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Jerry Jerry is offline
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Default AR3a/AS103a speakers and the Heathkit AR1500 receiver

Peter Wieck wrote on 10/7/2006:

Jerry wrote:
I have the equivalent of a 750 watt amp (@ 4 ohms - 375 watts @ 8

ohms).
Why in heavens name would I want a mere 200 watt amp. That would be

going
backwards.


Jerry:

Pulling the pots from the AR3(a) is about the first thing that should
be done, they were barely functional when-new. So we are 100% agreed
there. But per any of the several web-sites dedicated to these speakers
(Layne, Vintage, et.al.) this gives only about a 3dB gain (assuming
otherwise good pots) over the pots in the max (theoretically
straight-wire) position.


Hmmm, 3db seems low, but could be right. I should have, but didn't measure
before and after. In any event, a 3db reduction in power is equivalant to
cutting the power to the mids/tweeters in HALF. That is, I now send half as
much power to the mids/tweeters and get the same SPL. This equates to a
terriffic gain in headroom and issures clipping in the mid/tweeter amp will
never happen.

Peter, you never told me you removed the pots from your AR-3a's!

You can't do this, Peter, and mainain the proper sound balance UNLESS you
compensate with fixed resistance in the xover. So, Peter, what mod did you
perform upon your 3a's?

And, as to the "equivalent" of a 750 watt amp, _ALL_ I am suggesting is
that unless you have tried the brute-force amp and rejected it as being
unsatisfactory as compared to your present set-up, you REALLY SHOULD
try it. The results may well be revealing. At the very least they will
endorse your present position.


Alas, I can't do this anymore. With the pots out, there is no way to power
my AR with a single amp and maintain any semblance of balance between the
energy sent to the woofer and that sent to the mids and tweeters. And I'm
NOT putting those pots back in the circuit. I itched for three days the
last time I opened those boxes.

Peter did you ever look at your audio signal on a scope to see the height of
the transients? I look fairly often and I've never seen peak voltages as
high as you describe.

Regards,
Jerry