SemiSouth power Jfets .......... FW J2

[generg]

Hi tea-bag,It is incredible to hear your continuing story of pity with J2 ......You must hear this amp, it is lovely, especially in voices. Not totally exact, but the most charming boy I have heard.......I wrote already that BJ2 is a bit more dur and the other version is a bit more moll. It's only a matter of taste or mood.....And I prefer J2 clearly to F5.It seems to be a long time since Nelson gives free the circuit........

[CeeVee]

Hi guys,My BJ2 is finished, had to adjust a couple of resistors to get alignment but it has run for 3 days and been realigned, stability temp and alignments are fine, it's running at 2A bias, rail voltage 25,4 V Sound is ....................gorgeous, comparing to my F5 it seems to have more definition and "attack" , very well defined bass....voices have been praised by many....i agree, and it's very easy on the ears, no hints of tyring effects. here are some pictures as promised with a huge thank you to mighty ZM... :respect: :guitarplayer:

[CeeVee]

....innards....

[stein]

[Zen Mod]

Fugly!

[CeeVee]

I tried to make the case do justice to your fantastic work.....but i guess i was a little bit too eager to hear it .......

I was just listening to IZ singing " over the rainbow" ............oh boy , i'm overwhelmed !

[Zen Mod]

priceless ! give us more porn , please .......

[Zen Mod]

........

I was just listening to IZ singing " over the rainbow" ............oh boy , i'm overwhelmed !

....

http://www.diyaudio.com/forums/pass-labs/135674-pass-pub-high-end-off-topic-thread-155.html#post2657857

[CeeVee]

Just so you know what i have to play with the BJ2, from left to right; The Orions 3.4 ( last version with original woofers ), obviously i don't have enough BJ2s to play them with but remain my reference system with an ATI amp ( 12x 60 W ).The little passive speakers i have at the moment to test with, Mordant short 89dB, not in the league of F5 and BJ2 but boy do they sound good !My developing Shiga Clone...plays great but not up to the Shanling on it's right yet, behind that is a Bufallo DAC.Shanling with new discreet IVs, developed with the help of your's trully....ZM, my reference CD player.BJ2 ofcourse and the Orions' Analog processor.......

[CeeVee]

More BJ2 Porn....

[CeeVee]

more

[CeeVee]

innards back...

[Zen Mod]

these pcbs are more sexy than mine maybe just second pair of black ones , sent to AR2 , is more wakoo looking ( btw you have 2 posts without pics)

[CeeVee]

( btw you have 2 posts without pics)

...no all have pics.

[Zen Mod]

OK - now I see pics ; is it possible to see entire amp from top , with few words about PSU ? now I see just one possible area of improvement - making it dual mono ;

[CeeVee]

Here you go...

[Zen Mod]

plenty of space , for additional Donut , caps pcb and diodes then you'll have even more holographic atmosphere , also more authoritative lower register btw - caps are ?

[CeeVee]

The PSU is pass standard 4x15u TSHA each channel with CL60 from ground to chassis and another one in series with primary. dead quiet.Transformer is Toroidy 400VA , 2 18V secondaries. You think going double mono is better ?....2 300VA transformers ? would really appreciate your input on this, wouldn't mind going for a all tricked out PSU for it, if it gets any better i'm making a pedestal for it .....

[Zen Mod]

just double existing one ; so one dedicated PSU per channel try to find place for motor-run bypass caps ( as finals in PSU) my preferred are ICAR 50-70uF ones ; considering that you'll have trouble with space - use 30uF ones

[CeeVee]

just double existing one ; so one dedicated PSU per channel try to find place for motor-run bypass caps ( as finals in PSU) my preferred are ICAR 50-70uF ones ; considering that you'll have trouble with space - use 30uF ones

Great, i'll look for the motor run caps locally, ICAR is difficult to get i think....but i'll look around...thanks again ZM .I'll make another bottom plate and optimize layout for double mono, you bet I'll fit the motor run caps.....:-)

[CeeVee]

Master ZM, Here is the Beast......Two toroydi 400VA, double MUR 3060 BRIDGES, 120UF TSFHAs per rail/channel bypassed by 40uF DUCATI caps ....aiaiaiaiaiaiaiaiai ........ some building pics:

[CeeVee]

the double bridges...and a DUCATI....hope this one performs better then Vale's........