Tube Brands

[jrichview]

I have a Mk3 Simulclass and I've heard a lot of different stories on what brand of tubes to use. Mesa, naturally, insists you must use Mesa tubes. That's what I've been doing for a long time. But I've been having a problem with spotty quality with some of the 12AX7s (including the "specials").

What brand do you use in your Mesa?

 

[tony777]

You don't need mesa preamptubes. The myth about mesa amps needs mesa tubes comes down to fixed bias which only has anything to do with powertubes. With a bias probe you could easily measure the draw of the powertubes and use whatever brand you like. The thing about it is that if you buy mesa powertubes, they are already in the range of what's recommended for the amp.

 

[jrichview]

You don't need mesa preamptubes. The myth about mesa amps needs mesa tubes comes down to fixed bias which only has anything to do with powertubes. With a bias probe you could easily measure the draw of the powertubes and use whatever brand you like. The thing about it is that if you buy mesa powertubes, they are already in the range of what's recommended for the amp.

Thanks for the reply!

I wouldn't know how to do that, never having really understood how tube bias works. And I get tubes mail order so I'd need to know how to select them without being able to test them first.

I'm just wondering if anyone has positive experience with particular brands?

 

[lowercasee]

My Mark III has JJ 12Ax7s in V1 and V5 and it sounds great to me. With preamp tubes, you are pretty free to experiment with whatever types of tubes you like.

 

[gts]

With preamp tubes, you are pretty free to experiment with whatever types of tubes you like.

+1

Since bias has nothing to do with pre-amp tubes you're free to try out any and every 12ax7 out there.

 

[kippiejr]

Best advise for sure is to find a preamp tube tester. The best preamp tubes in any Mark amp are the ones that reads as its designed. At, near or above 100mA. I can't tell you how many pre amp tubes I have purchased that have not read as advertised. 12ax7's are like 2 tubes in one. Marks run any where from 4 to 5 of them. Any one of those triods are low/bad your tone will suffer. It will suffer every time in V1. I have seen brand new JJ's Mesa,EH, GT, Ruby,Tungsol..etc.......any where from 60mA to 80mA as a new tube.. If you never knew and that tube ended up in V1, you would never know what you Mark amp could sound like. I will say The SPA's rarely come in bad, but it has happened. If you can find a tester that test microphonics it really helps trouble shoot. My 2nd V mini had a bad squeal at high settings right out of the box. I knew something was up since my 1st did not do this. Turned out V4 was microphonic and replaced it with a like tube (mesa) which are JJ's and problem solved. Mark amps are hard on preamp tubes compared to other amps. Especially V1, hence the extra tube when you bought a II or III back in the day. After years of tube rolling, I came to a conclusion that it wasn't really a brand thing that made the amps sing, rather the quality of the reading.

 

[Buster Leggs]

What preamp tube tester do you recommend? I've been thinking about this issue for a while.

 

[stokes]

100ma's???A 12AX7 tube that draws anywhere near that will explode.1 to 2ma's or so for a 12AX7. The best test for microphonics is to tap it with your finger or a pencil while the amp is on,even good tubes will make a little noise thru the speaker in a high gain amp,like Mesa.I know of no commercially made tester that gives a reliable test for microphonics.