Reverb Tank ID?

[Oddvar R]

I have an old PCL VA1956 amp, said to be a Mark 1 clone. It has a setup for reverb tank, but the tank is missing. Is there a way to decide what tank to use?

[Stevem]

Please list what it has for preamp tubes and post up some good pictures of the outside and inside of the amps chassis.

The inside pictures should consentrat on the wires going from chassis connections to the reverb tank and back to the tube(s) those wires connect to.

[Phil_S]

I don't know if this will help. This describes the numbering system for Accutronics tanks. I believe MOD uses the same system.
https://amprepairparts.com/reverb_numbering.htm It says that 8AB2A1B is the usual for a Boogie amp but that may or may not be correct.
https://www.amplifiedparts.com/products ... y-3-spring says MOD tank 9AB2A1B.
These two codes match except for the first number, which is the size. #8 is 9" and #9 is 17", so that is easy enough to determine.
Pay attention to the orientation of the tank. This is the last number. Get the one that matches the orientation in your cabinet.
One problem is that your amp is a clone. It is not a sure thing that the builder used the same basic tank (input and output impedance, and ground.) This is why you may want to post the pictures that Stevem asked for. You may get better information.

[Oddvar R]

The tube which might be for the reverb 12at7, the rest are 12ax7's and 2 6l6GC 430 Mesa tubes.

[Oddvar R]

Inside

[FUCHSAUDIO]

Since there appears to be a reverb driver transformer, I would venture to guess a Fender style tank should work out okay. Looks like an Engl build.

[Stevem]

That driver transformer says 4 ohms on it so the I input side of whatever pan it takes is not a standard 8 ohm Fender type it would seem!

[didit]

The clearest reverb transformer photo shows markings of 0 8 15k Ohm, then 4 followed with ambiguous lettering. Photos with other angles and tracing of circuits back to tubes and tank connections would help definitively.

Best .. Ian

[Oddvar R]

The transformer says: 0 8 15kOhms 4Ohms. (A2-2 Watt)

The "0" goea to the tube in the middle, which is a 12ax7, the the "8" goes to a resistor on the boar in the filtersectyion and then to the voltage selector. The other two goes to the the 5 pins din plug. One lead from there to the reverb pot.

[didit]

The transformer says: 0 8 15kOhms 4Ohms. (A2-2 Watt)

The "0" goea to the tube in the middle, which is a 12ax7, the the "8" goes to a resistor on the boar in the filtersectyion and then to the voltage selector. The other two goes to the the 5 pins din plug. One lead from there to the reverb pot.

What tap has connection out from transformer to the tank?

[Oddvar R]

The transformer says: 0 8 15kOhms 4Ohms. (A2-2 Watt)

The "0" goea to the tube in the middle, which is a 12ax7, the the "8" goes to a resistor on the boar in the filtersectyion and then to the voltage selector. The other two goes to the the 5 pins din plug. One lead from there to the reverb pot.

What tap has connection out from transformer to the tank?

It's difficult for me at least, to trace the routing. Therer are two jacks on the back: echo in/out, and the trafo goes to the DIN plug. as shown in the pics.

[didit]

A schematic would be most appropriate. Or simple sketch of just the reverb section. That said, fairly clear "4 Ohm" tap connects to the tank. The "15K Ohm" section seems your plate load. Fender's transformer spec with 12AT7 is 23-25K ohms into an 8 ohm tank. And that type, slightly mismatched at perhaps 6.5 ohms, would therefore be close enough for rock&roll. You will need to get the correct DIN plug and then carefully trace. it's easy to create hub issues with tank grounds & connection. Take your time and good luck.

Best .. Ian

[Oddvar R]

No chance of a schematics it seems. The PCL factory promises to send info, but never seem to around to it. But the info is appriciated-

[didit]

No chance of a scematics it seems. The PCL factory promises to send info, but never seem to around to it. But the info is appriciated-

Drawing this schematic is simply work of carefully tracing.

Best .. Ian

[Lothy]

Just stumbled over this topic. Hope this helps anyway.

vintageamp_VA1956.jpg

Cheers
Gerhard