Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Solid State Amplifiers => Amplifier Discussion => Topic started by: fopoman on October 12, 2009, 08:57:35 PM

Title: broken princeton 112 plus
Post by: fopoman on October 12, 2009, 08:57:35 PM
been reading on the net about this one.  Need some help.  The amp has a static sound continuously when turned on.  The static sound increases when the reverb level is turned up.  It pops when its turned on and off. Any help is great! thanks folks.

Nathan
Title: Re: broken princeton 112 plus
Post by: Enzo on October 13, 2009, 11:47:26 PM
Sounds like a chip in the reverb recovery stage went noisy on you.
Title: Re: broken princeton 112 plus
Post by: joecool85 on October 14, 2009, 02:03:39 PM
Quote from: Enzo on October 13, 2009, 11:47:26 PM
Sounds like a chip in the reverb recovery stage went noisy on you.

Couldn't something as simple as a dirty potentiometer or input jack do the same thing though?
Title: Re: broken princeton 112 plus
Post by: phatt on October 15, 2009, 02:30:34 AM
These problems are always a pain to track down.
Anything from a *Cold Solder* joint,,, but my guess is (A) a gain pot has gone OC
or (B) a PSU Cap on the way out.
Hope you get it all sorted out,, Phil.
Title: Re: broken princeton 112 plus
Post by: Enzo on October 17, 2009, 01:37:44 AM
To me the key clue is that the static noise is continuos.  A dirty pot would make noise while turning, but usually would not generate a steady noise.  And the amp's input jack from the reverb pan could be noisy, sure.  Usually that would be hum.
Title: Re: broken princeton 112 plus
Post by: joecool85 on October 21, 2009, 11:12:04 AM
Quote from: Enzo on October 17, 2009, 01:37:44 AM
To me the key clue is that the static noise is continuos.  A dirty pot would make noise while turning, but usually would not generate a steady noise.  And the amp's input jack from the reverb pan could be noisy, sure.  Usually that would be hum.

Good points, in that case I'm going to go with my second idea and agree with phatt, probably a bad PSU cap.  Although it could be a bad electrolytic somewhere else as well.  Probably a good idea to re-cap the amp.