Retube 12AX7 for Mark 2C+ question

Does anyone know the make of the 12AX7 tube I found in the V1 position on my 12AX7? :?:

It is in my avatar, and it has no markings except an "8" on the bottom near the pins.

I am considering trying some other 12AX7s to see how it changes my tone, like a raytheon/RCA/GE 12AX7A, and want to know how they compare to the mystery tube in my V1.

Also, should I need any special tube for the Phase-Inverter socket?

It's a tiny pic but it looks like a Chinese 12ax7 to me. Whatever tubes you get make sure they're tested for gain and noise, V1 in particular should be high gain and low noise, the phase inverter should have balanced triodes too ideally.

haha! voting early sure skews the results! 50% use the Sylvania

The tube in the avatar appears to be Chinese.

212Mavguy said:

The tube in the avatar appears to be Chinese.

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Definitely!

Sure - let us know what you notice in the V1 comparisons.

I don't have that same amp, but I have a variety of tubes in V1, depending on the amp:
1956 short black-plate Sylvania 12AX7
1959 long-plate Mullard f92 12AX7
1961 long black-plate Raytheon 12AX7A
1954 black-plate GE 12BZ7
1955 3-mica black-plate GE 6072A
1951 Ken-Rad long black/silver-plate 12AX7

The phase-inverter can be quite influential, depending on how you use your amp, and if you change to another type. For instance, using a 12AT7 in place of a 12AX7 can be a change you like. And then going to an E180CC (7062) from a 12AT7 can be just the ticket. Or going the other direction - from 12AX7 to 12BZ7. Heck - there's a lot of interesting combinations that you can try out. A/B test, and choose your favorite, then A/B test again.

- Thom

Timbre Wolf said:

But I'm confused - what are we voting on?

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I am just trying to see what everyone uses in their V1 position so I can determine what I should use there. Sorry for any confusion. :?

I replaced all my tubes with a Stock Mesa 12AX7A and I notice a massive difference in sound. Tighter, not as warm until the tubes warmed up for 15 minutes for the first time. (is that possible? or were my ears adjusting? or am I going crazy?)

TyeJones said:

Sorry for any confusion. :?

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Sorry - my confusion. I could not read the poll question while composing a reply, and I was trying to figure it out by reading your text.

Hey - trust your ears! Don't let anyone else convince you you're not hearing what you think you are, or try to tell you what you should be hearing. Life's too short to let others define your perception

- T

I replaced all my tubes with a Stock Mesa 12AX7A and I notice a massive difference in sound. Tighter, not as warm until the tubes warmed up for 15 minutes for the first time. (is that possible? or were my ears adjusting? or am I going crazy?)

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I noticed it too. I don't think we get use to it or that we're crazy!!!!!!.
I read on Doug's tubes website that the tube that he's selling are burn before shipping. It seem's that it changes the sound because it burn the gaz... in it. I think that's what happen with tubes that are not burn before shipping. We have to warm them before it gets ok...at lease, when they are new.
I'm surely not an expert but it make sense to me and my bassman hear the same thing too!!!!

TyeJones said:

I replaced all my tubes with a Stock Mesa 12AX7A and I notice a massive difference in sound. Tighter, not as warm until the tubes warmed up for 15 minutes for the first time. (is that possible? or were my ears adjusting? or am I going crazy?)

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I think there's a point at about that time .. 15-20 mins .. where tubes begin to come into their own. I usually wait until after they get a good warming before fiddling with the controls too much.

Timbre Wolf said:

Hey - trust your ears! Don't let anyone else convince you you're not hearing what you think you are, or try to tell you what you should be hearing. Life's too short to let others define your perception

- T

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big plus 1 for what T-Wolf said. Yes. Trust your ears, only you can decide how to shape your tone. What ever tube you decide for that #1 slot, get one with matched/balanced triodes. Same for #5.