#1
Note if I need to provide more info ask and I'll find it.

O.k. I mentioned like a month ago I got a Peavey 60/60 tube stereo power amp. Recently I finally got a splitter for my preamp and set it up to play through my two 1x15s. Sounded good, fiddled and jammed, fiddled and jammed, then I went to the liquor store and when I got back turned it on and fzzzzt pop *flash of blue*. I turned it off like a flash, but I assume a power tube and a fuse at least went kaput. The previous owner said this had old tubes, and they are at least 15 years old. In addition the volume pots are a bit janky from a old repair.

My mission now is to sell my superfluous gear and junk to acquire funds for funds sake, but also to get this thing back on its feet and ready for bass duty. I have a PDF of the manual and schematic on hand, for anyone who could help me with these questions.

1. The 60/60 and my preamp use some 12ax7's, I know 12at7 and 12au7's are the same virtually with less gain. I am wondering if I replace them with lower gain tubes will I still have the same 60 watts but with more headroom, or will the lower gain drop the decibels? The preamp isn't the actual power after all.

2. For the power tubes it uses some 6L6GC tubes, two pairs. I know it takes biasing and work, but could I replace them with say KT-88's? I'd need to check the actual unit to see if it has the real estate for that, but I am curious If the transformers, and other guts could handle a watt and power jump for some more headroom. Remember I have a schematic and manual with specs if you feel up to looking and checking.

3. Aside from wiring new pots into the amp, I kind of want to know If there was a way (mod wise) to say power up only one side so I don't have to always remain in stereo. And secondly if there is any possibility of wiring this to be bridged for 120 watts.

Again I have the info on the amp, and my Dad is an electrical engineer who can help me with the mods, but I like to get some research knocked out first. I paid $175 for it, and it's by no means a classic vintage piece like the name implies, so I am fine with changing it up.
#2
6L6 tubes and KT88 tubes are not interchangeable. You'd need some serious reworking of the amplifier's components to make that happen. As for the preamp tubes, stick with what the manufacturer recommends. "Interchangeable" often means different things to different manufacturers. As for running it bridged, I don't know if that one will do that. Download a manual and see if it says so. You can run one channel at a time in Mono. I believe you're supposed to use a dummy load for the unused channel. Again, check the manual and make sure.
"Maybe this world is another planet's hell?" - Aldous Huxley
#3
Are you talking about the 12ax7s in your preamp or power amp? Putting 12au7s in your preamp will get you a bit more clean headroom, yes. Can't tell you what the difference would be in your power amp though.
All your questions would be better suited for GG&A or GB&C imo. These kinds of questions get asked and answered over there a lot more regularly.
#4
Well, the pre has one 121ax7 for the driven channel. The power amp has a few rectifier for one at least, but unsure of the rest. I have asked in that area several times on various projects, but no one really answers me in a way that helps. I figured at least here maybe someone with guitar to bass and tube knowledge might be able to chip forth some.

on the little 5 watters like champ 600 I've read about people throwing a 12at7 in there and get more headroom at the expense of volume, which seemed weird and pointless to me as it seems there's a very small difference in loud with less headroom and less loud with more headroom, seems like you'd always be dialed in around 12 oclock-3 oclock
#5
I can't give you too much advice as I get a tech to handle the inner workings of my amps,but when I got my amp,it was running on 3 kt88's and a 6l6 that had been put in there when a kt88 had died (the kt88's were the original set,still said made in england on them!),so 6l6's can work in the same slot as kt88's,but obviously you want a full set of either and have them properly biased!
Once I got it back from the tech with a full set of new kt88's it had gained 30 watts in output (or atleast according to his measurements) without altering any other parts,so different tubes will give you more wattage/headroom,but it won't be a huge amount,so maybe you could get away with it?
Seagulls,the chicken of the ocean.

Originally posted by Gunpowder:
Everyone just jumps on the bandwagon and gives the same advice in these situations. You know what? I'm going to be different. Call the firemen.
#6
Big difference in going from 6l6s to kt88s as opposed to vice versa. I dare say the transformer in the Peavey wouldn't be able to handle the extra kick in the guts from kt88s.
#7
Peavey is tough stuff, I am of course speculating with all these questions and have realistic expectations. when it blew the tube, I had just got it everything zeroed in for a clean and gain tone and a good number of in between depending on how hard I used my fingers. For the money I couldn't find a tube amp for cheaper, and at this point I couldn't even sell it and make money with a blown tube. I figure if I can mod this even minimally to make it a real keeper might as well. I do want to at least hook up some LED's into the maw of this thing, the grating slits have a little tube light, but a red or green glow would be cool.
#8
Peavey might be "tough stuff" but it won't take tubes that it wasn't designed to take. Plate voltages and all that shit, I think. It's a guitar power amp, it doesn't matter that you're playing bass through it so go make a thread in GG&A.