Mark III Man
Member
Hey you Mark III heads, a question/querry on preamp tubes:
I first did a search (as not to ask redundant questions) and found some info on this to take note of.. It seems there are some mixed results with preamp tube swaps in the Mark III amps.
I have had other amps that 'voiced-up' radically different and those amps that didn't while swapping pre-tubes to dial-in my sounds. I don't know how the Mark III amps behave in this area.
I have a 'green stripe' '89 Simul combo that has a full set of ratty-looking, but still functioning, Chinese 12AX7 no-names... There's no marks or lettering on these at all, so I don't know if they are Mesa OEM or if some schlub stuck 'em in there in the past 20 years...
The amp sounds pretty good despite the Chi-Com AX7s and usually my motto is, if it ain't broke, don't fix it. My experience with these type tubes is that they are "servicable" and work OK, but can be a little bright, have a 'hard' voice and are usually thought to be generic-sounding.
If anyone has had good results with changing out the V1 slot and maybe the PI tube, I'd like to hear what you have done. I read a few posts where the V1, 2 and PI slots were changed to 12AT7, but I don't really want to reduce the R1 gain and would really like to chunk it up a bit with a more fat-sounding pre tube as long as I don't get a microphonic symptom when I switch to R2 or Lead modes..
To me, the R2 and Lead are pretty much there-sounding, but I'd like to fatten-up that R1 with more low end and mids if I can do so. I don't think the Chinese AX7s are helping R1 in this regard. I have always found them to be a so-so 'clean' channel preamp tube...
Any ideas from the Mark III heads out there??
Thanks,
Brian
I first did a search (as not to ask redundant questions) and found some info on this to take note of.. It seems there are some mixed results with preamp tube swaps in the Mark III amps.
I have had other amps that 'voiced-up' radically different and those amps that didn't while swapping pre-tubes to dial-in my sounds. I don't know how the Mark III amps behave in this area.
I have a 'green stripe' '89 Simul combo that has a full set of ratty-looking, but still functioning, Chinese 12AX7 no-names... There's no marks or lettering on these at all, so I don't know if they are Mesa OEM or if some schlub stuck 'em in there in the past 20 years...
The amp sounds pretty good despite the Chi-Com AX7s and usually my motto is, if it ain't broke, don't fix it. My experience with these type tubes is that they are "servicable" and work OK, but can be a little bright, have a 'hard' voice and are usually thought to be generic-sounding.
If anyone has had good results with changing out the V1 slot and maybe the PI tube, I'd like to hear what you have done. I read a few posts where the V1, 2 and PI slots were changed to 12AT7, but I don't really want to reduce the R1 gain and would really like to chunk it up a bit with a more fat-sounding pre tube as long as I don't get a microphonic symptom when I switch to R2 or Lead modes..
To me, the R2 and Lead are pretty much there-sounding, but I'd like to fatten-up that R1 with more low end and mids if I can do so. I don't think the Chinese AX7s are helping R1 in this regard. I have always found them to be a so-so 'clean' channel preamp tube...
Any ideas from the Mark III heads out there??
Thanks,
Brian