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need4mospd need4mospd is offline
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Default Blown power amp channel?

On Mar 8, 11:27 pm, "Paul Stamler" wrote:
"Scott Dorsey" wrote in message

...



need4mospd wrote:
I was wondering what kind of damage was caused to my amp and if it's
worth trying to fix it. I accidentally used a 1+/1- speakon
cable(wrong one) on my Crest CC1800 with the switch in bridged mode.
Now the amp will cut off channel A when the input gets too high. By
cut off, I mean the ACL(Automatic Clip Limiter) lights up and the
sound is completely stopped, then it returns to normal after a few
seconds. Channel B works fine for now. Bridged mode acts similar to
channel A. Also channel A works normally under a very small load for
at least an hour or more, but I need to get more volume or else this
is useless to me.


Is this amp pretty much toast on channel A? Or is this a simple easy
fix at my nearest service center?


It's going into protection for some reason. My first guess would be a
blown output transistor, but a tech with an ohmmeter will be able to tell
for sure.


And for future reference, you should look at the specs for that amplifier
and see if it's rated into a 2-ohm load, because when you hang a 4-ohm
speaker onto a bridged output, each channel sees 2 ohms. If it's not rated
into a 2-ohm load, just use one channel.

Peace,
Paul


It's capable of 4 ohm bridged or 2 ohm per channel according to Crest.
One of the reasons I got it.

I played on it again tonight and used Channel A with the ACL light
coming on after about 5 minutes. After switching the amp off and on
again it kept going steady at a decent volume for around 2 hours til I
shut it down. So after warming up it works fine in parallel mode. When
I bridged it later on it clipped under higher loads.

Any more thoughts before I take it in for repair?