F1 Service Manual

Nelson Pass

The one and only
Paid Member
2001-03-29 12:38 am
The draft of the First Watt service manual is posted at


and you have an opportunity to see it and offer corrections
or comments before it goes up officially at FW.

It's a 5.4 M doc file, so some of you dial-up guys might want to
set the time aside for it.


/pass/: just got his wine shipment from David Berkeley, and
has to go now.
Thanks for sharing, NP! A couple of other minor notes:

On p.7, the statement that the drain of Q1 operates at about 3V should instead refer to Q7, I think.

Also, in the amplifier schematic, I believe that R20 should go to the + supply rail, not to the right output terminal as shown.

Several nice touches here, if I may be so bold. I especially like the dual use of thermistors as inrush current limiters and line voltage jumpers.

Nelson Pass

The one and only
Paid Member
2001-03-29 12:38 am
lumanauw said:
There are 2 zeners for protection at input. Somewhere I read that zeners that biased with low current can make noise. Does it make noise here?

The zeners are not in conduction, so they don't make noise.

BTW, thanks everybody, especially Grey for the corrections.
Desmond is posting a pdf file, but it's still huge - I couldn't get
pdfwriter to make it small and still retain the detail on the
board layouts.