects of an "addictive society" on the family. Quite a mouthful (somethings change slowly).


As a hobby High End Audio is most exciting and an endless number of exciting designs out there of which a music lover and electronics enthusiast would find fascinating. And your listening experience will become just that, an active experience opposed to just hearing music.
Comment from 4PLaY @ 2009/01/28
Quote:
Originally Posted by Liquid3D View Post
As far as Gaming and surround sound, most audiophile amps are designed for Stereophonic playback signals. I've gamed a few times using two speaker stereo set-ups and still enjoyed the "experience."
Whew! thank you for explaining things to me, it does clear up a lot of things. Ok so far here's how I understand it now. This will serve as my soundcard only it's via USB.. correct? so all audio processing will take place on the Tecon? or Porcessing will take place on my PC and just spit the information out via USB for the Tecon to amplify?
Comment from Liquid3D @ 2009/01/28
Hello thank you.

Yes ALL processing take's place on-board the Tecon Model 55 via a Burr Brown DAC, there's no need to worry about software. All you do is go into Windows and choose USB as the Audio Device. That's it no software or hassle. It doesn't matter if the music files are stored in MP3 or another format. This product elinimates the need for a soundcard. If however you have a soundcard with RCA left and right outputs, or a 1/8" jack adapter cable (1/8" into RCA left/right) analog you can use that soundcard for D/A conversion and use the Amplifier's RCA inputs.

Its so easy to connect and run just like "butta."

 

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