mosriteforum.com

What brand of 12Ax7 tubes has the highest gain, bright sound and low noise ? (for a Mesa V-Twin pedal).

Brand should not have much to do with the gain. Gain factor for 12ax7 = 100%...12at7 = 60%...12ay7 = 45-50%...12av7 = 41%...12au7 = 19%. The gain factor of a tube is how much it amplifies the signal.For what I think you want most any good 12ax7 will do fine.

You might want to check out this link. It has a ratings of various tubes. http://thetubestore.com/

I've used these guys before http://www.watfordvalves.com. They know their tubes and their characteristics inside out.

If you can, find old pulled 12ax7's from 50's -60's amps, they are for the most part superior to what you can buy new today. Preamp tubes do not wear out nearly as fast as power tubes. Heck, you're usually better off with used power tubes from 50's -60's too. The old ones are far less microphonic, warmer sounding, less harsh and very often have a higher gain than new ones. I was at Victoria Amp one day and the owner was trying out a new amp he finished and the new tubes were rattling. He put in some used, 50 year old power tubes which not only didn't rattle, but sounded far better too. I find that the old tubes in vintage amps I buy are much better sounding than most new ones. You'll pay more for good new tubes, such as Tube Amp Doctor(TAD), but they are worth it. If you're on a budget though, go with the old ones, buy as many as you can and use the ones that sound best, and try them in different positions in the amp. You'll be surprised at the difference you'll hear. Good luck,

Rocco

I have been using Tung Sol 12AX7 in v1 and v2 in my Twin Custom 15 for the last 4 years with no problems. I also have TAD 6l6's for the power tubes. I tried some jj long plate 12ax7's but they went microphonic in just a few month's.

Jim

tubes can be confusing sometimes because there's really only a handful of manufacturers, and usually a company slap another name on a common tube, and you think there's 15 different choices when realistically there's closer to 5. Groove Tubes is one example of this. What makes it worst is if you like groove tubes for example, it's possible that a groove tube could be made from one manufacturer to another in any given number of years.
I pick Svetlana for my amps, but that's just me. It's suppose to have the least amount of noise with the highest amount of gain, but who knows, I could be totally wrong. 12AX7's really are pretty cheap (unless you buy an old one) so have at it.

There are only a few companies actually making tubes, however, they do make them to spec for different companies, like Tube Amp Doctor(TAD) and others. Groove tubes does make some tubes, I think 6L6's, on the original tooling from RCA(?), not sure. Groove Tubes also does a pretty good job of grading power tubes for levels at which they distort AND for bias matching. Basically bias your amp with a tube you like and just buy the same grade when replacing. They also grade their 12AX7's and you can get pretty much any manufacturers tube from them. They grade and then put their stamp on them.

There are some very good new tubes out there, I still like old ones best. And always put your preamp tubes back in the socket you pulled them from once you get ones you like. Your preamp stage, makeup stage and phase inverter all operate at different voltages, react differently and have a tendency to "burn in" at their specicfic location. But don't be afraid to experiment till you get the tone you want.

Rocco

Thanks to all who responded w/info. I put in 2 Electro harmonix 12AX7's in the V-Twin and the gain is perfect with low noise. Perfect for gigs with a back line. No lugging the half stack.

last I heard, I believe all groove tubes were made by another company. I think it was tesla.