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!