Ampeg V-2

[rictified]

I'm not sure Greg, I haven't really messed much with it, it has a bias adjustment like most Ampegs though. It came with two really old GE 6l6GC's in it now that test at about 20%, so I decided to buy some new ones and bought Sovtek 6L6's and put them in without touching the bias and the plated glowed cherry in one of them, haha! Also the GE's were much louder, bassier and punchier at the same volume setting, I now believe in NOS tubes. I can't believe the difference. I'll try out your formula when I have some time, thanks and I'll let you know. BTW it wasn't the preamp tube it was a voltage regulator tube 0C3 that had a broken plate wire that was touching some times and not other times.

[soundmasterg]

Hey Bob. NOS tubes usually will put out more current than new stuff, whereas new stuff puts out more gain sometimes. Current is more important to power in some ways than gain is, so NOS stuff often gives more power. The metallurgy and vacuum in NOS is usually quite a bit superior to new stuff since tubes were a big buck business then. Nowadays they can't be bothered as no one would pay what it would cost for tubes of better quality to make it profitable for the manufacturers. All of that said, the Sovtek 6L6 isn't a particularly good tube, and I'm not surprised it had issues. The Sovtek 5881 is a good quality tube, but not a real 5881 and sounds bland to most ears. The EH stuff is pretty good, as is the JJ. Most people like the SED or Winged C 6L6GC (formerly Svetlana in the US, still Svetlana in the rest of the world). They sound very good and are very well made for new tubes and last well. In my experience, they are the best new manufacture 6L6 type for quality and sound, but YMMV. I've run into the same thing you have with regards to NOS. In my Vox AC30, I really like GE EL84's in there, but they cost a LOT and are getting scarce. They GE's also last about twice as long as modern tubes. But, since they are so hard to get, I use EI EL84's in there which sound almost as good, and are a LOT cheaper, and last pretty well. I want to get a GE EL84 quad to use for recording one of these days....you may consider the same for your ampeg and use new tubes the rest of the time.

Also, you should always set the bias when putting new tubes in. Set the voltage to max negative voltage, which would make it least amount of cathode current. That way you are sure the tubes will function. Then you adjust the bias current up (voltage down) until you reach a level the tubes are happy with. Sometimes with older amps, they only have bias balance or non adjustable bias, so that complicates things a little. Good luck on it.

Greg

[rob]

I can't believe someone just bought one for $800 on eBay. I'm not sure they're worth that much.