Musicians and Gear

I retubed the Mesa Mark IV and holy crap it sounds good. It's a lot of amp, I don't really need it, and I really wasnt planning on keeping it for long but it's very inspiring to crank up something that is so well made...

Is it for the Behringer tube monster pedal?

What I have learned about that circuit is the tube is not actually producing the overdrive, because the pedals don't run at higher voltages like an amplifier, but they are used instead to color the tone and give it a more "natural" sound (as opposed to solid state tech that is often described as "sterile"). So, the best thing you can do for this application is find the cheapest, low noise tube. And, it doesn't have to be a 12AX7. Any 12AT7 or 5751 will work just fine. Tubes labeled 7025 are also great because those are just 12AX7s that have been either manufactured specifically to be low noise, or screened and selected from large batches as the ones with the lowest noise.

My new production picks for low noise without worrying about price would be TAD 7025, or Mullard CV4004. You might find that a cheaper JJ tube works just fine as well, but they tend to vary more. So ultimately the best are probably 7025 or any JAN tube (Joint Army Navy; Military spec tubes designed to be rugged and last a long time) such as a JAN-Philips 12AT7, but the latter can be pricey since they are no longer made.

Here's a long but useful link about different tubes: www.thetubestore.com/12ax7-tube-reviews
and here's a chart with noise levels from some (but not all) new tubes on the market www.thetubestore.com/12ax7-tube-reviews-chart
This chart says Sovtek and EHX tubes have the lowest noise. However, I take TubeStore reviews with a grain of salt though because they are inclined to rate highly whatever tube they want to sell, and because they have a house brand that competes with other companies that test and screen like TAD.

If you are not already having issues with noise or hiss, it could be that it doesn't change much.

Are any of y'all on the gear page? I read it but don't post

Here you go dude

I've been searching for tubes again lately. I already have an assortment of preamp tubes, 12ax7(3sylvania-baldwin branded, and 2ge), 12au7(2rca), and 12at7(pair of fischer branded Telefunkens). I bought a couple 12au7s before doing enough research thinking I needed them. I've been reading about rolling tubes in the micro terror, mostly to see if I can hear the difference. I'm seeing that using a 12at7 instead of the 12ax7 in the MT can have good results by taming the gain from 100 to 60. I never turn the gain up much on the MT. The 5965 is even lower at 47, I think I read. The 5965a has a 10000 hour life span. I'm going to buy a few different equivalents in the 12at7s and experiment with the micro terror.

I love that you share all this knowledge w us. I know nothing really technical about electronics , ive always just wanted to play and sing. but i really appreciate there are people like you who do. my older brother is like that he has an old 2' tape recorder took it all apart put back together . I was like "let me know when its ready." hes going to do the tube thing for me, next weekend .

Ever buy from Fuzz Audio? I ordered Zenith branded GE 12at7. Why even call it a Zenith branded tube if you are going to put a disclaimer that it might be a diffdrent tube? Lame.

I got it back out of the box, which is original and in excellent condition, and took a closer look. It was advertised as a halo getter and this one is squre. It was also listed as 95% print/label and this one is not anywhere near that. Oh well. He wants to send me a different one and is being cool, I guess, but it is annoying. After I told him I was just playing around with rolling tubes in the micro terror he also said the gain tested really high on the tube he sent. I want to be like, you mean 60, right? 60 rather than the normal 100 that the micro comes with, the 12ax7? Nans. There was a reason I had never tried any of his gear. Should have trusted my gut.