Pa 100, updates and prob with reverb

[doc538]

Hello, I have a pa100, recently the reverb stopped working, you can hear it but when you turn it up the volume goes way down..Another problem is the total output of the amp is low, it was better much then just dropped by 40%, about the same time as the reverb..

I want to use this for a guitar and as long as it is open I guess its time to change the input resistors... The caps have been changed at some point they are a black plastic no name.. Although the filter caps are mallory.

tubes are all RCA no idea how old, except for one Mesa. This is the first tube amp I've opened in 25 years so please bear with me.

[doc538]

WEll I fixed the reverb problem, but still looking for mods to this unit a it is basically a twin reverb with 4 channels, would like to make one channel an overdrive

[doc538]

Wow, can't believe its been over 6 years. Hard to believe no one posted an opinion either. Well just in case someone out there has an PA100 and wonders what to do with it I can give a simple solution, Just play it! I pulled mine apart and installed new filter caps, spent some time checking resistors and cleaning things up. Replaced channel 1's input resistors to match a guitars impedance, later on I replaced the signal caps with orange drops..that really opened up the sound. Added a switch to cut out one pair of 6l6's to save my eardrums. Now I have a fantastic sounding amp for guitar and vocals with a real spring reverb.

Never did make a channel for overdrive, I just plugged in a pedal. I would do it with the right schematic, just because it would be fun.

I also discovered that someone had installed a 3 wire ac plug, unfortunately they left it attached to the a/b switch and left in the killer cap! Removing the cap and a/b switch also reduced hum.

[mikeydee77]

WEll I fixed the reverb problem, but still looking for mods to this unit a it is basically a twin reverb with 4 channels, would like to make one channel an overdrive

What was the trouble with the reverb?

[Jazz P Bass]

Cool post.
Let's see what happens in 6 more years.

[olddawg]

It my not break your ears (although it definitely could). But it certainly can break your back.

[doc538]

What was the trouble with the reverb?

Total amp volume went down, way down, when I turned up the reverb. With reverb @9 volume out was near 0. Turned out to be dirty rca jacks and tube socket. Cleaned them up and volume came back along with the reverb.

It my not break your ears (although it definitely could). But it certainly can break your back.

U got that right! this iron is HEAVY, weighs more than the Marshall 4x12 cab It sits on in my garage. As for my ears, I have already replaced both drums and hearing bones, but only one works a little so I need the VOLUME But I don't need stereo!