Tube Brands

There are quite a few brands of tubes on the market right now which are current production and many are quite different from one another. In our guitar equipment (Marshall 4 input 50 watt tops) for preamp tubes I generally use the JJ 12AX7 and the Groove Tubes "Mullard" reissue for the driver. For output tubes in those amps I've been using the Saratov KT66(Groove Tubes KT66HP) which is no longer available. Right now we've been testing the Chinese made KT-66's that are sold by Valve Art which seem to be pretty similar to the KT66HP. They are a little brighter and seem to break up a little nicer actually but they don't play clean quite as well maybe but the differences are pretty subtle.

In the past we used the JJ E34L's with great results in the Marshall amps and until recently I used them always in Robby's Sovtek Mig 60 amp. Right now we're trying the Electro Harmonix 6CA7's in that amp with better than expected results. We've also experimented with a Sovtek EL34 and an Electro Harmonix KT88 in that same amp.

Sooooo, the big question is what sort of tones are you looking for? If you're using a master volume setup to get your sounds where most of the tone is generated by the preamp I would get a few different 12AX7's and experiment. The differences will be subtle for the most part but you can fine tune the sound and learn a lot. A Sovtek 12AX7 A or B tends to be rather colorless but not bad sounding and if the amps circuit is designed with them in mind they can be just fine. Also they tend to be trouble free for a very long time.

A Chinese 12AX7(easy to spot has the shiny metal piece between the two sections) can sometimes sound very good. They tend to have a slightly softer distortion tone in my opinion than the Sovtek and they tend to have more gain and sometimes more output too.

The JJ's seem to me to be the best overall in that they have lots of output, reasonable gain and a good all around tone. They can sometimes be noisy if the amp has a lot of gain but they are worth trying.

I've tried the Electro Harmonix 12AX7's and I didn't like them very much. I also have some old RCA 7025's and 12AX7's that I like to use in old Fenders and stuff and they tend to really work in those amps but again they will tend to be noisy and microphonic in a high gain situation.

There are many others Sovtek 12AX7LPS(sometimes cool), Ei 12AX7's from Yugoslovia can be bright sounding and pretty nice if you can find a good one, the list goes on and on......For a few bucks you can have a lot of fun with this stuff.