Sony vFET Amplifier Part 2

Don't know what you both mean, but this is what I want to build, see picture.
I see it's not a half 40th anniversary but only a third 😀 (with 2 matched VFETS instead of the 6 Nelson used).

So I need 4 pairs of matched 2SK82 and four pairs of matched 2SJ28 for a stereo amp.
I have already 3 reasonably matched pairs of 2SJ28, but these can still be bought by Acronman, so the fourth pair will be possible.
And I had two pairs of 2SK82, and luckily the one and only real 2SK82 of the ten pieces I bought, matches nicely with a 2SK82 I already had🙂🙂
So I now also have three matched pairs of 2SK82.
I only need one extra pair, or even one extra 2SK82 which matches with the VFET's I already have. So if someone has a 2SK82 which matches one of these, you can make me a happy man🙂 :
 

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Dear, you are wasting a lot of vfet in a source follower, anything you use is the same. The key is the symmetry of all the front end. The rest is almost transparent. If you got 2sk60/j28 in enough quantity you have the amp. The dissipation is not much.
 
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Like in the case of WalterW, I too got 4 pieces of 2SK82 from EternalHong on Aliexpress. The printing is distinctly different from the ones I got from Singapore and is also printed upside down from a pin orientation perspective. I am fairly certain that they are not the genuine Sony VFETs.

Cheers.
 
Hi,

Did some measurements of the VFETS I have using NP's suggested method in this thread. As suggested by him, I measured VGS for 0.5V across 1 Ohm resistor on the drain pin. I think I have few near matches, but not close. Can members kindly comment if any of the pairs is a viable pair in the VFET2 circuit?

I will hazard a guess that some of the gurus on this forum can make them behave similar by altering the VGS closer to the other matched DUT at a required current rating like 1A, but it is way beyond my capability.

2SK82 (VGS)

Pair 1: 7.52V and 7.81V
Pair 2: 8.96V and 8.76V
Pair 3: 7.92V and 8.25V

2SJ28 (VGS):

Pair 1: 10.64V, 10.66V
Pair 2: 6.61V, 6.66V
Pair 3: 8.79V, 8.51V
Pair 4: 6.91V, 7.05V

Regards
 
Pair 1: 7.52V and 7.81V
Pair 2: 8.96V and 8.76V
Pair 3: 7.92V and 8.25V

2SJ28 (VGS):

Pair 1: 10.64V, 10.66V
Pair 2: 6.61V, 6.66V
Pair 3: 8.79V, 8.51V
Pair 4: 6.91V, 7.05V

I would pair the 7.81V 2SK82 (from pair 1) with the 7.92V (from pair 3), then with pair 2 also you have 2 matched 2SK82 pairs that are within 0.2V. Your pair 1 and 2 of 2SJ28 are very nice.

So you're in business to build a part 2 with 2 pairs per channel 🙂