Sony vFET Amplifier Part 2

[luvdunhill]

.. and with feedback

 

[luvdunhill]

@luvdunhill



I suggest that you create a separate GB thread instead of updating here, most of us waiting for Papa update.



Just my ¢0.02

Done. http://www.diyaudio.com/forums/swap-meet/291234-fs-nelson-pass-vfet2-front-end-pcbs.html

Moving on this point back to VFET1 FE, so I won't be back here for a bit 🙂

 

[Nelson Pass]

The 400 pair of Sony 2SK82 2SJ28 have been tested and sorted in order
of Vgs. I understand the brackets are due in shortly, and 6L6 is working
on a pair for a DIY build guide.

😎

 

[Zen Mod]

Beast with Thousand JFets , Vol. 2

 

[wdecho]

The news is getting better and better.

 

[nicoch58]

great work !

 

[Soundhappy]

The 400 pair of Sony 2SK82 2SJ28 have been tested and sorted in order
of Vgs. I understand the brackets are due in shortly, and 6L6 is working
on a pair for a DIY build guide.

😎

Incredible Mr Pass Fantastic work !!!
That good reason to be very happy diyer.
Thanks Mr Pass , 6L6 and Diy Audio Team

 

[NihonJR06]

Fantastic ....🙂
Thanks Pass sensei and all DIY audio team
Yeah ...

 

[2 picoDumbs]

Thank you everyone

 

[aoc]

Can't wait

 

[Bones13]

Woo hoo, another part of the puzzle is revealed. Getting close now.

200 kits max, hope I am quick enough on the draw.

 

[wengtech]

Hello everyone... glad to hear that good news from Mr.pass.

Btw, can I use this setup to test other kind of mosfet such as k135 j50?
Any modification needed?

Thanks.

 

[platon.rado]

Good news,Thank you Pass

 

[rideht]

So excited 😀

 

[2 picoDumbs]

Hello everyone... glad to hear that good news from Mr.pass.

Btw, can I use this setup to test other kind of mosfet such as k135 j50?
Any modification needed?

Thanks.

No.
They will need to be depletion mode mosfets.

You could however just build the front end gain stages and make your own biasing circuit for the devices you want to try.

 

[WBS]

Beast with Thousand JFets , Vol. 2

Or it could be Beauty, with 800 VFets!

😀

 

[WalterW]

The 400 pair of Sony 2SK82 2SJ28 have been tested and sorted in order
of Vgs. I understand the brackets are due in shortly, and 6L6 is working
on a pair for a DIY build guide.

😎

Is the marking on the VFET's the Vgs at 0.5 Ampere?

 

[Nelson Pass]

You can just reverse the bias polarity - +19 for the N channel, -19 for the P

😎

 

[2 picoDumbs]

You can just reverse the bias polarity - +19 for the N channel, -19 for the P

😎

Good thinking Papa.
If using to247 lateral mosfets my brain is sought of visualising running wires from the gate pads on the pcb to the opposite polarity mosfet.
However Vgs is much lower on lateral mosfets ie less than the 2.5V reference on tl431, so that would need to be swapped for maybe adjustable lm385 with 1.25V reference, I'm guessing.

The second question would be is running the modulated regulated cascode irfp devices still beneficial with lateral mosfets? I guess it would be.

 

[nagini262]

Look very nice but very thick, this is good or bad for VFET P2?🙄