April 2007

Promitheus Audio TVC SE
Less Really Is More

Review By Nels Ferre
Click here to e-mail reviewer

Recently, I logged on to Audio Circle to look around and see if anything interesting was happening. A thread about the Promitheus Audio Transformer Volume Control caught my eye. At the time, the thread was nearly 90 pages long. "Wow!" I thought to myself, "Something is going on here." What I expected to find, as I often seem to with long threads, was a thread that starts innocently enough, eventually eroding into some type of argument, complete with insults and profanities directed from one poster to another.

I was surprised to find a thread dripping with excitement over the TVC SE. "How long until mine arrives" and "How long did it take yours to arrive" and the like were all over the place. And the fun didn't stop there. "This thing is fantastic" and similar accolades were common from those who had received their little package of joy from Malaysia. The excitement level was as if clones of Rachel Hunter were being delivered to their doors, just for them. Then I saw the price: $330 plus shipping ($390 including shipping to the U.S.) I shook my head. I must have not seen it correctly. But I had. Curiosity got the better of me. Six weeks later, the Promitheus Audio TVC SE arrived on my doorstep. I received the latest version, Revision 3, with the most up to date transformers.

Transformers are nothing new in audio. Nearly every tube amplifier uses output transformers, as do most McIntosh solid state amplifiers. However, very few preamplifiers use them.

The Promitheus Audio Transformer Volume Control
The Promitheus Audio TVC SE is a compact unit, roughly the size of a cigar box. At approximately 12 pounds, it weighs more than one expects given its size. The knob on the left controls input selection, while the knob on the right is a 24 position volume knob. The back panel is populated with four pairs of inputs and two pairs of outputs. The review sample was single ended; those that require balanced (XLR) connections will be pleased to learn they are available at no additional charge. Inside the case are two transformers, reportedly hand wound by Nicholas Chua, proprietor of Promitheus Audio, one for each channel.

Each transformer rests upon a bit of damping material which isolates the transformers from external vibration. Wiring from the transformers is copper while generic solid silver wiring from Germany handles the wiring chores from the volume control and input selector out to the RCA jacks. Internal construction is high quality, the wiring quite tidy. Included in the box are 3 pyramid shaped footers, made of the same Malaysian Nyatuh wood as the case of the TVC SE. According to the manufacturer, the TVC will sound different depending on whether the points are facing the bottom of the unit or the rack upon which it sits.

When connected, the TVC SE may be prone to humming and buzzing. This is easily remedied: for my installation, the noise disappeared when all four sets of inputs had source components connected to them. For those who have fewer sources, shorting the unused inputs cures the problem. This can be accomplished with shorting plugs, which can either be purchased or made by cutting a pair of inexpensive interconnects and soldering the hot and ground wires together.

Because the TVC SE is passive, there is no power supply and therefore no power cord. It works differently from a conventional "passive preamplifier" which is usually nothing more than a volume potentiometer, source selector switch, input/output jacks and the related wiring to make everything work. Using a passive preamplifier, the output of the source component drives the input of the amplifier directly. This isn't really the best way to get the job done: it is the audio equivalent of attempting to mow an acre of grass with a sickle as opposed to a tractor. Adding transformers to the recipe changes things entirely: they act as a buffer between the source and the amplifier, and makes it easier on the source component to drive the amplifier. Interestingly, the lower the volume setting of the TVC, the easier it is for the source component to drive the amplifier. This is the opposite of the way things work with a conventional passive preamplifier.

The thread at Audio Circle is full of tweaks for the TVC SE, what to place it upon, remove the top for better performance, and on and on. I used the TVC SE for this review as shipped from the manufacturer with the exception of the footers. The TVC SE seemed unsteady atop the pyramid shaped Nyatuh wood footers supplied with the TVC SE. I used weight appropriate Vibrapods in their stead. With the Vibrapods, the amp felt steady and sure in use. I would love to be able to tell you that I heard the difference between the two, but I didn't.

Listening
The manufacturer states that the unit is burned in for 10 hours before shipment. While it sounds promising out of the box, it takes a full 400 hours for it to fully burn in. I listened to it during the break in period, and left it cooking with my Carver tuner while I was away from home. There is a period during the break in where the performance of the unit seems to take a big leap backwards, but this soon passes. As the break in period progressed, the unit opened up dynamically, became more expanded on both ends of the frequency spectrum, and became more transparent and open. When full break in has been reached, the bass fleshes out at an incredible level, not unlike a switch has been flipped. There seemed to be a correlation with the break in period and the position of my jaw: the more the unit burned in, the closer my jaw was to the floor. If I had walked into a room and had to guess whether the TVC SE was tubes or solid state, I would have, without hesitation, said tubes- and expensive at that. I could not believe this level of performance was from such a low priced unit.

Because the Promitheus Audio TVC SE has no internal gain, I did have to change inputs on my Cambridge Audio Azur 640P phono preamplifier from "MM" to "MC": the 1.6mV output of the Denon DL-110 cartridge was just too low. With my usual line stage, the hybrid Sonic Frontiers SFL-1 Signature, (Originally $1995) the "MM" input worked just dandy, with the TVC SE, although I had no noise issues, I needed the extra amplification afforded by the "MC" input to get everything to sing. And sing it did.

Speaking of LPs, I realized in the middle of the review period that I was listening to far more of them than normal. The TVC SE has a way of reducing surface noise, or at least my taking note of it.

A favorite LP of mine is Harry Belafonte's 1959 release Belafonte at Carnegie Hall. I like it so much that I own 2 copies, the 180 gram LP reissue [RCA/Classic LSO6006] as well as Classic Records' glorious 45 RPM box set [RCA/Classic LSO-6006-45]. The LP is my "everyday" copy; I pull out the box set on special occasions. One evening, I listened to both copies back to back. I always knew the 45 RPM pressings were the better of the two, but I was floored at the low level information buried in the grooves that I had not really noticed before. I am partial to the show closing "Mathilda" and this recording really has it all, it is big and bold, and there's tons of front and back information as well. As Belafonte works the audience, and walks the stage from side to side, it seems as of he may just keep walking out of the sides of one of the speakers and just keep going. I've always enjoyed this album, but I can't think of a time when I have enjoyed it more. The TVC SE not only excels at reproduction of musical notes, but also the texture of the notes as well.

I am a huge Les Paul fan. I greatly respect his work both electrically (he invented multi track recording) as well as musically. He is one of the finest guitarists of all time, although some of his "playing" was physically impossible: it was the result of studio voodoo. Some of his playing was recorded at "normal" speed , but octaves lower, then sped up for the final product. I know some of the music is not real, and yet, I still enjoy it immensely. Going from a conventionally powered preamplifier to the Promitheus Audio TVC SE allowed me to truly appreciate the dynamics in the old recordings. Listening to "Lover" from Les Paul and Mary Ford: Their All Time Greatest Hits! [Capitol LP SLCR-8130] I noticed that the notes "popped" from nowhere- total darkness. There and gone, instantly. Is this due to the fact that the Prometheus Audio TVC SE uses no electricity, or because it is transformer based? Is it that the TVC SE has nothing other than the twin transformers and bits of wire inside the box, nothing else to alter the signal? It is just a special synergy in my system? Could it be the sum of all of these reasons? I don't have the answer, but I know that I have never heard dynamics like this, or total and complete silence between notes from any system, at any price – ever.

I had lots of "ear opening" surprises with the Promitheus Audio TVC SE in my system. One afternoon, I was listening to disc 2 of The Essential Clash. [Epic/Sony CD 89058] and reading a book. I was definitely not in "review mode." Track 6 "Jimmy Jazz" rolled around, and the book went down. I had never realized that "Jimmy Jazz," or anything that the Clash did for that matter, was audiophile quality. I played it multiple times and was amazed. It has width and depth of image, fairly deep bass, and extended highs. It was a fun discovery.

 Another fun discovery was George Harrison's 2000 remaster of his 1970 solo debut All Things Must Pass.[GN3 LP Box 07423 530476] Before his untimely death, Harrison himself revisited the master tapes and remixed them, removing the Phil Spector "signature sound." It was nice to hear the music as it was recorded, without the coating of schmutz that Spector spread upon everything he touched. Although I have owned this LP since its re-release, I enjoyed it more through the Promitheus- it seemed more real, more alive than I recall hearing it previously.

Dire Straits Communique [Warner Brothers LP HS3330] is, like every Dire Straits release, very well recorded. The opening track "Once Upon a Time in the West" showcased the detail retrieval capabilities of the TVC SE. It starts out with a nice reverb enhanced guitar riff that continues as the rest of the band falls in. As the lead progresses, it becomes very obvious that the lead was recorded as a solo track, then integrated into the rest of the track when it was mixed. It stands apart from the rest of the music, yet works with it as well. The Promitheus, while very revealing and detailed never becomes fatiguing which many high resolution components can, in my experience. It lays everything bare, yet remains true to the music, letting the listener become more involved in the listening experience rather than becoming irritated or bored by it.

I did have a problem with reviewing the TVC SE. I am used to being able to find sonic faults in a review component. I truly can find no fault in the TVC SE, performance wise. That's not to say that everything played through it sounded wonderful. That is definitely not the case. Take, for example, the 180 gram reissue of the Rolling Stones Exile on Main Street. [Virgin LP 7243-8-47864-1-0]Please, take it. This one is a dud- dark, muffled, unclear. I can't believe someone signed off on this. The TVC SE didn't make it any better, although I'm not sure if it made it any worse. It just sounds bad. An original pressing or even the CD are far better. I'm not saying that Virgin does a poor job, because I just rolled the dice and bought their reissue of the Stones' 1978 release Some Girls to replace my worn original copy [Virgin LP 7243-8-47867-1-7]. I have no complaints whatsoever. They have done a fine job with this one, with heavy, flat and quiet vinyl. While I would never say the album is "audiophile quality," it is a nice addition to my collection.

While I was at the store, I purchased, among a few other albums, the LP version of Nora Jones' Come Away With Me. [Blue Note LP BTE32088]An expensive dud here as well: the vinyl is thin and the recording sounds decidedly digital. Stick with the CD on this one. The TVC SE isn't going to "fix" any deficiencies in one's recordings or system. No added spice or flavor. Garbage in, garbage out. That is the TVC SE's stock in trade. With decent source material, I was pleased. With exceptional recordings, I was amazed. Clear, smooth, dynamic, and extended on both ends of the frequency spectrum, the Prometheus Audio TVC SE has it all. Of course, because it is passive it is totally silent, regardless of the source material.

I also enjoy watching movies as well, and connected my Philips DVD player to the Prometheus. With a Sony 40" LCD screen, and the Promitheus in my system, I discovered I actually enjoyed movies more at home than in the theater. The movie theater has a bigger screen, but I had far better sound. On numerous occasions, I thought "Wow, bass extension like this, and no subwoofer." The clarity of the Prometheus Audio TVC SE made it easier to decipher difficult dialog. To say I was mightily impressed would be an understatement.

With the Promitheus Audio TVC SE in the system, one will hear the true sound of their system, as well as the recordings played upon it, whether good or bad. For those who have systems with which they are generally pleased and yet want to get closer to the music, the Promitheus Audio TVC SE may be an excellent fit. For those who feel they have deficiencies in their systems (too bright, bass bloat, etc.) this piece may not be their salvation, unless the problem lies with their preamplifier.

Many audiophiles believe that the purpose of a high performance audio system is to recreate the sound of a live performance in one's home. I feel sorry for them, because they are setting themselves up for disappointment. I have heard some systems that come damn close, but they cost well into six figures. For those of us who work regular jobs, haven't won the lottery, and are not trust fund recipients, all is not lost. While components in this price range cannot truly recreate the sound of a live performance, the very best of them can make you believe you are listening to the master tape. Partnered with the right gear, the Promitheus Audio TVC SE has that special quality.

Dislikes
As much of a incredible bargain that the TVC SE is, it is not perfect. If it was, Promitheus Audio themselves wouldn't offer a Reference version. Cosmetically, I wish the knobs had a bit more of a polished appearance to them: they actually detract from the higher quality appearance of the rest of the unit. Keep in mind this is a hand crafted piece. While the appearance of the unit is far from "jewel like" in precision, the knobs are substandard, both visually and in the way they feel to the touch. Appearance wise, the Promitheus TVC SE reminds me of Wood Shop, which all seventh grade boys were required to take when I was growing up. If I had made the cabinet and knobs for the TVC SE as one of my projects, I think my teacher, Mr. Dugger, would have given me a solid C. He was tough, but fair. On the other hand, if you want a TVC SE that looks like a million bucks, there's always the Sonic Euphoria ($1295 Single Ended, $1995 Balanced) or the $2995 bespoke six input offering from Bent Audio. The Prometheus Audio TVC SE is less than four bills shipped to your door. The transformers alone in the Bent Audio TVC cost hundreds more. You can't have it all. Those who "need" audio jewelry to impress themselves or others should look elsewhere. Music lovers who can be "blind" to appearance if the music is satisfying may be truly ecstatic.

The volume control vexes me a bit. Even though the specifications clearly state 2dB graduations, most of the range of the volume control seems to be biased towards lower and mid level listening. This is perfect for me. I live in a condominium, and my unit is on the second floor. Irritating the neighbors is a concern, although I have never had a complaint, as the sub floor is concrete and the walls are constructed of concrete block behind the drywall. Even so, I wish Mr. Chua had designed the TVC SE with more taps off of the transformers and a different volume pot, for more flexibility. The first volume setting, depending on the source material, can still be a bit louder than I would like. As I write this, in the wee hours of the morning, I am listening to Andres Segovia, and I am not concerned about disturbing others. I wouldn't dare, however, play louder, more dynamic music such as The Blue Man Group, even on the lowest volume setting. At the same time, I never get the feeling that I am getting full output of my power amplifier on those rare occasions when I want to let it rip.

Keep in mind, at this price, these are minor quibbles indeed. As an example, I remember hearing the NAD 3020 integrated amplifier at an audio show that took place at an Arlington, Virginia hotel in 1979. The performance of that amplifier simultaneously amazed and irritated me. The amplifier, at $199 retail, performed far better for its price than it had any right to. Unfortunately, I had just spent my labors of months of lawn mowing and house painting on a Pioneer receiver. I made a big mistake, and I knew it immediately. If it were available today, according to an on line inflation calculator, the NAD would cost approximately $470.The little red box under review is only $330 plus shipping. I've heard many components from many manufacturers that are good values for the money. The level of performance of the Promitheus Audio TVC SE, for the money, is in a different league altogether: it is nearly theft, as was the NAD 3020.

One of the contributors at Audio Circle had upgraded his Reference TVC ($540 plus shipping) to a custom one of a kind 2 box version, and had offered to allow those interested to try the Reference TVC n their system. He had graciously agreed to add me to the list so that I could compare the standard issue TVC SE to the upgraded version. Unfortunately, it arrived damaged. Although well packed, the gorillas at DHL had, I believe, dropped it quite a distance. Upon its arrival, the Reference unit was not operating properly and therefore deemed unsuitable for comparison.

Conclusion
Do not let the low price of admission or the handmade appearance fool you. The Promitheus Audio TVC SE is not a curiosity or a toy. It is a serious audio component, and probably the very best bargain in audio today. It doesn't have the visual or tactile panache of its more expensive counterparts, but sonically, it runs easily alongside the "big dogs." The nature of its design results in total and complete transparency. Because of this, the quality and compatibility of the rest of the system components is critical. Vinyl lovers will need to pay special attention to both the output of their cartridge as well as the gain of their phono stage. However, at the end of the day, I find the Prometheus Audio TVC SE to not only be a joy to "listen" to, but also an invaluable reviewing tool. I will be keeping it, and I suspect it will be hooked up most of the time. This component gets my very highest recommendation.

Manufacturer's Comment
Thanks for the nice review. The review is thorough, fair and a learning experience for us. As you know we have created the TVC to a price point.

The feel of the volume control can be improved by incorporating a different attenuator such as a Shallco or equivalent. Our plan for a Statement version will include a Shallco or the like. We acknowledge that our cosmetics need to be improved and we will be spending more effort making these improvements. With reference to the feel of the knobs, we have purchased a CNC milling machine and CNC lathe to manufacture our own knobs in the future, to improve the look and feel.

Several of our customers have commented on the lowest volume setting being to high. We will be offering additional attenuation to the transformer. Attenuation will be revised from -48dB to -60dB for late night listeners.

We are looking into refining the wood enclosure as well as different materials for the future: volume selection markings, logo, RCA identification and so on.

We will continue to offer "bang for the buck" with our original line with a possible price increase if warranted by the cosmetic enhancements.

As mentioned, we are in the process of developing a Statement and Reference line. These lines will include an all out assault on the TVC and Active Buffer combo, a tubed DAC, and SET amps, both high and low powered. There will also be a phono stage, a CD player with transformer output and redesigned ebony cones and knobs.

We feel the future is bright as we will continue on our journey in providing great sound that is affordable. We cannot thank you enough for helping us reach our goal.

Thank you again for your honest and thorough review.

Nicholas Chua
Promitheus Audio

Specifications
Type: Transformer based passive volume control

Inputs: 4 stereo pair

Outputs: 2 stereo pair

Control Adjustment: 24 steps

Attenuation Level: -48dB to 0dB (in 2dB increments)

Internal Wiring: Pure Solid 4N German Silver

Transformer Wiring: Pure Solid 4N Copper

Case: Sides and knobs constructed of Nyatuh wood, with top and bottom covered with stainless steel plate

Price:$330 plus shipping

Company Information
Prometheus Audio
Malaysia

E-mail: nicholas@promitheusaudio.com
Website: www.promitheusaudio.com