Question about JTM45 clone quirk

[jw71]

Hi,
I have a JTM45 clone. It sounds great, but it has developed a quirk within the past couple of weeks. After playing it and then putting the standby switch on standby, it makes a crackling sizzling noise through the speakers for a few moments. The noise fades away after about 3 seconds, but is definitely noticable (reasonably loud) until it stops.

Any ideas?

[John Ward]

It is just the sound of the amp as the high voltage runs down. It's a good thing.

[BrownIsound]

Carbon comp plate resistors?

[jw71]

Carbon comp plate resistors?

I am not sure. Does this help?

http://i71.photobucket.com/albums/i132/jw71/100_0622.jpg

:o

[JimmyR]

Yup those are almost all carbon comp resistors. They have the mojo apparently, but also the noise!

[VaughnC]

Yup, carbon comp resistors can absorb moisture and do things like that. However, you could change all the 100k preamp plate resistors to film type of the same value and that would probably make the amp quieter, but might also change the tone to some degree.

[5881]

My Rockytop 45 does the exact same thing, and I never got around to asking why, though I was sure something was amiss. Good to know it's the nature of the beast.