Amp Builder Spotlight: Lance Cochrane, Oliver Sayes, Radu Tarta

By mrgoodsound

Time for some cheap tube audio! I would like to share about some independent amplifier builders I have worked with in the past. Although 'cheap' is subjective, the builders I discuss here put out amplifiers that could be considered affordable by most!

I have little to no interest in commercial or mass manufactured tube electronics (this does not apply to vintage electronics). This is because even if you cannot DIY (my skills are limited) or have no interest in building electronics yourself, there are a number of talented craftsmen in the audio community who put out products that out perform anything from the brand names.

Working with an amplifier builder has its pros:

• Great deal of flexibility and customization, you may get a unit specifically tailored to your system, speakers or taste. This includes aesthetic and functional considerations too. 
• Free from overhead manufacturing, marketing and distribution costs; the hobbyist or semi-pro builder may pass those savings onto the consumer when he or she buys direct. 
• Potential for higher performance. Most brand names are re-hashing the same 3-4 circuits for a given power rating, with minor differences in parts quality. This assures a certain 'safe' performance and sales. The hobbyist or semi-pro has more freedom to explore designs and think outside of the box

And some cons:

• Limited opportunity to demo their wares beforehand. Usually a purchase decision must be made based on direct conversation and the recommendations of others, which is not an ideal position, especially for a big purchase.
• Limited resale value. You can only sell to someone who is familiar with the builder's work, and even then at a rather steep discount to what you paid, considering additional costs for customization the potential buyer may not care for
• Potential for lower performance. Freedom of design means that you may end up paying big bucks for someone else's prototype or design that seemed good on paper but did not sound well on execution. 
• Potential to go 'overboard'. Given the opportunity to specify what they would like in their amplifier, it turns out that most audiophiles don't have a clue; and are usually too focused on the tubes and parts used, or making their dream amplifier that is not really the right fit for their system. The conversation usually goes something like this:

Prospective customer: "Hello, I saw on your website that you build custom amplifiers. I have always wanted to try a 45 amplifier. I listen to loud rock music with 92db/w efficient speakers. Please help!"

Amp builder: "Yes, I can build you an amplifier, but have you considered a simple 6L6 push-pull circuit for your speakers instead? A single-ended 45 amplifier may not satisfy your listening requirements. I can build a number of push-pull amps with good sounding iron from Hammond or One Electron. Check out my projects page and let me know what you think."

Inside the Sun 2A3 clone - so neat!

Prospective customer: "No, push-pull doesn't sound good, I don't have any experience with it myself but the people on forums say so. I want a single-ended 45 amp. I heard one at my friend's house and now I have to have one. BTW can you source Tribute transformers for me with nano-crystalline cores? And please only use Mundorf film capacitors in the power supply."

Amp builder: *facepalm*

Oliver Sayes

Oliver Sayes aka sonic_oli is based in New York and is really talented! His main offering seems to be Yamamoto/Korneff 45 clones using old stock Tamradio output transformers. It's really amazing that in this day and age one can get such a high quality single-ended amplifier for under $1000 USD from a talented builder. I always see his 'plain jane' amps sell in under a week when listed, though I know he is open to custom orders and I have seen some crazy two-chassis creations from him.

I owned a simple Sun Audio 2A3 clone he did with bargain basement parts - Hammond OPTs, Russian PIO caps and an ALPs pot. Nothing fancy, but it sounded sweet! I would like to try one of his amps based on the 45, 46 or 42 tubes sometime.

Radu Tarta

Radu is based in Connecticut can be found on his blog simplepleasuretubeamps. I would consider him a 'modern' amp builder - he uses very fine modern OPTs, DC heating, filament regulation and overbuilt external power supplies for his amps. As a result his creations are a little more elaborate and definitely not 'cheap', but seriously beautiful.

Radu Tarta 4P1L line stage

I owned a line stage from him using the Russian 4P1L direct-heated pentode, triode-connected and plate loaded into a Lundahl line transformer. It sounded really good, competitive in terms of neutrality and rightness of tone with The Truth line stage, with some 'direct-heating' and transformer flavor. In the end, I sold it on because it did not have remote volume adjustment, which was more important to me.

Lance Cochrane

The next builder I would like to highlight is Lance Cochrane from California. Lance has been building 'scratch amps' for several years and selling his one-off creations on Audiogon. He no longer takes custom/individual orders but if you are lucky you may find one of his amplifiers floating around for sale. They usually go quickly. 

I like the scrappy style of Lance's creations. He reuses the chassis' and transformers from old console, organ and jukebox amplifiers; cleans out the inside and puts in a variation of his favorite circuit he has been working with for years. I have seen his amps feature 6L6, 6V6, 6550, 6BQ5, 6AQ5 and more, typically in a push-pull configuration for somewhere between 10-30 watts.

I currently own an amp of his called the 'Leviathan' which I think is rebuilt on a Conn organ amplifier chassis. It is 6550-based and features a whopping 11 tubes, 3 of which are rectifiers! When I was young and naive, as opposed to now where I am just young, I was anti push-pull for no rational reason. Yes, in general, they sound a little more restrained and a little less free than their single-ended counterparts, but I do not feel this way about Lance's amp. It is capable of sounding psychedelic and graceful, despite having enough current on tap to drive just about any conventional loudspeaker. The best part is that Lance builds for trouble-free operation, automatic bias on everything, no adjustments to make, output tubes run softly.

Finally, I will share an excerpt of an email from Lance where he describes the signature of his amps:

"What makes the power number? The higher the plate voltage, the higher the power. KT88/6550 for instance will be run at 600v on the plates commonly while 6V6 can't take over say 325. That's a starting point. How much the output tubes take and what you give them are separate things.

I tend to not give output tubes anywhere near their maximum ratings. The harder you run them, the harder the sound and the sooner that they wear out. All in the pursuit of more watts.

Looking a little deeper, the voltage difference between the plates and screens determines the class the unit runs in. If you have a big difference in voltage there, like Audio Research tends to do, you get more power. As always, more power comes at a cost.

I like to run the plates and screens with some difference, say 50 volts, but not a lot. That cuts effective power but adds depth. Having the plates and screens at the same voltage would give Class A operation. I've always found that on the bland side.

Mode of operation gives an amp a signature. Voltage on the first tube in the chain gives an amp a signature. Triode versus tetrode versus ultralinear gives an amp a signature. Biasing level gives an amp a signature.

My amps are all tetrode, all run at a soft level of plate voltage, all run at a discrete level of voltage on the first tube in the chain, and all are biased at roughly the same level on the tube curve.

They also are all cathode biased, have low global feedback, and have the same phase inverter.

There are a number of reasons my amps all sound more alike than different. It's all in optimizing the various factors of each unit so that everything falls into the same picture."

Lance Cochrane 6550 'Leviathan'

Conclusion - So, here is my advice if you want to pursue a custom amp. Find an experienced builder who has a portfolio building the type of amplifier you want, discuss your system with them, get their recommendations, provide a budget for the construction, and let them do the rest. If you are scared, wait for one of their creations to come up used at a reasonable price and try that first before commissioning something. The most important thing is that final product satisfies, and no amount of obsession, changing your mind or investing in more boutique audiophile-approved parts will guarantee that. Trust your builder!

HiFi Basics I: The Flow of Music - Overview

HiFi Basics I: The Flow of Music - Overview
Talk Tube: Tube vs SS, Triode vs Pentode, SE vs PP, Direct vs Indirect Heated


Prologue
Some time ago I decided to start my first HiFi Basics article with how our hifi gears enhance (or just as often impede) the flow of music. As I took time to formulate, a visit to old friend WSS snapped everything into focus and showed the way. So you may be interested to read about the time I shared with WSS (here).

In this (rambling) article I shall touch upon some of my deepest beliefs, which in future articles I shall expound in greater detail. However, if your inclination is like mine, I do think you shall find some useful audio tips here.

• What is the Most Important Thing in HiFi? Most people get their notion of what is important in HiFi through "magazines" (first paper, now the web). But magazines differ in many respects. Some combine subjective listening with measurement (Stereophile, HiFi News), others just subjective (TAS; and almost all web magazines) (I must say my sympathy lies with the former). All writers write in some way about the flow of music, but not before they expend huge efforts on delineating the various merits (power, definition, soundstage, imaging etc) of the item at hand. This is completely wrong. If the pulse of music, its flow, is not right, nothing else is of importance. Unfortunately, in my experience, much of modern HiFi, most highly praised, belong to this category of mediocrity. Among the worst perpetrators of modern HiFi writing is the Taiwanese magazine 音響論壇, which now gives almost every gear it reviews 9 to 10/10 in all of its 10 HiFi Parameters 音響十要. Its argument is that modern standard is much higher than in the past; while this may be true from a technical standpoint, listening tells a completely different story

• Pace, Rhythm and Timing (PRaT) The UK writers invented this, and they have a good point. Flat Earth people, narrow as they can be, also get this right. I am acutely sensitive to this, but I am aware most audiophiles in HK are not. If music does not have good rhythm and pace, it does not flow well, then all other hifi parameters just do not matter. Music must be involving.

• Tube vs Solid State In general, tube gears are superior to solid state devices. Best are vintage ones in good electrical condition, Western Electric being the Epitome (my WE experiences here and here). This is especially so when it comes to the flow of music (yet there are times where the opposite may be true, like when it comes to certain speakers, usually inefficient ones, ss gears may gain competitive advantage). It is not just a matter of tube, as many modern tube gears are as bad as their ss counterparts in their lack of fluency. The take-home message here is: with transformers or tubes, vintage is usually superior to current production. I don't quite understand why the term "liquidity" is used to describe the sound of tubes - in my experience, the best tube designs have a clear and lucid sound.

• Triode Superiority I believe Triode, especially direct-heated ones, is generally superior to tetrodes/pentodes (in both musicality and transparency). This is true whether it is used in Single-Ended (SE) or Push-Pull (PP) configuration. Even pentodes strapped as triodes usually sound better - there are no better examples than Audio Research's old Classic series amps (Classic 30 /60/120/150), imho the best amps they have made.

• SE vs PP First, SET amps mandate high-efficiency loudspeakers - many SET detractors simply used the wrong equipment (like LS3/5A) to make up their impression. Properly set up, a good SET amp has a tactile presence (sense of the live event) and musical fluency superior to a PP amp. But there are rare exceptions - WE PP amps are superior to any SET I have heard (I have yet to hear the real WE91 - clones need not apply).

• Directly vs Indirectly Heated In my (considerable) experience with SE amps, the directly heated single-ended triode (SEDHT) design has the best performance. An SE amp using triode-strapped pentode (usually indirectly heated, like EL34) is simply second-class in comparison. My very first SE amp was actually not directly heated. It was the Audion Stirling (EL34). I then got the same company's similarly structured Silver Night (300B). There was no comparison and I immediately sold the Stirling. Within this category, I believe the lower-powered EL84/6BQ5 (a superior pentode) fares the best (I have used Welborne Labs and Almarro), though still well short of SEDHT. When it comes to Rectifiers, I also always prefer Directly Heated (like 5U4, not to mention WE 274A/B) to indirectly heated ones (like 5AR4/GZ34/U52 etc). All Directly heated tubes have better presence than Indirectly Heated ones.

• Source - Analog vs Digital Nothing epitomizes the spirit of this discussion more than this point. Analog (vinyl or reel-to-reel) simply delivers the flow of music better, period. This best illustrates that, despite claims of whatever superiority, digital is seriously flawed. , and that is why you should never believe people who trumpet each advance of Computer Music (Computer as Server, CAS). Digital can be competent, but never spend too much money on it. Our humble Sony DVP-PR50P tried at WSS' place (see link at top) provides more magic than many a more expensive digital source. Art Dudley, of Stereophile, opines that the mechanical aspect of vinyl replay somehow is superior to digital number crunching, and I agree with him. This may not be new, as many a Heifetz (legendary violinist) fan who have heard him live swear that his 78's played on a gramophone (mechanical) is more truthful than playback through any subsequent media (be it remastered LP, CD or CAS). I have one of these antiquities, and I do agree that my Andre Segovia 78 (guitar) had a special allure even the LP misses. As for Reel-to-Reel, which is how most of the immortal performances are recorded, read my articles here.

• Loudspeakers Few would deny the importance of the transducer. But which type is the best? There are no best, but I believe a well constructed horn system (like Klipsch, see my overview here) is hard to beat. However, horns by nature like real estate, and not everyone can afford such "luxuries". I am also partial to Full Range Speakers, select traditional 3-ways and First-Order Crossovers. For me, loudspeakers must be relatively easy to drive, as this makes less demands on electronics. Many modern loudspeakers simply fail this. Efficient loudspeakers may not be perfect, but they are usually more musical.

• Preamplifier To me, this is one of the most important link in the chain. With few exceptions, Passive Preamps fail to inspire me. Also, a good tube preamplifier is mandatory - even with ss amps. No solid state preamplifier has ever excited me.

• Amplifiers As a rule, the lower the power, the better the amplifier sounds, and this is true for both tube and ss amps. This is one good reason to avoid inefficient speakers. Simple designs that have stood the test of time, like those in most tube amps, have a better chance of sounding good. Think of SET amps: one reason they sound good is because the circuit cannot be simpler.

• Good Solid State Gears Although in absolute terms rather short of the achievement of tube, ss gears can be quite musically satisfying. Humble examples are now-vintage UK integrated amps (here) and the Micromega and Naim gears I have written about (here), and they do their tricks in different ways that are difficult for words to describe. I shall write more on this subject in future articles. As a rule, the more high-powered or expensive the ss gear, the more you should beware.

• Cables Most HiFi cables, beside being ridiculously expensive, are highly colored, more likely to ruin your system rather than enhance it. I use exclusively highly affordable professional cables (my favorite being Gotham). Also, solid core cables, especially those of higher gauge, are more colored than stranded cables. Think professional interconnects, which aim at neutrality and never employ solid core.

• Tweaks When it comes to tweaking, there are plenty of HiFi lores (and stores) but, I tell you, most dampen and tone down the system's energy. This is because there are just too many equipment and digitally recorded music out there that are simply non-musical, in dire need of toning down. What you need is equipment that performs well as soon as you plonk it down, equipment that needs no excuse. Often enough, equipment are less than inspiring, and you should not make up excuses for them.

This can go on forever, but I shall end it here, with many more articles to come.