V 35 Tube Swap

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New member
Oct 27, 2022
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Looking to tame back the lead channel of my V35 for what I do. Even in the MK IIC+ setting it's got just a bit too much gain for what I'm doing these days. (can't believe I'm saying this, lol!) This is a backup to my 5:50+ combo and I've hauled it around to smaller gigs since it's smaller and lighter than the 5:35. I'd like to swap the V1 out with a 12AT vice the 12AX that it has. Question is, which one is the V1? Also, anyone know if this will do anything to the clean channel? I've seen other threads that talk about this where it may affect the clean channel on certain amps. (I think it was a TC on thread I read it on) Love the amp, just don't need all the drive it has and want to use it as a 2 channel amp like my Express. Thoughts?


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Well-known member
Feb 2, 2014
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You can download the manual from here, check out Page 50. It would seem any tube you replace for Channel 2 will also affect Channel 1. Each 12AX7 has two independent halves designated A and B. The tune chart on page 50 of the pdf manual states which function each tube half has, as well as a map of where they are located. It looks V2 might be uour best bet to change but it will affect channel 1 crunch a little bit.

Changing V1 tube will have a big effect on all channnels/modes if that’s what you want (some folks like to do this). All channels/modes use V1 as the input stage.


Well-known member
Jun 7, 2011
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I wouldn't use a tube swap to try to get the sound you're after. I'd rather spend some time trying to dial in the settings to something close to what you need instead - there's a ton of latitude in each of these channels, you can probably find the ideal amount of overdrive you need if you look hard enough. Make sure you don't neglect the xtreme channel for this experimentation - dial back the gain and it can sound really nice.

It was a bit of a disappointment that they decided to remove the drive knob from the Mark V's - that is one of the key ways to shape gain tone on the mark IV and earlier amps. In fact I asked them about this when the V first came out, and they told me that the current gain knob is actually the old drive knob, and that they had "preset" the gain knob internally to about 7 or so - testing this with a number of users it seemed to work the best (so they said).


Dec 23, 2022
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I've gone down that rabbit hole of swapping tubes. All I got out of it was a pile of expensive tubes I'll more than likely never use and a much, much lighter wallet. The engineers designing amps at Mesa do what they do best.
IMHO you need to just sit down and mess with the amp a little more or possibly a lot more.
But then again, if you insist on tube swapping. I have a bunch of tubes I'll sell to you so you can find yourself in my position😋