Sony vFET Illustrated build guide

I finally found the time to finish my Sony push-pull amp, completing the VFET 'triple crown' :D (CD single-ended, CS single-ended, CD push-pull). Certainly you could argue that I should add a CS complimentary amp to that list, maybe a circlotron too... but three seems like a good stopping point, and it works with my analogy :)

What a fantastic amp!! It went together without a hitch, thanks largely to this build guide and Nelson's documentation. I'm still waiting on some little PCBs I made for the hockey puck bridge rectifiers I'm using, but I'm calling this one 'done'.

A perfect summer-time amp, and it easily gives my other amps a run for their money. Probably the quietest amp I've built too.

A big thanks to:

Dennis Hui. Such an amazing guy, Dennis is the reason I was able to build this amp. He supplied me with the P-channel VFETs I was missing, the convenient t-brackets for transistor mounting, and plenty of encouragement. Thanks again, Dennis – your kindness and gratitude are so, so appreciated!

Nelson for this superb design, your continued support, and your endless generosity

Randy Thatcher for these great PSU boards. Work like glue :)

Jim and crew for the great build guide and documentation.

ZM for being ZM. I blame you! :D

DIYaudio is such an amazing place and full of so many amazing people. I'm continuously humbled and inspired by the people in this hobby. Thank you!

:worship:

Codyt.

Late to the party is praising you, :) but that's a sweet looking build.

Enjoy!
 
Very true. It’s kinda like a ‘greatest hits’ of semi’s… K170/J74; K2013/J313; IRFP240/9240; K82/J28

:sax: … a few of my favorite things… :sax: :D


Love the line about the greatest hits!

Love my two pair Vfet amps. In daily use since I built them. Codyt I dont know whether you have done a FFT on them, but a bit of change in bias up or down can change the signature to suit the rest of the system.
Using a tube preamp in front of it really brings out the magic.

nash
 
Member
Joined 2019
Paid Member
Love the line about the greatest hits!

Love my two pair Vfet amps. In daily use since I built them. Codyt I dont know whether you have done a FFT on them, but a bit of change in bias up or down can change the signature to suit the rest of the system.
Using a tube preamp in front of it really brings out the magic.

nash

My initial FFT correlates well to my tastes, though I do look forward to playing with parameters a bit. Great to know you’ve had good success in doing so!
 
Member
Joined 2002
Paid Member
File this under 'better late than never', I was motivated to finally finish my amp after seeing Cody's beautiful construction . I had some chassis issues in the long course of this build. (The first chassis has a warped heat sink, the second was too narrow and finally the third barely worked.)

I have only tried this with test speakers but so far so good.

Thank you Papa for the wonderful project, Jim for the helpful build guide, and Cody and the Mighty Zen Mod for motivations and fun discussions.
 

Attachments

  • IMG_20211226_163229~2.jpg
    IMG_20211226_163229~2.jpg
    535.9 KB · Views: 196
My everyday amp! Serious reference, haven't heard anything better yet!

My voltages are slightly on the high side (+/- 30Vdc, a bit due to the active rectification it has today, but I don't dare to touch it, as it sounds perfect the way it is. In my small box, it does need a babysitter during summer. :)

20190706_221957.jpg