Premier Rock Forum

Looks like a 4x10 version, but I think they are the same head unit...

that looks like a vt-40, which according to the ampeg book has the same preamp as the v-4, but instead of 4 7027a power tubes, it has 2.

Is the vt-22 a different preamp? I always assumed the vt-22, vt-40 and the v-4 were more or less the same.

the v-4, v-4b, and vt-22 are all the same, with the one difference being that the v-4b doesn't have reverb. according to the book, the vt-40 has the same preamp as the v-4/v-4b/vt-22. the v-4 is the head version of the vt-22 (2x12).

yeah, nobody uses 6L6 tubes in anything. they're 6L6-GC's. when you say 6L6, that's what they give you. amps that run 6L6 are running 6L6GC's. the original 6L6's are metal bottle, which is why they have the "G" models ("Glass Bottle") like the GC we all use and the WGB which is very similar but lower powered and comes in Fenders, the current-production Traynors, etc. The 6L6WGB is also known as the 5881.

The 7027 and 6L6GC are the same tube, except a couple *extra* pin connections on the 7027. As long as your amp has the screen wired on pin 4, the plate on 3, and the control grid on 5, the cathode on 8, and the heater on 2 and 7, with nothing on 1 and 6, you can use 7027 or 6L6 interchangably.

You could also pull two of the power tubes and get wikked sounds at lower power.

I thoguht QOTSA from playing a cranked V4 as well. Really nice thick, meaty overdrive.

VT-22 is the same as the V4 as far as the circuit is concerned.

7207A is the same as a 6L6GC as Scott states above...

the 12dw7 in a lot of these amp is under far to much stress and the burn up quickly. I would have to see this particular amps schematic to let you know if that is the case.

Either way grab some replacement tubes.

The speakers are either CTS or Eminence.

Does this amp have master volume or distortion knobs?

madlee wrote:
do you mean that the 7027A is like the 6L6-GC?

Yes. I am under the assumption that people will be using the 6L6GC instead of the 6L6 because of the fact that many of the later amp designs were designed around the 6L6GC. --I apologise for confusing people about this, as older 6L6 designs will not handle the voltages in an Ampeg, and will further not output the same wattage of a 6L6GC.

TheMilford wrote:Does this amp have master volume or distortion knobs?

No distortion knobs. But it is a master volume model, with the master control at far right and the pre volume controls for each input at far left.

I have a VT-22 which was taken out of the combo box and put into a head box, since the VT-22 in a combo box is so god damn heavy. The same thing happened to me, didn't seem to be as loud as I was hearing they were supposed to. I just replaced all the tubes and had the bias set and now it's loud as hell. Got mine for around the same price as you too. Any repairs are completely worth it. Great fucking amp.

FYI: There is a whole Ampeg V-4 fansite (http://www.ampegv4.com/), just for future reference, it's got some pretty cool information and links.

I looked at that site, as well as www.fliptops.net. Lots of great info. I took the amp to my tech and told him to give it a full once-over, replace power and preamp tubes if necessary and bias the amp accordingly, as well as check the caps. He usually does great work for me and many people I know, so.....looking forward to getting it back and playing through it.