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My bass amp keeps cutting out!!!


 
8/14/2000 7:04 PM
Greg
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My bass amp keeps cutting out!!!
I have had this problem for a while, and no one seems to know anything about it. I have now called Ampeg and Samson (makers of Hartke) and asked this same question to both: neither can offer any suggestions.  
 
The deal is: I own 2 heads - one Hartke and one Ampeg. Both keep cutting the signal to the speaker. I have replaced the speaker, the wiring, the bass, and the power cord...none of which stopped the problem. So: I have now replaced every part of my setup, and I still have the same problem. It happens in various locations, so it's not the power source, either.  
 
When it happens, I'll be playing at a normal volume and something will click inside the amp and all sound will cease. If I unplug my bass and touch the end of the cord, it doesn't hum. Then, a few minutes later, the amp clicks again and bing! I've got sound again. This happens on both amps.  
 
What could it be? Overheating? Clipping? Impedence mismatch? None of the technical personnel I have talked to seem to agree with any of these ideas. And still no one knows what I can do.  
 
HELP!!!! I am at a total loss.  
 
Thanks.
 
8/14/2000 7:25 PM
Doc
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I wonder if your speaker has a partial short in the voice coil, or if it rubs the frame when it gets warmed up. These (solid state?) amps probably have protective circuitry which is doing its job correctly, limiting output stage overcurrent.  
 
Try a different speaker cabinet for a while and see if the cutout no longer occurs.
 
 
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8/14/2000 10:10 PM
Bob P
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Could be a broken or loose solder joint. I see it all the time. Something heats up and expands and contact is broken, cools down and reconnects, then heats up, cools down, etc. Could be a bad guitar cable or input or output jack. Does it happen when plugged into a different speaker?  
 
Also some solid state components have built in thermal protection circuits. Check current draw on these components.  
 
Bob P
 
8/15/2000 3:14 AM
Bruce
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Is the click sound coming from the amp or is it coming out of the speakers?  
Bruce
 
8/15/2000 3:39 PM
Greg
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All of these suggestions are good, but I'm a step ahead. I have replaced all wiring (including the cable from the bass to the head). I have, in fact, replaced every single part of my rig - speaker, wiring, head, bass, and all. So I know it's not the cabinet, the wiring, etc. My only thought at this point is that I must own 2 heads with the exact same problem...?  
 
Anyway, the clicking seems to be coming from the head, not the speaker. If it is some sort of thermal protection thing, what can I do about it? My next step, in case you are about to suggest this, is to try keeping a fan pointed at the back of the amp and see if that helps.  
 
Could it be that 350 watts just isn't enough? It seems ludicrous, but...  
 
Keep me posted with your ideas, and thanks so much for considering this with me.  
 
Greg
 
8/15/2000 3:49 PM
timv
Are you always playing at the same place? Meaning this is just happening at practice or in your room or something like that. There is the possibility that your line voltage to your house is low and the amps cannot create the power they need without warming up excessively. I saw this happen at an outdoor fest one year and the pa power amps kept cutting in and out because the thermal protection kept shutting them down and this was because the line voltage was lower than normal. If this happens at various places that sort of rules that out. Just a thought. What type of cabinets are you using? Ohms ect?
 
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