Finally had a chance to get back to it.
T4 Pin 1 -37.3v
       2 +33.9v
       3 -37.8v
T5 Pin 1 +0.6v
       2 +36.2v
       3 +28.6v
T6 Pin 1 +33.9v
       2 +34.1v
       3 +33.7v
Amp is still on dim bulb tester

Quote from: Jesse on Today at 02:21:50 PMAny book recommendations for Electronics Repair / Troubleshooting?

Lots of good suggestions in this thread:  https://www.ssguitar.com/index.php?topic=439.0

It works! Thanks again g1!
The tricky part for me was missing the fact that the replacement part I purchased for Q9 had a metal backing, where as the original did not. See attached photo.
Any book recommendations for Electronics Repair / Troubleshooting?
Thank you again everyone! I look forward learning more here

If the rectifier's are not in circuit then there would be no B+ vdc. So I can't immediately imagine the caps are the issue from that standpoint. Of course posting a schematic would be a good thing. It seems the transformer may have other windings -/+15v rails and your heater's winding. Try disconnecting all secondary connections when in doubt. Light bulb shining with secondary taps disconnected from circuit is not good. Right now from what you have written we need to clarify what you are describing and a schematic. We need voltage readings if the light bulb is not shining bright.

Hi friends; It's been a very long time away. A lot of things got put on hold including amp repairs. I have been working on a Peavey Ecoustic 112 amp lately. Everything is running smooth and quiet except the reverb which is important for the new owner. I have reverb when I turn the pot up but I also get like a 60hz hum. I tried re-soldering, cleaning the pot, switched out the tank with 2 diff ones but nothing quiets it down? Does anyone have a suggestion? Looking through the Peavey Forum I found evidence that Peavey amps are known for noisy reverbs. Someone on there suggested using an isolation transformer which I have not tried.

Thanks for all the info and hints. I'm about to order the parts that I don't have in my stash and as soon as they arrive, I'll start breadboarding. Provided nothing unexpected gets in the way, that is.
As far as the higher voltage goes, I happen to have an LT1054-based voltage doubler put together, so I'll give it a try at roughly 18V too.
Have a good one and stay tuned!
M

I'd try 10pF to 22pF, base to collector, similar to the trick employed to smooth down silicon transistors in fuzzes, but that's a matter of taste
I had a bit of downtime this arvo and threw the Vulcan on LtSpice: the frequency response is VERY similar to the Randall RG100Es, so you'll probably hot rodded marshall vibes. That doesnt mean that it will sound like a Randall, though: clipping thresholds and gain increments are very different.
I was also surprised to see that the circuit, as is, is already shaving off some dBs above 6kHz.
I'd be tempted to try it at higher voltages, with low hFE transistors, just for the sake of it.
Oh, and the diodes do mimic grid clipping: they chop almost half of the waveform before the gain stage. Very clever design with just a few parts

Thanks for the reply, Umlaut.
Looking at the schematic, I also expect it to sound like a Marshall on steroids. Like a DSL or a Bogner Ecstasy perhaps?
Speaking of snubber caps, do you mean in parallel with collector resistors?

Hi there!
I have this one on my to-breadboard along the line.
Seems to be marshall-voiced, judging by the filtering, and pretty high gain.
Might be wrong, but perhaps the diodes mimic grid saturation as in a valve amp.

Indeed breadboard first, especially if using other trannies, and check the voltages. Personally I'd try snubber caps on the last two gain stages.

Good luck!

I have a problem with a multi watt dual rectifier head.
It keeps blowing fuses and a rectifier tube.
Using the light bulb mains lead method, even with both rectifier tubes out of the unit and on standby it seems to be drawing quite a bit of current. No change with power tubes also removed.
Is this likely to be the large filter caps going or any other suggestions?
Thanks in advance