Here’s the 75 Watt V-FET prototype on the bench. More wires than Keith Emerson’s Moog! Edit: Just a few days after I wrote that caption, Keith Emerson passed away. RIP Keith. Thanks for all the music.



Here’s the THD at 1W and 10W πŸ™‚

Here’s the simplified schematic for V-FETRON. There’s a 20 Watt version and a 75 Watt version. I think I’ll give them clever names like: V-FETRON 20, and V-FETRON 75. The 20 Watt amp uses either 2SK82 or 2SJ28. The 75 Watt amp, created for our friend Tim, uses 2SK180. I have a few more transformer types on order to evaluate, then I’ll let you know how I addressed some of the various issues involved. Muhahahaha, more later.


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7 thoughts on “V-FETRON

  1. admin Post author

    You could try it. I probably wouldn’t mess with those devices much without cascodes.

  2. Ernest Dailey

    What about a pair of our little buddy the LD1014d with source resistors of ~ 2ohms running off 12v supplies. for a 7.5 Vetron ? By the way what input transformers did you use ?

  3. Aren

    Well, you’ve inspired a purchase of some V-Fets, so I’ll be keeping an eye on this one πŸ˜‰

  4. admin Post author

    Thank you, Tim. We’re going to have some fun with this one. More info on the way. πŸ™‚

  5. Tim Chan

    Hi Michael,

    Very nice design, (as always from you), looking forward for more details to be released.

    Too bad that there are some disturbances in DIYA which discourage you from posting about the V-FETRON there. Greedy boyz missed your inputs at the PASS forum.


  6. admin Post author

    Hi Esteban. That looks like a nice transformer. I’m sure it would work fine. For the 75 Watt amp, we must address some issues on the input. More on that later.

  7. Esteban Bikic

    Dear Michael, friend, one of my favorites diagrams is the Cyrclotron, I love AtmaSphere, I making one clone of one of them. I planned make the same with, or the 2SK180 either the THF51 I got many. The reason is Iike pushpull, more eficiency and power. I saw you choose previous Cyrclotron for the pass article, that you connect the speaker or the load between the Drains of the FET or VFet in this case. But in the original schemas from Atma and many of other circuits the Speaker is between the Cathodes or de sources.
    The other choices is the transformer, this an excelent solution in transfer and shift the signal without good Bandwide and without any of the problems that caps have. I got many transformers for it since long time. And Also I planned in use the same of the CSX1 I got more of them, cause I like transformers.
    One of my favorites is the LL1539, what you think about it?
    Best Regards my friend

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