VHT Pitbull 50/12 reverb

[drewl]

Anyone familiar with these?
there were a few versions, this one seems to be from the late 90's.

Anyway, no reverb.
No signal on pins two or seven of the 12AX7, earlier units used an EL84 driver, but this is wired for an A?7.


it has a reverb trans that measures good.

There is nothing connected to pins 2or 7!
At least not that I an see.
Injecting a signal on pin 7 and the tube amplifies.

There is a low signal nearby on a cap that is also connected to pin nine which also has a 1meg to ground.
No filament voltage on pin 9.

Weird layout Don't suppose anyone has a schematic?

Thanks.

Return amp is fine

[drewl]

Ha, I don't think the reverb ever worked on this, it's like they were going to convert the EL84 driver to 12AX7 but didn't finish

Quickly wired it for EL84 and reverb works great, removed background hum also!

May have been when the company was being sold?

[Jazz P Bass]

Nice.
Real nice!

[drewl]

Well I had to wire up a 12AT7, the EL84 was pulling way too much current through it's 2k 5w B+ feed.
it was unsoldering itself!

It has a 680 ohm 2 watt cathode resistor, the EL84 pulled around 50v across it, the cathode cap is 100v.

With an AT7, cathode voltage is around 20v, but doesn't pull anywhere near as much current across the 2k voltage dropper.