Hi all,
I'm looking on some advice on how to proceed with a ss guitar amp repair. There is barely any volume at all maxed out. It's 100 watts, but putting out close to nothing. It's a 70's-80's amp made in the Netherlands. The company still exists but didn't get a direct reply to get a schematic... so that's the first issue to begin with. I've added some pictures in an attempt to show the traces and layout, hope this helps.
- PSU is good, rails are +/-38V DC
- Signal is coming in, gain 1 and 2 give distortion and clipping
- EQ section seems working correct as well
- Volume seems to be working
- 100 (large beige) ohms power resistor is good
- Changed the large IC with a known working one, same result
- Checked for bad connections... nothing to be found
- Speakers measure out 4 ohms (2x8 in parallel)
I'd like to hear your suggestion on what could be the possible cause of low output. The drivers are near impossible to measure from the top.
The outside drivers run quite hot compared to the inside that run cold. Could be something in the pre amp section as well...
I'm looking on some advice on how to proceed with a ss guitar amp repair. There is barely any volume at all maxed out. It's 100 watts, but putting out close to nothing. It's a 70's-80's amp made in the Netherlands. The company still exists but didn't get a direct reply to get a schematic... so that's the first issue to begin with. I've added some pictures in an attempt to show the traces and layout, hope this helps.
- PSU is good, rails are +/-38V DC
- Signal is coming in, gain 1 and 2 give distortion and clipping
- EQ section seems working correct as well
- Volume seems to be working
- 100 (large beige) ohms power resistor is good
- Changed the large IC with a known working one, same result
- Checked for bad connections... nothing to be found
- Speakers measure out 4 ohms (2x8 in parallel)
I'd like to hear your suggestion on what could be the possible cause of low output. The drivers are near impossible to measure from the top.
The outside drivers run quite hot compared to the inside that run cold. Could be something in the pre amp section as well...