BOSOZ balanced pre - for novice - questions

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Main board - test

Hallo,
after PSU I'am building the main board. I would test it as Nelson Pass says




On the main board the Drain (case) of Q1 and Q2 should be about +30


volts. The Gates of Q1 and Q2 should be at ground. The Source pins


of Q1 and Q2 should be about -3.5 volts or so.


First question:
may I test main board without connect potentiometer? I use input potentiometer, no output potentiometer, fixed resistor for gain (P5).


Second question:
Shall I measure voltage of Q1 and Q2 referring to ground?


Sorry for my stupid questions
Thank you
 
I have a couple of BOSOZ preamps...

For a new system, I bought what I thought was a pair of stuffed BOSOZ boards and I see that the boards are actually the XCCS BOSOZ boards.

I have hooked them up to 60v rails and checking voltages, I notice that the Drain to ground voltage on the IRF 610's is not 30 volts, but 5 volts on one and 10 volts on another and so on.

My question is: On a proper XCCS BOSOZ, shouldn't drain to ground voltages be around 30 volts as would be on a regular BOSOZ?? I am thinking these boards are incorrectly stuffed...
 
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