New Age PASS/A40 thoughts

[JJT]

I just found an old set of PCB's for the A40, and decided to
build a new one. I want a single channel, guitar amp.

I'll use an old GMT preamp that is transistor, around 34vts.

I have a +/- 45vt trans at 12 amps, a 19" case, the PCBs are
even already stuffed. I'm thinking of etching new ones to go
with the MosFet mod, and to reduce size for this thought...

I have quite a few CR160 series C/reg diodes, at the values
I find in the '78 sheet...(2 n 6 ma), at 100vts. Should work.

Can I just eliminate (Q11/R9) and (Q3/R7) and (Q4/R10) and
(D1/D2) using these current reg diodes at directed points?

2ma at the D/Pair, and 6 at R15, tied to V-.

Do c/r diodes double in Par or Series? Biggest I have
is 4.7ma, but then again, how high can I go for S & Grins?

I'd guess, as far to the limits of the transistors, and how
close to the wind one wants to sail. How high the moon?

Must I use Tant caps as C2 n C3, I have some 220uf, 50v 5%
non-pol caps. Should I use them..? Any reason NOT to?

Found some 300Watt, 200vt Mosfets and a few ECG 2349/2350
transistors, but want to use the MosFets. At 300watts, 5 amps
can I get by on just ONE per rail..? I'll be driving 16 or 8 ohms.

I can buy 10amp at 200vt Mosfets.

Thanks to anyone who can voice 2 cents about this ranting,
and a double thanks to Mr. Pass for the education.


JJT

 

[MikeW]

I built a MOSFET A-40 a while back. Here is the schematic.