I'm new to the forum so I apologize in advance if I am not on the right board for this.
I recently built a Dumble Steel String Singer #002 and, after playing for many hours yesterday, the reverb started to cut out for about one minute here and there before coming back. Everything else seems to be working fine when this happens. Therefore, this is likely somewhat isolated. The tank was fairly new, and I don't think it was handled too roughly before the final build.
Troubleshooting tools at my disposal:
Quality True RMS Multimeter
Oscilloscope
As this continues, I will post updates. I plan to create a reverb crash when it cuts out next time for starters. I have checked the RCA style tank wires they seem to be connected fine. Any other tips would be great. I am trying to avoid removing the chassis if I can.
Last edited by wesmiller94@live.com on Mon Nov 16, 2020 5:21 pm, edited 1 time in total.
It's a Dumble amplifier, or a clone of one at least. I think general tips for troubleshooting the reverb section of an amp for a symptom like that is all I'd need. They are kind of fender-ish.
intermittent faults can be a pain sometimes. It can be a component like a resistor or capacitor, in the signal chain, that is faulty but only goes south as it heats up from use. It could be a solder connection that as it heats up, also starts cutting out.
The most common tool for tracing this kind of problem is to get a wooden chopstick, wait for it to start failing and probe around that part of the circuit seeing if a specific area causes the noise to go away or get worse etc.
I think Stevem's comment might be more that the amp is a dumble and a lot of the dumble specific knowledge tends to live in the 'Dumble Discussion' thread, I'm pretty sure he knows what one is...
I am reposting this here after I posted this on the wrong forum. I was wondering if anyone could help me out.
I recently built a Dumble Steel String Singer #002 and, after playing for many hours yesterday, the reverb started to cut out for about one minute here and there before coming back. Everything else seems to be working fine when this happens. Therefore, this is likely somewhat isolated. The tank was fairly new, and I don't think it was handled too roughly before the final build.
Troubleshooting tools at my disposal:
Quality True RMS Multimeter
Oscilloscope
As this continues, I will post updates. I plan to create a reverb crash when it cuts out next time for starters. I have checked the RCA style tank wires they seem to be connected fine. Any other tips would be great. I am trying to avoid removing the chassis if I can.
Well I think I got it. It was a poorly soldered footswitch jack. The ground was making a connection with the switch wire.
I poked the wire with a straw and it started to crackle. Once I poked it a little bit harder, the reverb cut out and came back when the pressure was released. Since I rewired/soldered it, it hasn't cut out since. I checked everything else while I was in there and it all seems pretty solid. If it happens again I'll be surprised.
Thanks for all the tips guys. I was primarily concerned it would be something way harder to find (like my last issue).
