Mains filters? and NSC AMPs

[The Dark force of dance]

Y-ellow Y-all.
	Ok. I can see the error of my ways. Actually it was only a stab in the
dark. I've put the whole thing together without any mains filtering because
it was going to be more trouble than it was worth.

But just for succinctness. The reason I was asking was not to protect the
transformer. Rather to protect the rectifier, smoothing caps and the power
amps themselves. The primary of the transformer puts out 60VAC centre
taped. This ends up being 84 volts DC or there abouts. I have dumped this
through a string of diodes so what reaches the amp ends up being 78 volts.
The problem being that the Amps have an absolute maximum rating of 84 volts
with signal applied. So the question is if line-spikes would blow the amps up.

But just to add a little insurance I have placed an extra set of smoothing
caps between each diode pair. This, with any luck will help.

BUT THE BIG NEWS IS IT WORKS!

And it kicks serious ass. (I am of course speaking here of donkeys in case
the censors are watching. I didn't mean to imply that it kicked anyone up
the arse hole or in any other way sank the slipper.)

It's made from a couple of NSC overture series power amp chips. Now as Paul
PA would attest, we've never had too much luck with NSC amp chips but these
big brutes do indeed sink the slipper. Especially compared to my previous
amp. It's actually quite amazing the difference. I have had to go through
and do the white noise test again to set the EQ. But it was worth it.

OK so I blew the fuses the first time I turned it up but 3 amp fuses seem
to do the trick. The amps have thermal, overvoltage and every-thing-else
cut outs built in so I'm not too worried. And the heat sink they are
attached to, the afore mentioned beryllium oxide dosed one, (There goes
that censor again) is very much on the over-kill side of cool.

I'll see about doing something about throwing this up as a project on my
web site if anyone's interested. I am very much impressed with my new toy I
have to say. Mind you my neighbors are already complaining. :(

Thanks again y'all.

Be absolutely Icebox.

 _ __        _                              
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