My amp is warbling!

[ViolenceOnTheRadio]

Not sure if anyone has encountered this but for some reason, my amp is producing this really annoying warble that sounds like chorus and I absolutely HATE the chorus effect! I thought it was from the mods I made to my pedal the last few days but after bypassing then plugging in direct I found it was the head causing this ear tone blemish I am now dedicated to eliminating.

It didn't do this a week ago and just started. It's a solid state head, has anyone ever heard of this happening?

[BubbaFet]

    Which make SS amp head is it?

    Got a schematic?

    Maybe ask over at http://www.ssguitar.com/ or at http://www.diyaudio.com/ ?

    I'd guess a power-supply-filtering-electrolytic capacitor is going bad and adding some 120 Hz modulation to your notes.

/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ etc.....
.

[petemoore]

  This isn't an amp forum, but for a minute I'll pretend we're working safely with small voltages, I can do that, you can't.
  SS means no tubes, only thing left is resistors and wires, they don't tend to 'warble'.
  That is, besides:
  Caps can to 'time constant stuff' like warble.
  In the power supply caps tend to get hit.
  Power supply and transistors seem to be working, [overgeneralizing, but] generally these items work right or don't work.
  If you want the power supply right, it's either ok now or needs attention, same thing for the rest of the amp, where to start having luck statistically, ime, would be with the capacitors, the big ones.
  Make sure it's worked on by someone who is familiar with draining the B+ voltage.
  Does it warble all the time [under different conditions?

[ViolenceOnTheRadio]

I realize this isn't the right place to ask but figured it wouldn't hurt.
I had suspected what bubbafet is also guessing but had reeeeeally hoped someone would offer that it could be from an op amp having a short of some kind which would obviously be the easy, cheap fix. lol

I just had this sucker apart, have wired in about 7 or 8 of my own circuits over the years and while my work is very neat, it's still quite the task to dismantle since it's just one large PCB that includes both the preamp and power stage.
I suppose I should view this as a blessing in disguise...if this is indeed the problem. I had thought of making the upgrade to better power caps before anyway.

[petemoore]

  I don't know anything or enough about it to say I know anything about it.
  Inkling that it may be working fine, at least/even the capacitors.

[ViolenceOnTheRadio]

Turning it on this morning and notice it's no longer doing it which means once it's good and warm, I can assume it will start again. Another clue pointing towards the power caps. I had noticed this warble in the past but it was always so very vague and occurred rarely. Now it's increased and is severe after the amp has been on long enough to get good and warm.

So again, the evidence is leaning towards the power caps imo but I am also inexperienced with high voltage power circuits Petemoore. I suppose it can't hurt to upgrade the power caps anyway and I know I can safely discharge them so no worries there. The work is simply dreaded and to add to that, Xicon has discontinued my favorite caps!!
The neon green ultra high and ultra low operating temp caps. Always noticed they had the cleanest, smoothest sound in my pedal circuits. Always wanted to swap out the stock power caps for these in the past and it looks like sitting on the idea has buried it. I will only be able to replace 1 value with these of the 4 I'll be replacing.

I'll also ask at that DIYaudio forum you linked Pete and see what they have to say...and also email Xicon with a wordy message urging them to rethink their blunder!

[Nishmaster]

No need to get crazy on power supply filtering caps. They're not really in the audio path.

Get high quality electrolytics rated for the proper voltage (no tubes so it probably won't be super high voltage) and temperature, drop them in, and keep playing some music.