Cheap tubes

[edo1123]

I found some preamp made with 6j1 tubes. Now, those tubes seems to be cheap so I thought to build a sunn preamp around one or two of these tubes. Is it possible to use them as a 12ax7 tubes (I know the pin out is different, but I know nothing about tubes) or is not even close to be used in pedal application?

[Travis]

The 6J1 is a pentode, the 12AX7 is a dual triode

[balazs.bencs]

I found that most Chinese tubes (even TAD ones) are pretty microphonic, but the JJ tubes that I used in my amps are pretty good, most of them are non-microphonic at all, and I think that is kind of important if you're going to build a preamp.

I also had good experiences with some NOS Russian military tubes, but those can be hard to find and there are lots of different ones.

[edo1123]

Travis: could I use four pentode as triode to simulate two 12ax7?

Balazs: do you think those tubes are microphonic too? I read people buy the full preamp and sharing positive experiences.

[balazs.bencs]

well... The only problem with them is consistency. If you're lucky, you can find one that's not microphonic and works great, but if you're not lucky, you'll have all different sorts of issues. You cannot be entirely sure.

To be honest: I am saying this based on my tube amp experience. When I had Chinese tubes in the first preamp stage in amps, I had a million issues. All of those issues went away when I changed to JJ and never had a problem since.

[Gabi Smith]

If you want a cheap 12ax7 with an another pin out, try the nos russian 6n2p. I find they sound good. The rocket printed on is rather sexy.