Nice sounding JFET recos...

[Tieftoener]

Hey all,

In Jocko's I-V stage thread, he mentioned that he would use a JFETT follower at the output stage as a buffer....

......but I would add a buffer for a number of reasons. A simple JFET follower works well here.

I'm looking for some suggestions on nice sounding JFETs... got any?

I picked up a couple VHF JFETs at Rat Shack last night to play with something... (the part number escapes me ) but I doubt they're of good caliber. Also picked up a pair of IRF510 mosfets to play with. Thought maybe I'd run them in a cascode configuration...

Again, looking for suggestions on a nice Class A preamp output buffer for Jocko's (and Tschrama's) I-V stages

Thanks -

 

[Fred Dieckmann]

jfet followers

Jocko uses paralleled 2SK170s as follower biased by a BJT current source. I have one of his DACs and a couple of Buffer boards for CD players he designed. I use the Borbely Jfet version of the White cathode follower. McCormack audio uses a complementary 2SK170 2SJ74 pair follower in their buffered passive preamps. They sound very good.

Great jfet circuits:

http://www.borbelyaudio.com/ae599bor.pdf
http://www.borbelyaudio.com/ae699bor.pdf
http://www.borbelyaudio.com/borb502.pdf

http://www.forsselltech.com/schematics/Class A JFet Opamp.PDF


Toshiba Jfet data sheets:

http://katalogi.iele.polsl.gliwice.pl/en/download.php?id=70389
http://katalogi.iele.polsl.gliwice.pl/en/download.php?id=70372


Where to buy Toshiba jfets:

http://www.ceitron.com/
http://www.mcmelectronics.com/

Did I leave anything out?

 

[Tieftoener]

Holy cow! Thanks Fred!

With the PCM63 in my Denon DCM370, PMD100 HDCD Digital filter, the removal of those horrible muting transistors, removal of a really poopy electrolytic cap for DC removal, and the swap of an old JRC opamp with my OPA2134's, I was in total heaven this week while I again reevaluated my entire collection of music. Now, I'll get to do it all over again after making a REAL I-V stage... Muuuuwaaahaaahaahaahaaaaaaaaaaa!!

 

[mlloyd1]

Re: jfet followers

I've seen the NEC (I think ) 2SK163 used a buffer and preamp front end in RIAA and line level commericial equipment. This device is still available cheaply from the places Fred mentions

Unfortunately however, I have yet to find a datasheet for this device. So, I can't say it's better or worse than 2SK170 until I fire 'em up 😉

Fred didn't leave anything out. I've tried some of those circuits over the years and they sound great!

Gee Fred, how much hard drive space DO you have ?🙂

...Did I leave anything out?

 

[prh]

Fred,

Thanks so much for those JFET links!

This is some of the most useful info I've gleaned from the forum.

Much appreciated!

Paul.