Need schematic - Gretsch Playboy (built by Victoria)

[caverat]

Need a schematic / service info for a Gretsch Playboy amplifier. Model G 5156. This is the one built by Victoria Amplifiers in Indiana, uses 3 12aX7 and 2 EL-84. Not the same as vintage Gretsch amplifiers.

It has a weird tremelo issue; the pulsations appear throughout the circuit on the B+ lines, power supply filters are OK. Tubes OK. Also breaks in to a loud hum if the intensity control is set to minimum or maximum; OK midway positions.

[Jazz P Bass]

I found a Valco schematic that is supposed to be the 'newer' Gretsch G 5156.
It uses the 6973 output tube.
Maybe this will help. (adjusting for the incorrect output tube pinout.)

[caverat]

Thanks, but this is quite different. That appears to be the vintage amp. The one I have is newer, has solid state rectifiers and three EQ controls (Bass, middle treble)

[Jazz P Bass]

Well, I did not really expect the schematic to be a match.

I was more concerned with the Tremelo, as that is the problem that you are having.
Is the Trem circuit close to what you have?

[caverat]

It is similar in basic design but they tie it in differently. I am trying to work with it though and figure out the differences. I did find this amp had a bad mid range control so I also have to fix that. (Open segment). Didn't fix the tremelo problem though, although I am beginning to wonder if something took out the control as well as did something else to the circuit. Unusual for a control to just go completely open like that....

[teemuk]

The Victoria "reissues" actually are not that at all. They have more resemblance to vintage Fender amps circuits than anything ever made by Gretsch, Valco, Supro, etc. Persistant Google search should find schematics although Victoria no longer shares them.

[Jazz P Bass]

I would hope that they are varying the bias of the output tubes.

To me, that 'vary the preamp signal' always sounded like a*s.

[caverat]

Thanks to all. To bring you up to date in case anyone else encounters something like this, I managed to get this thing going, I put a scope on the tube in the tremelo circuit an found a high frequency present (200 khz) which was being coupled into the preamp tube. There it was upsetting the bias causing the tube to go into cutoff. There was no obvious cause, caps and tube good, resistors in spec. I ws able to eliminate it by adding a 56 pf cap on the plate to ground. It did not in any way affect the low frequency of the tremelo, but since 200 khz is in the RF region it took that out. (Bad design that didn't allow for stray capacitance is all I can figure)

That also may have been the reason for the control failure as I noticed this high frequency also present on the next stage going into the controls. Replaced the control and it is working good now.

Also found one EL84 red plating after a while, coupling cap was good, yet bias was dropping on that one tube. Changed tubes now it is OK. (Bad tube).

[bannane32]

Hi all, I know that it is an old thread, but I'm looking for the references of both PT and OT transformers for this model Victoria 6156 from 2005, any chance to get a owner giving me the references? that would be awesome.

[glebert]

I just had one of these on the bench that was having an oscillation problem. I replaced the standard JJ ECC83 that was in V2 with a lower gain JJ ECC83MG (medium gain) and the oscillation problems went away. Tremolo had less thumping too. YMMV.