Sony VFET Amplifier Part 2

[wdecho]

I am definitely in for kit with matched dual pairs. What respectable Passaholic would not want to build a SIT amp considered by experts to be the best thing going in SS for an amplifier?

 

[Luke]

I would be interested in a kit for a matched dual pairs too. Cost may be a consideration, our dollar is crashing against green back.

 

[Dennis Hui]

I would be interested in a kit for a matched dual pairs too. Cost may be a consideration, our dollar is crashing against green back.

Alas the same applies to us in Canada.

Dennis

 

[Dennis Hui]

I wonder if Mr. Pass can share with us more information on the performance with
a single pair of VFets per channel, since those kits will likely be more readily
available.

Thanks,
Dennis

 

[res07njc]

hear hear, as owning two pairs myself for the intention of not matching the devices I'd also be interested in a few more words on the subject.

 

[drjbf1]

I have parts, but think I will build the single pair version. In the event of a failure either during construction or later on, the amp will be easily fixable.

 

[JPeitzman]

I would 100% be in for a kit!!! Sign an affidavit, sure. Photographic proof of the build, no problem. Promise of delivery of my first born, I can do that!

 

[Soundhappy]

Can anyone recommend a good source for the IRFs in TO-3 to match the Sonys? Thanks

You can try this links for TO-3 case IRF's :

irf240 Stock and Price by Distributor

IRF9240 Stock and Price by Distributor

Other package IRFP's 240/ 9240 do the job as well.
Yes IRF TO-3 look nice with vfet´s together.

Greetings

 

[drjbf1]

Thanks Christophe.

 

[lhquam]

I have noticed all of the FirstWatt designs use the jfet input gate-stopper and input load resistor shown as Option A below. Why is this done vs. Option B which does not attenuate the input level?

 

[rayma]

I have noticed all of the FirstWatt designs use the jfet input gate-stopper and input load resistor
shown as Option A below. Why is this done vs. Option B which does not attenuate the input level?

The F6 uses option B. I prefer that one as well, since it minimizes the connections and parasitics at the sensitive gate.

 

[Soundhappy]

LSK buffer for Sony CSX1 vfet amp have the same
schematic version B

 

[Nelson Pass]

I have noticed all of the FirstWatt designs use the jfet input gate-stopper and input load resistor shown as Option A below. Why is this done vs. Option B which does not attenuate the input level?

When I laid the boards out, sometimes it works out with the resistor to
ground in front, sometimes after the input, probably because it's convenient
and really doesn't matter.

Then I go back and change the schematic.

I can do that.

 

[Luke]

what is CSX1?

 

[Soundhappy]

what is CSX1?

http://www.firstwatt.com/pdf/art_sony_vfet_pt1.pdf

 

[Luke]

thanks soundhappy

 

[Zen Mod]

When I laid the boards out, sometimes it works out with the resistor to
ground in front, sometimes after the input, probably because it's convenient
and really doesn't matter.

Then I go back and change the schematic.

I can do that.

he's doing that sort of things to me ....... all the time

that's probably good thing , laughing is extending Papa's life expectancy

 

[Rodeodave]

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?

According to the vendor they are 2SK82 JA-33 grade.

 

[Luke]

Hi Rodeodave, any idea what JA-33 mean?

 

[dady]

@Luke:
Is the Bath of production.