Hiya - so far it seems to be. Not yet had time to fully test it for several hours. Once I have done this I will certainly post and update
Ok - after almost 2 hours of my house-mate playing a guitar through it on a distortion pedal it has not cut out. Looks like the extra heatsink is working well!
Great. Thanks for these tips. I think I have the same problem. What type / size heatsink did you use?
The result of the problem is solved but is the problem in itself solved?
I rarely see an AER pass by and they are not very kind when asking for a schematic.
On the other hand, all problems were easy solved (jacks, pots atc).
I never had one with a serious problem.
So back to the beginning.
Why is it overheating?
Oscillations are the most probably cause.
Check if the grounding of the everything that's connected to ground is wel fixed and with a good contact to that ground.
Oxidation can be a problem.
Hint: It would be great if someone at AER would smuggle out a collection of schematics and post them...
I rarely see an AER pass by and they are not very kind when asking for a schematic.
On the other hand, all problems were easy solved (jacks, pots atc).
I never had one with a serious problem.
So back to the beginning.
Why is it overheating?
Oscillations are the most probably cause.
Check if the grounding of the everything that's connected to ground is wel fixed and with a good contact to that ground.
Oxidation can be a problem.
Hint: It would be great if someone at AER would smuggle out a collection of schematics and post them...
Its almost certainly RF. Check the earth on the guitar lead. Make sure the chip is screwed down tightly and insulated. From memory pin 8 is minus hot so the tab must float!
The discharge resistor has nothing to do with cut-out fault. Look for RF before you do anything else because that power IC is prone to that.
The discharge resistor has nothing to do with cut-out fault. Look for RF before you do anything else because that power IC is prone to that.
Hello,
After a few years ...
I am repairing an AER Compact and as I reded before, they are rarely "out of order".
The one I have under hands has no sound. Preamp is OK but the final power circuit is failing. Without schematics it's quite hard to understand, is has the TDA7294 amp and a 2180LC voltage controlled amp.
I will send a signal through the preamp to follow the signal and try to find out where it fails.
But anyone has any tip or any suggestion ?
Power supply is ok, filter caps are ok. What else should I check ?
Thanks.
After a few years ...
I am repairing an AER Compact and as I reded before, they are rarely "out of order".
The one I have under hands has no sound. Preamp is OK but the final power circuit is failing. Without schematics it's quite hard to understand, is has the TDA7294 amp and a 2180LC voltage controlled amp.
I will send a signal through the preamp to follow the signal and try to find out where it fails.
But anyone has any tip or any suggestion ?
Power supply is ok, filter caps are ok. What else should I check ?
Thanks.
Yeah, I checked, of course.
The signal get "lost" jus at the resistor of the input of the 2180LC amp. The following part is working ok.
So, I will order and substitute the 2180 IC.
What I don't really understand is why it failed... I'll check with the scope.
The signal get "lost" jus at the resistor of the input of the 2180LC amp. The following part is working ok.
So, I will order and substitute the 2180 IC.
What I don't really understand is why it failed... I'll check with the scope.
Hi again.
I find the problem !
Simply the THAT2180LC is failing.
Great ! Easy.
BUT the problem now is to find a replacement for it.
I'v asked my locals providers: they don't find it
I´v contacted AER: no answer
Alibaba: No stock
Mouser: No answer. Not in stock
Farnell: No stock.
Aliexpress: No stock
...
Where else could I search ???
I find the problem !
Simply the THAT2180LC is failing.
Great ! Easy.
BUT the problem now is to find a replacement for it.
I'v asked my locals providers: they don't find it
I´v contacted AER: no answer
Alibaba: No stock
Mouser: No answer. Not in stock
Farnell: No stock.
Aliexpress: No stock
...
Where else could I search ???
Many thanks.
I found it at EAR, they answered after a few days (today), they have spare parts.
So I'll order it wright now.
I found it at EAR, they answered after a few days (today), they have spare parts.
So I'll order it wright now.
Hello,
Well it sounds now but still have a few issues.
It sounds low and distorted...
Does anyone knows where to get the schematics ? It's much easier with them ..
Thanks
Well it sounds now but still have a few issues.
It sounds low and distorted...
Does anyone knows where to get the schematics ? It's much easier with them ..
Thanks
IF it´s a bleeder resistor then it´s irrelevant whether the unit oscillates or not, its purpose is to discharge main filter caps after amp turnoff.
That it´s "near" the main caps means nothing, check what is it connected to.
It may very well be a dropping resistor to get a lower voltage to some other amp section.
IF it´s a bleeder resistor 100k is way too high, it´s more of a "tube amp" value than an SS amp one.
IF you want a bleeder resistor to discharge those caps reasonably quick solder a 1k 2W or 3W resistor across each cap.
Yes, I "did the Math".
Each will dissipate around 1W (I expect about 30V rails based on cap rating), and will discharge those caps to about 1V in about 15 seconds.
100k resistors will take 100 times as much, of course.
But again, re re re check where from to where to is that resistor connected.