SVT Pro 4 slow input current rise

[booj]

Well, not instantaneous. this amp has had the 100 + parts shotgun treatment, meaning all outputs and surrounding resistors, bias transistors, dioes and caps, power amp input transistors, diodes and caps. And here's what it does.
I'm monitering the AC input current on a 5 amp scale, and bringing up the input voltage with a variac.
At first all looks normal, with little current draw. I get mayabe 20 volts in and the current begins to rise. It continues to rise as I adjust the input voltage up to about 4 amps. At this point, I bring it up a little more and I hear a relay click, and the current drops down to a low level. I continue to bring up the voltaqge and again the current starts to rise to about 4 amps. I hear another relay click and again the current drops to a low level. I then bring up the input voltage to full voltage. The cureent level stays low for a few seconds. Then the current begins to rise, and within 2 - 3 seconds it's back up to 5 amps. While this is happening, I'm turning the voltage back down.
It's late. I've been at this all day. I'm tired. Call me a bad troubleshooter. I don't care. But if you could throw me a clue I'd appreciate it.

[Jazz P Bass]

Something is still shorted.
No way that amp should pull 4-5 amps at idle.
50-60 watts at best is my guess.

[booj]

Thanks for your response, Jazz. Yes, it appears there is a creeping short, but I'm thinking it may be the circuits ability to control the zero point. The feedback circuit going into the NE5532. I changed that chip out along with the TL084's, just to get that out of the way. I will confess that I ran out of 1N3070 diodes, (I needed a dozen) so I substituted a couple of FDH400's in their place, which have a slightly different forward voltage at a different current, but are still ultra fast recovery. I'll order some more of those to eliminate that as a culprit.
Could it be a problem with the driver circuit or limiter circuit, as in a bad E-cap or J176 fet?
svt4 pro amp.pdf

By the way, this is a different amp that the previous post. Thanks again for your input on that one.

[52 Bill]

You ran through a list of things that were changed, but never said what the original problem with the amp was. Care to share?

[booj]

Sure, 52 Bill,

One output on the Ch. B negative rail was shorted. Three outputs on the Ch. A positive rail were shorted. All 20 of the 1.5k 1/2 watts were open. The .47 ohm 5 watts connected to the shorted outputs were open.
The customer said channel A went out. Then he started using channel B only, but it "didn't sound right".
I left out the specific reference designators for simplicity.
Because of the way it is behaving now, I'm suspecting I'm getting closer to the core issue, or what it was originally doing before it blew. Ahh well. there's only a few more active components and diodes to change on this thing.
I suppose I'll troubleshoot the thing with the power amp section outside the chassis. Haven't gone that route yet.

[booj]

Got it. Output relay was fused shorted. Why that made it do what it did I don't know, but it's working normally now.

[Jazz P Bass]

Thanks for the update
I will put that one in the 'WTF' file for future reference.
The relay shunts the spkr + to ground when it is not engaged.
If the internals of the relay where really fused, that would put the output at ground?