Krazy JFET-cascoded Pass BOSOZ

[Zen Mod]

btw-which Sen model are that ugly cans?

 

[jh6you]

HD595 . . . (tried HD600, too) . . .

The headphone amp is not diy . . .
Stainless steel box made by Tsinghua university R&D in China . . .

Have to spend most time on my profession (stress gain) . . .
and little on listening to music (stress relief) . . .
and hardly on diyAudio (often headache) . . .

Err . . . by the way,
have a plan to make one headphone amp shortly . . .
but, using JFET or Mosfet . . .

Regards
jh

 

[jh6you]

Hah . . . !

Krazy is picky . . . like someone around me . . .
I changed input cap from Ixel 1uF p.p. 1% to CHEAP Taiwanese MXE p.p. 5% . . .

Distinctively better . . .

Regards
jh

 

[Zen Mod]

Hah . . . !

Krazy is picky . . . like someone around me . . .
I changed input cap from Ixel 1uF p.p. 1% to CHEAP Taiwanese MXE p.p. 5% . . .

Distinctively better . . .

Regards
jh

maybe just is that cheap taiwanese cap is better than Ixel.....

 

[Zen Mod]

tell me specs of your mains xformer
I need that for another PSU proposal

 

[jh6you]

Ulveco 2 x 30V 50VA

tks

jh

 

[Zen Mod]

have you some ~12V/~10VA xformer ,to stack secondaries in series?

 

[jh6you]

No . . . but, just go ahead please.
I can easily order any size . . .

jh

 

[Zen Mod]

just for starters

 

[jh6you]

Thanks, Choky, very much.

Ha . . . number of components few enuf for me . . . I will study this before I give a shot . . .

. . .

Regards
jh

 

[Zen Mod]

Thanks, Choky, very much.

Ha . . . number of components few enuf for me . . . I will study this before I give a shot . . .

. . .

Regards
jh

patience brings confidence........



sometimes justified,sometimes not

 

[jh6you]

Music through Krazy BOSOZ (& F1 & J-low) gives me . . . bla bla bla . . .

O . . . I did not mention one thing.
Krazy is best fit with F1 (subjectively) when I have the Aleph ac current gain of 0% . . .

If any diyer has the original F1, and unless drives it with tooboo pre, try Krazy. You will be getting crazy on music . . .

Enjoy!!!

jh

 

[jh6you]

Hi Nelson

Will this variation improve . . ?

Regards
jh

 

[JoshK]

This project looks interesting, but I am wondering how hard it is to change the gain to 0-6db, or whether it would be more beneficial to start over. I am really new to this stuff.

Has this already been done elsewhere? Then we also have these new lovoltech jfets to use.

 

[Nelson Pass]

Will this variation improve . . ?

It looks very nice to me.

 

[apassgear]

Hi Nelson

Will this variation improve . . ?

Regards

Nice circuit JH.

What I don't understand is the use of input cap. Could you explain please?

 

[jh6you]

. . . the use of input cap.

It's to block DC coming through the ref B point.

For info:
Ref A = 60V DC (from a simple PSU)
Ref B = 9V DC (from the same PSU)

We can control the gain easily. If the JFET source R goes up, the gain goes down.

This technically works well . . .
Nevertheless, I am trying to find a replacement of J310 because J310 has very narrow working area. Otherwise, the sound is subjectively great . . .

Regards
jh

 

[apassgear]

OK, I got the point. I understood those ref points as ground, didn’t look close enough…

How would it work if you bias it with a 9V battery?

 

[jh6you]

We can get the 9V from everywhere . . .

Rolling Stones coming to Shanghai . . .

jh

 

[JoshK]

Thanks JH...I think I might have to play around with this circuit.