Rolled some tubes to try to make the Mark V 90 channel 2 more to my liking.
Slots:
- V2 - Ch2 2nd gain stage. Only one half of the tube is used and the other just does nothing. I wish Mesa had used the other one as a switchable gain boost or something.
- V3 - Ch2 4th gain stage
- V4 - Ch3 4th gain stage and reverb driver tube
Out:
- V2 - Groove Tubes GT12AX7M. This was their Mullard copy back in the day, but it suffered from reliability issues.
- V3 - GT12AX7M as well.
- V4 - Svetlana 12AX7. This tends to be a smoother, a bit less gainy tube.
In:
- V2 - JJ ECC803S long plate. This would be great in the phase inverter slot but I think one side of it is busted because last time I tried using it, it randomly cut out. I hope the side that works is the one used by ch2.
- V3 - TAD ECC83WA
- V4 - TAD 12AX7-C
The end result is that the amp cuts better and ch2 has more gain and brightness to it, which pushes it more towards the Marshall territory I want out of it. Ch3 with bright switch on is just about perfect for the kind of tone I want, so Ch2 falling just a bit short has bugged me for a while.
I swapped V4 by accident as I forgot V2 and V3 are arranged in an odd way. Lucky accident, because the reverb sounds better to me now.
I think the tubes I had were just too low gain and smooth sounding to work well. Or they're just old and busted, I don't have a tube tester!
I do still wish Mesa had put a bright cap and switch on ch2 rather than the largely useless Mark 1 normal/thick switch.
