semi OT: AH I think i just blew my practice amp :(

[Hal]

So i was playing around with my multiface, and i just poped in a higher value input cap...and my amp started humming a lot.  I turned it off, looked around the board to make sure ground was connected, but the old cap back, and turned the amp off.  It was fine, until about a minute later, it started humming again.  I think unplugged the multiface, and plugged my guitar straight into the amp.  Again, hum after a minute or so.  Slowly gets louder.

Any idea what that is ? The amp is a Crate GX-15R, from about 6 years ago (i think the warrenty's up)

THanks :-D

[petemoore]

Unplug the cable to the amp...test for results.
 Plug a different cable [known good] into the amp, don't let the tip of the other [unconnected] end touch anything...test for results.
 If it's in the amp, after performing these tests you'll know, because the hum will be there, 'regardless'.
 Try a differnt cable.

[Peter Snowberg]

If it is failing, it's probably a power supply capacitor and should be easy to fix. It could also be a diode that heats up and stops working in any case if you have a second anp you could always trace the power supply with an audio probe. Turn the test subject all the way down after it starts humming and audio probe the power rail. If you have hum anywhere after the filter caps something is blown in the supply. It probably had nothing to do with anything you were doing.

Good luck,
-Peter

[Bluesgeetar]

Dido on the cable thing!  Friends at Guitar Center are always giving me junk used cables.  I have had the exact thing happen a few times with crappy cables.  
Now all I have is spectraflex or monsters.  I am though gonna get me a few of those curly jobs at Ratshack to see if there really is some mojo there.

[Hal]

nope, not the cable...was just playing with the same cable with my other amp.  Damn.

Peter - thanks so much!  I'll try that when I get the chance :-D

[lightningfingers]

I am though gonna get me a few of those curly jobs at Ratshack to see if there really is some mojo there.

All I use now are curly cables (even the little ones that link the pedals).
Curly cable mojo is cool :mrgreen:

works better if they are really long curly cables. Mine are 4.5m (when coiled up )