Sony VFET Amps

[Soundhappy]

Edible after sautee with wine?

French don't eat grasshoppers but frogs and
Classic is bread with cheese and little glass of wine with grasshoppers singing at the garden

Back to the topic new article about Sony CES 2014 with Pass Labs inside :

CES 2014 Coverage | Ultra High-End Audio and Home Theater Review

Have fun
🙂

 

[Soundhappy]

Just discovered beauty of vintage transistors

Transistor Museum Construction Projects Point Contact Germanium Western Electric Vintage Historic Semiconductors Photos Alloy Junction Oral History


before we see nano transistor with your dream sound.


Wait patiently if Papa be come back with schematic for Diyers

Greetings
🙂

 

[R-K Rønningstad]

Here's a photo of one just before it went off to CES.

😎

I thought I bought enough VFETs from Acronman, but it seems I am a little short.... Well, I do not need 250 W, I need more time!

 

[Soundhappy]

Acronman is a very reliable supplier IMHO.

I'm in the middle of matching 230 pair of K82 and J28, but of the
KE33 rank. I'm testing for Vgs at 20V Vds and 0.5 and 1 amp,
transconductance and Drain resistance.

It's very tedious.

😎

 

[Soundhappy]

Greetings
🙂

 

[CeeVee]

Greetings
🙂

2SJ28 and 2SK82 🙂

 

[R-K Rønningstad]

Common source or common drain

Mr Pass, I think I understood from the thread that the output stage is configured as a source follower.
One year ago I did some LTspice modelling with Mr. Rothacher's spice models, but with the output as common source. It seemed to work OK enough, but I never came to work out the details, not to speak about actually build something.

/RK

 

[Nelson Pass]

The Sony amplifiers at BAF 2013 were Common Source. The amps shown
at CES were Common Drain.

😎

 

[Zen Mod]

SIT XA250.8

 

[Soundhappy]

Thanks CeeVee
You are absolutly right.
Sorry i be little sleepy sometimes.
This is Vfet complementairy pair 2SJ28 and 2SK82 pdf datasheet link
Best regards
🙂

 

[R-K Rønningstad]

The Sony amplifiers at BAF 2013 were Common Source. The amps shown
at CES were Common Drain.

😎

Thank you!
(I missed that there were some at the BAF2013!)

 

[Soundhappy]

SIT XA250.8

Pass-Sit-1 XA250.8

 

[Soundhappy]

[/ATTACH]

Pass-Sit-1 XA250.8

Pass-Sit-4 XA2850.28

 

[Soundhappy]

Interesting blog pages with links about SIT's V-Fet's with DIY schematics.

???? Oldman's Note: V-FET / VFET / SIT ?????


http://www.geocities.jp/mutsu562000/root/amps1/htm/hp005.htm

SONY 2SK60£¬NEC 2SK70£¬YAMAHA 2SK76£¬SONY 2SK82£¬YAMAHA 2SK98²»ÍêÕûʵ²â - ¡¾µ¨»úÖÆ×÷ÓëÐÀÉÍ¡¿ - ÒôÏìÖйúÂÛ̳¡ª¡ª×¨ÒµÒôÏì¼¼ÊõÉçÇø! - Powered by Discuz! & Audio-audio.Cn

Google translation can be used
Hope you enjoy it
🙂

 

[kasey197]

Hard to see how any of these Japanese circuits play to the advantages of the vfets.

 

[Soundhappy]

2SJ18 CSPP


2SJ18 CSPP Power Amplifier

Maybe inspire you.
Greetings
🙄

 

[kasey197]

Mmmmm much better 😉 maybe I just have a bias for simple circuits

 

[Soundhappy]

Mmmmm much better 😉 maybe I just have a bias for simple circuits

🙂

 

[Soundhappy]

One more with V-fet's amp schematic
🙂

 

[R-K Rønningstad]

Seems like an early eighties input stage, maybe even late seventies. What is it? Who is the designer?