Hum and pops on power up

[nee]

Greetings all,

My Trainwreck homage always pops and farts, with a loud hum, for two or three seconds after I flick the standby on (i.e. so the amp is operating).

The bad noises always go away so it's not a real biggie, but I wonder what could be causing it?

Thanks!

[PlinytheWelder]

Which circuit it it?

[guitarsnguns04]

check your filter cap wiring to the standby switch. Make sure its on the right side .

[nee]

Which circuit it it?

Pretty much taken from the 12/4/08 schematic. (Not being in the USA I'm not sure if that's April 12 or December 4!)

[rooster]

Hey. Typically as someone mentioned the power cap string can be a cause of this kind of noise. So maybe you are running cheap power supply caps? Could be your solder joints here, too, but more than likely the caps themselves.

Ok, next would be the coupling caps, the .002 and the .1 specifically. A bad cap or solder joint here can cause this, as well. Swap one or both of these if you question their quality, and yes, that's where I would start. Good luck.