Vox Pathfinder 15r low volume

[mweishaar]

Hi everyone,
Just bought a Vox Pathfinder 15r that I knew wasn't working correctly. Previous owner said the amp works fine w/ the headphone jack but no output from the speaker. I cleaned it up yesterday and then played around with it a bit and there is very low output from the speaker if I turn the gain and volume up.

Any pointers or tips on what I should be testing to determine the problem? I was initially thinking bad switched headphone jack until determining that I could actually hear the very low output from the speaker.

Thanks in advance for any help or tips!

Thank you,
Mark

[Jon Snell]

I would firstly check the headpone and speaker sockets then the speaker.
If that doesn't point to the fault, follow the signal path with your oscilloscope to find out where the level drops off. Path15R_Schematic.pdf
I always go from output to input, it makes sense logically.

[mweishaar]

Unfortunately, I don't have access to an oscilloscope - might be over my head in thinking this would be an easy fix

I just tested headphones and while I can hear them better than the speaker itself, it's still not as loud as I'd expect and it seemed like I still needed the gain turned up to hear any output.

[Jon Snell]

Something simple to do is slap the case; does the reverb sound loud and proud?
If it does there is a pre amp issue = not an easy fix. If not = power amp fault possibly C23 open circuit/low capacitance.