Mk III and Mesa SPAX7-A preamp tubes

[Russ]

I bet you could get better tone than that. That seems like someone was trying to keep the tubes all Mesa and use their best in every position. There isn't anything wrong with what you have there. I wouldn't run all SPAX7's though. You can get better gain from a better selected tube and keep the microphonics jsut as low as well as get better tone from a tube that just inherently sounds better. Just my .02

 

[Restless Rocks]

The SPA's are great if you play cranked and have a lot of ringing problems but they are a rather neutral sounding tube. I have a set of SPA's I tried back in the late 80's and they are just as strong now as then. They will probably outlast a lot of the better sounding modern alternatives. That's the problem nowadays most of the really good sounding 12AX7 types don't last very long.