Bridging reverb jacks for more gain?

[methodofcontrol]

i remember trying this w/ a standard RCA cable on my dad's fender twin some year's back, it didn't sound very good. more gain, but WAY more noise.
anyway...a friend of mine has given me his ampeg V4 for repair and there is no reverb tank, but the wires are present. i'm wondering if there's a better more "marshally" way to get gain out of bridging his reverb send and return?
in other words, i'd like to use the reverb tube as another gain stage effectively.
he's the kind of guy who likes a good amount of dirt in his tone, but cranking the V4 is not always an option. thoughts?

[nashvillebill]

I take it this is an early V4, without master volume or distortion?

First, I would definately NOT try bridging the reverb send/return. That's not what that circuit was designed to do, IMHO. More noise or perceived more gain, does not equal better sound.

I have one of these amps myself. They do what they are designed for very well, which is to put out lots of smooth power. The distortion that can be had, sounds very nice, but as you have found out, it's at ear-splitting volumes. Ampeg's founder did not like distortion (according to the Ampeg book) so their amps are not high-gain monsters. This scenario is typical of many guitarists, including myself: when we start out, we see people playing huge Marshall stacks (or hear about the Rolling Stones using Ampegs on their Get Your Ya-Yas live album). We buy these monsters, not realizing that these huge amps are useful only for very large concert events, and you can't get usable distortion at lower (home-practice room) volume settings.

so what's your choices? First, I'd put the correct reverb tank in there. This amp has a great reverb sound. Then for high-gain/metal, use a pedal. Also, it is possible to add a "master volume" control by plugging a 100K pot into the external amp out jack on the back, so you can crank the gain on the front but keep the volume down. Still, though, it's not going to be a Peavey 5150 high-gain head.

[methodofcontrol]

bill, you take after my own heart.
when i use my V4, it's loud and sounds great. if it's TOO loud, then i grab a smaller amp for the space i'm playing.
my friend, however, likes more gain than this amp has. he's been using an EQ pedal to slam the pre amp tubes, and in his defense
i think the sound he gets from that is far superior to any 5150 i've ever heard. also, he's not much for reverb. he wants the amp to work, not to necessarily be restored. and for the record, this is a late 70's distortion model. (we all know the distortion knob is useless. )

[nashvillebill]

Ok, looking at the schematic for the later distortion version: This shows a 12DW7 in V1 and V4. Put a 12AX7 in those two spots, will increase the gain significantly. Remember, a 12DW7 is actually a hybrid of a 12AX7 and a 12AU7, one stage is a low gain 12AU7 stage and the other stage is a high gain 12AX7 stage. So putting a true 12AX7 gives you high gain on both stages.

[olddawg]

V4s make great bass amps. The poor man's SVT. Can't you just pull out 2 output tubes and use an OD pedal and a dirt box (Rat?) along with the the MV option described earlies?

[Gtr_tech]

Big clean loud amps are just that. And trying to "get the old dog to do new tricks" is really not worthwhile. Just stick some kind of pedal or preamp in front of it and let the amp do what it does best.....make things louder.

[methodofcontrol]

thanks for the input, guys.
i'm with you. wasn't sure if someone had some ideas i hadn't thought of yet.
case closed!

[Chuck H]

These thing are so well built and designed. I just worked on one for the first time. It was a VT-22 (no distortion circuit) and the guy doesn't use it much. The tubes were old but not original and were in fine operating shape.. A couple of switches and tube sockets were dirty and it needed new power filters. I replaced all the electros for good measure and gave it a good cleaning. What an amazing amp. You said case closed but my $.02 says restore it. People seem to like these amps so your bud could sell it and get something he would love. Everyone is happy and you didn't have to hack the amp.

FWIW the Ampeg reverb design is capacitor coupled. So no cheap little OT crudding up the tone. It may be worth looking at a schem to see if your idea is more plausable with the Ampeg design. I would think so.