what is the gainiest preamp tube??

[minorseventh]

"gainiest". I dont think thats a word.

I just got a microbaby and it rules. playing with tube combinations Im finding that the stock 12ax7 it comes with provides the gnarliest sizzle. I just bought a JJ 12ax7 that was supposed to be designed for high gain, and I dont know if its a dud or what, but it completely sucks....the balls right out of this little amp. ebay of course. I should have known.
anyway, I have a small collection of tubes Im trying, and loving most of the combinations, but I would really like to know which preamp tubes will slam the power tubes the hardest.
it takes 12ax7, 12at7, 12au7, 12ay7, 5751, 12bz7... maybe a few more I dont know about?

[6AM]

12AX7s are the highest "gain" preamp tubes. Chinese 12AX7s tend to sound pretty good for high gain.

[twangbanger]

Originally Posted by 6AM

12AX7s are the highest "gain" preamp tubes. Chinese 12AX7s tend to sound pretty good for high gain.

+1 on those and you might want to try a tung sol reissue, if you call Knos tubes or Doug's tubes and tell them what your looking for, they might also be helpful! Getting tubes off E bay can be a real CRAP shoot, usually not tested or screened or they might be off loading the undesirable tubes.Ive found both of the above mentioned to be the best source for me.

[John Phillips]

RFT (NOS). The fattest, dirtiest, highest-gain 12AX7 made, in my experience.

They sound best in Marshalls, if that makes any difference.

[go7]

+1 on the RFT [nos]. Enjoy!

[Blue Strat]

Yes, if you mean "lots of distortion" when you say "high gain" (which doesn't mean distortion), the NOS RFT 12AX7 is the way to go. It's a bit less bright on average too which could be a benefit or not.

When tubes are advertised as "good for high gain applications" (which would mean in a high gain amp that creates a lot of preamp distortion) it doesn't necessarily mean that they create more distortion. In some situations it may mean that it has low microphonics which are often a problem in "high gain amps".

[TheGuildedAge]

Love the RFTs for gain. I am actually back to using now tesla in my fargen olde 800 because I wanted better cleans.

But I love the RFTs in my mighty plex to get more crunch sooner.

[Gear91]

What about the EF86?

[rosssurf]

What is an RFT? ..please pardon my ignorance

[stratton]

Originally Posted by Gear91

What about the EF86?

I was wondering the same thing.

[FastRedPonyCar]

Someone at harmony central measured gain on about a dozen preamp tubes and the JJ's ECC83 had the most gain but the tone is blah from those.

[stvnscott]

If we are talking about 12A*7 types, I've found the JJ 803S to be the highest gain current production tube on the market.

Otherwise, the EF86 is hard to beat for gain, but extremely microphonic.

[Blue Strat]

Originally Posted by Gear91

What about the EF86?

Cool tube, high gain, but can't be used in a 12AX7 socket. BTW, gain has nothing to do with overdrive/distortion...it's how much amplification a tube provides. Hence, the EF86 doesn't provide distortion, it provides a lot of amplification.

[Blue Strat]

Originally Posted by s2amps

If we are talking about 12A*7 types, I've found the JJ 803S to be the highest gain current production tube on the market.

Gain (amplification) or distortion?

Otherwise, the EF86 is hard to beat for gain, but extremely microphonic.[/quote]

NOS EF86s, while still somewhat problematic, have much lower occurence of microphonic problems than the new production EF86s.

[stvnscott]

I was referring to amplification. Of course a few gain stages in series will produce distortion and higher gain tubes will get you there faster and give you more of it But I do know the difference

I'm not much of an expert on NOS EF86s, although it is usually fair to assume NOS is without some of the issues with new production.