Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Ryteone on August 04, 2015, 07:47:42 pm

Title: Fender Super Reverb - High Frequency When Placed In Standby
Post by: Ryteone on August 04, 2015, 07:47:42 pm

This one is strange, it's really a nice amp someone had converted it to a point to point wiring and done an amazing job with it.  But when you put the amp on standby it will let out a high pitch squeal that with rise in pitch and fade out after say 1 1/2 to 2 seconds.  It doesn't do it when you just kill the power, only when you put it on standby.


I've gone through and tried to make sure all the grounding was up to snuff, all the wiring dressing is in proper placement with nothing helping clear up the standby problem.  It happens with either channel turned up past about 1.  It also will do it with out without any thing plugged into the input jacks.


Does this sound familiar to anyone?  Any idea's?


Thanks so much in advance.

Title: Re: Fender Super Reverb - High Frequency When Placed In Standby
Post by: shooter on August 04, 2015, 08:45:38 pm

Quote

it's really a nice amp

guessing the amp works fine, with the standby exception?
you could try gator clipping a .01 - .1uf 600vdc from  B+ to ground (sorta a hi freq shunt?)
search the forum for "standby switch"  and see if you find anything.  You know if there are breeder R's on the pwr caps?

Title: Re: Fender Super Reverb - High Frequency When Placed In Standby
Post by: Ryteone on August 05, 2015, 06:07:55 pm

I will check that tonight when I get home from work.


Thanks...