Ddt light stays illuminated all the time when running even at very low volume but the amp does not get warm and sound does not seem to be affected.
4080hz. Amp ddt light come on one side with no speaker plug in to the channel..
DDT circuitry malfunction.
SOURCE: The DDT light on one channel stays on.
Disconnect the speaker wiring and speaker on the bad channel. Turn the level control(s) all the way counterclockwise and turn the amp on. If your DDT (limiting) light remains lit, it's time for a visit to your nearest certified Peavey service center....G.
SOURCE: what is DDT my system cuts out when DDT lights up
Go to http://peavey.com/support/searchmanuals/archived.cfm Their main site also has info. DDT is an active compression feature to protect the product .
SOURCE: Peavey 115 Low hum Low volume from input
The preamp section has a problem. It could be anything in the preamp but is OFTEN the input jack itself. They take a lot of abuse.
Also the insert jack contacts that forward the preamp to the power amp if no external FX are used can go bad.
Additional things are circuit board cracks caused by rough handling and also controls that have had the knobs mashed in which can destroy the potentiometers they are connected to.
SOURCE: I have a Peavey PV2600 amp that had some blown
Chances are you have NOT got all the bad parts out yet.
HINT: While cold starting an amp after it smoked, put a 150 wat lamp in series with the power cord to act as a current limiter... saves fuses and parts.
The DDT circuits PROBABLY look for amplifier DC balance AND no overload of power supply as protection.
They COMPRESS the audio when it goes above a certain level.
SO, to troubleshoot this you will probably need an oscilloscope.
LOOK for a supersonic oscillation that you cannot hear but MAY be driving the amps beyond the DDT trip point. Drive a pure low level sine wave into the amp and follow it through to see at what point the DDT compressor senses an out of range level.
Remember it HAS worked before, and there is still a bad part in the unit. DO use my suggestion to limit the current as often while troubleshooting this type problem, the signal will suddenly go to a point to fry something, then you get to replace all the parts AGAIN.
SOURCE: hi,my peavey amplifier cs 4080
Ouch! That is an expensive one... a little over $7 here:
http://search.digikey.com/scripts/DkSearch/dksus.dll?lang=en&site=US&WT.z_homepage_link=hp_go_button&KeyWords=g30n60c3d
The BAD news is that USUALLY other things go at same time or cause the failure. If you miss replacing a second part that is degraded, then you blow out the new one. Pay particular attention to the gate limiting Zener diode... it may be blown open and would result in instant failure again. Also ALL parts associated with the gate drive of that transistor.
The circuitry for this amp is rather complicated and a lot of other parts need to be checked for damage before putting full power on the unit again.
When firing this up, put a 250 Watt lamp in series with the power input to act as a resetable fuse to avoid blowing out the part again... It is good to use a variac to slowly bring up the voltage at first. If the lamp stays lit, better keep looking for bad parts.
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I got a 4080 hz one side of the channel the DDT light come on with out speaker plug in to the channel.. And the fan not working on the same side channel..
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