Conn Caprice 427 needs new 12AU7 tubes—advice?

[Firepowerforfreedom]

My old Conn Caprice 427M is in need of repair (and has been that way since I picked it up from Goodwill). Its great and swell tubes are pretty much shot, so they need to be replaced.

Any advice on what tubes I should buy, and if I should buy new or used?

Thanks,
FFF

[nigelwright7557]

I always buy new tubes so I know how much life they have left in them.
Ebay tubes could be close to the end of their life despite still working.

[Firepowerforfreedom]

Hmm, after a little investigation, I found that the tubes aren't really as shot as I thought they were. Turns out a pin had fallen out, breaking a circuit and disabling a lever that controlled the great's bright/mellow timbre. After replacing that pin, the whole organ seemed to come back to life. Weird.

There's still an issue with the pedal controlling the tremolo rather than the volume, but I'll post that to a different forum here.

Removing all the tubes carefully with plastic gloves, wiping the dust off them with a dry paper towel, and then reinserting them seemed to kill a loud hum the organ made. It also brought the volume up from a measly mumble to a wonderfully melodious shout.

Some of the tubes are still having problems, though, so I think I will buy a few new tubes. Would you recommend going on the cheap side or shooting for the more-expensive tubes?

[mashaffer]

I would recommend cleaning all switches, sockets, pins, pots etc before replacing any tubes. IMO Tubes are way down on the list of possible bad actors. Of course if you have a stash of tubes to swap in go ahead. I also wouldn't spend a lot of money on the tubes if you do end up replacing some. Not talking about an audiophile preamp after all. Just my take.

[bob91343]

I feel that a tube is a tube. The manufacturer meets the specifications so that should end the discussion. Further, tubes will probably outlast most of the other components if they aren't abused.

It appears you may have some marginal tube sockets, however. Rock the tubes in their sockets and that could fix a lot of problems. It certainly cured all the problems my old Ampex tape deck had. Finally, run them through a tube tester to remove doubt.