Sony vFET Amplifier Part 2

[Zen Mod]

something as this .........
from some reason I can't upload any pic in this moment , so I just put it in my DB folder

upload is working now , file deleted from DB , attached here

desired Iq set as 0V65/Rs , where Rs is value of source resistance in CCS

as drawn , 0V65/0R5 ~1A3

 

[WalterW]

That said, I would still like to see some of these PP circuits built.

Yes sir!
I have four pairs within 0.2 V matched VFETs, so I'm certainly going to build one of these PP VFET amps.

 

[Michael Rothacher]

I think I have enough for a single-pair output version.

Who's gonna do the PCB? 🙂

If I attempted this one point-to-point, it would look like a Jim Williams sculpture.

 

[Dennis Hui]

I think I have enough for a single-pair output version.

Who's gonna do the PCB? 🙂

If I attempted this one point-to-point, it would look like a Jim Williams sculpture.

I think I'm in the same situation.

Would it make sense to make separate it into two PCBs? The front-end
probably will make a good preamp as well (like the BA-3). And folks
can play with variations on the follower...

Dennis

 

[CeeVee]

One option is to make a single-ended SIT amplifier using a P channel follower
and biased by a constant current source.

Very easy to do.

I certainly can deliver that and so you guys should consider buying those up.

That said, I would still like to see some of these PP circuits built.

...you will if i have anything to say about it,

I have 8 pairs so if i have any luck i should get 4 sensibly matched ones.


i intend to make this a tribute amp...to your generosity of course and to a time when brilliant minds worked to produce great audio amps....and not just "good enough" as SL put's it.


😎

 

[WBS]

Oh well...

I found this thread yesterday, got all frothed in the mouth and tried to order some pairs, too late.

I ordered some 2SJ28 instead, anticipating a design that might provide some of the magic described in your article. One can only hope!

 

[Nelson Pass]

We will probably address this a couple of ways, but it will take a little time.

 

[bwaslo]

These people show some in stock
Aliexpress.com : Buy SONY 2SK82 V FET from Reliable fet transistors suppliers on Eternal HONG's store | Alibaba Group

No idea if they're authentic, though. Any gamblers here?

 

[MASantos]

Awesome article as always!!

I really like the front end! It's sort of a BA-3 FE with local feedback and regulation.

Could it be used to drive a BA3 output stage?

10 pages and still no balanced schematic? 😀

 

[Zen Mod]

.....
10 pages and still no balanced schematic? 😀

considering how's that trivial , I assume that you're joking

 

[MASantos]

considering how's that trivial , I assume that you're joking

joking yes!! 😀

 

[Vix]

I just downloaded ZM's initial version of this amp. One pic only. Will read the real one tomorrow, but this one isnt't bad either 🙂 Thanks! 😉

 

[drjbf1]

I think I'm in the same situation.

Would it make sense to make separate it into two PCBs? The front-end
probably will make a good preamp as well (like the BA-3). And folks
can play with variations on the follower...

Dennis

This is a good idea.

 

[Bones13]

I had purchased 2 pairs for the CX1 build, and am about to start that one. I am following Michael's Hangout thread, and bought and returned some 2SK182ES parts that were not good. I ordered another 4 pair of the 2SJ28 and 2SK82 for what I was thinking would be a 2SK82 l'amp and the CX2 (assuming 2 pair for CX2 like the CX1 is).

Now I am guessing I need to get MR's frankentracer built, and see if I can match up some of my pairs for the CX2, and use the less matched ones for the CX1.

If matches don't work, I can look at whatever else NP can cook up, he sounds dissappointed that his article came out, just as the VFet source dries up.

Thanks for the CX2 Nelson!

 

[Soundhappy]

Who's gonna do the PCB? 🙂

If I attempted this one point-to-point, it would look like a Jim Williams sculpture.

Yes Sir Pass pcb layout is much better & useful diy audio ART .
Always made with logic for great heat dissipation 🙂

Jim Williams: The light side and classic electronics art sculptures | EDN

 

[gadut]

????

Note that not every country can shop with TB, and many TB sellers cannot communicate with English (not sure about this one). I bought some Yamaha 2SK76/SJ26 from this shop before, and as far as I can tell they are authentic.

I have never had any interest on PP design, but this beast seems different. I'm so lucky that i have a colleague worker who is located in china and help me to buy 4pairs (is it enough?), and hopefully they are genuine. I already have 3pairs of 2SK82 from acronman intended for sit l'amp

 

[lhquam]

Why the hell can't an American company produce those fets? If Linear Systems can do 2sk170s and 2sj74s, why not 2sk82s and 2sj28s? Oh, BTW, is Linear Systems still an American company? 😡

 

[gaborbela]

These people show some in stock
Aliexpress.com : Buy SONY 2SK82 V FET from Reliable fet transistors suppliers on Eternal HONG's store | Alibaba Group

No idea if they're authentic, though. Any gamblers here?

I think these is the company I wrote, asked more pictures (from the actual items ) unfortunately I never get any answer (yet)
Based on the picture they posted look authentic but can be the usually Chinese method (trick) post original pictures and ship counter faith items.

 

[gaborbela]

I do have two pair for these project but I would be also interested on Mr. Pass Class A project.
That two pair useless for these project.
I post that amp circuit here, in case that will be a problem please feel free to remove it.🙂
Thank you
I do not want to hijack the forum!
Greetings

 

[nopants]

Why the hell can't an American company produce those fets? If Linear Systems can do 2sk170s and 2sj74s, why not 2sk82s and 2sj28s? Oh, BTW, is Linear Systems still an American company? 😡

probably because the only market is people like us. I doubt they'd make anything