FirstWatt J2

[Magura]

I opened a thread in the GB section, as some of the SS guys, may not see it here.

http://www.diyaudio.com/forums/showt...10#post1929210


Magura

[tryonziess]

Magura,
I have seen the gb thread and was wondering if anyone was working on a pcb for the project. I have 10 loveltechs stashed away so this is a good thing you are working on.
Tad

[Magura]

Originally Posted by tryonziess

Magura,
I have seen the gb thread and was wondering if anyone was working on a pcb for the project. I have 10 loveltechs stashed away so this is a good thing you are working on.
Tad

Try reading this thread. It's not that many pages, and it will answer your questions.


Magura

[Zen Mod]

Originally Posted by Magura

Try reading this thread. It's not that many pages, and it will answer your questions.


Magura

I already polluted your GB thread .....

assuming that amp is nothing else than augmented Aleph J input stage , with SRPP output stage - matching of output jfets between channels isn't necessary , and even matching of two output jfets in one channel isn't so critical

but - as I wrote there - ask Papa directly ;

his answer will save you at least 50% of matching efforts ( considering that spoiled kids are already talkin' about matched quads )

[Magura]

Originally Posted by Zen Mod

his answer will save you at least 50% of matching efforts ( considering that spoiled kids are already talkin' about matched quads )

Well, let's see, I doubt that it will save me much effort....I also don't have a problem with a bit of matching, as I would be surprised if this hits 300 pcs.

Matching 300 fets is no big deal. It takes a couple of afternoons, and a few cups of coffee, which Mrs. Magura will happily supply to the cause



Magura

[Blues]

my first thread in years and just over a weekend and it's already 5 pages...

Morten, I'm interested in your GB the jfets being TO-247s...

Mr. Pass, are the Lovoltechs even an option for the "other" output jfet (CCS)? Might be useful to some who have a stash of those...and cheaper.

[Zen Mod]

Originally Posted by Blues

.......

Mr. Pass, are the Lovoltechs even an option for the "other" output jfet (CCS)? Might be useful to some who have a stash of those...and cheaper.

let me chip in ..... even if my hair still isn't Papa Gandalf like .......

being SRPP output stage - that means Shunt Regulated Push Pull , where CCS part of totem pole is modulated ..... sort of ....

that means - there isn't exactly needed to have identical lower and upper half , but it's certainly more practical to have them identical



just think about xconductance .....

edit :

pic just for you :

[R-K Rønningstad]

Originally Posted by mos57

This morning i have called an italian distributor for Semisouth devices.
Hi tell me that now they are going to sell Power jFet with 100 mOhm SJEP120R100 type, that is a little big (17A vs.15A) (i think this is also ok).
They send me a quotation for 10 pieces.
Prices is 35 Euros each plus shipping charge from Usa (about 50-60 Eu).

Francesco.

That's not o bad compared to old Sony VFETs on ebay? Even though those might be n-channel and p-channel.

Rolv-Karsten

[Zen Mod]

boyz

what's fuss ?

in few months Papa will find new Holly Grail for us ...... so semisouths will be redundant

[mos57]

Originally Posted by R-K Rønningstad

That's not o bad compared to old Sony VFETs on ebay? Even though those might be n-channel and p-channel.

Rolv-Karsten

Yes, at the last, but Nos Vfet are as a meteor today.
Also i have received vfet from ebayer one week ago and will try its next days in two stage single ended amp (first stage with 2sk79 ).
I like to find any devices that i think should have a good sound quality.
However i think V-fets are a quite different from these sic-jfets.
So i would value their global impact and sonic signature above all.

Francesco.