jeffm725 wrote:Couple things......
1)Flaky Reverb on these, after 3 tanks and the resistor mods, I said screw it and I use a Holy Grail Nano put right before the Amp input (and have run it in the loop as well, more on the loop in a minute, because the loop doesnt work as loops do now, and the mark 2a I think was the first, if not one of the first amps with a loop). The Nano, for GD material sounds great and better than the couple different tanks I had onboard. However, even if you dont use a reverb tank in that amp, keep a decent 12at7 in the reverb driver tube and make sure the reverb level on back is set to something, as it does still affect the gain in the signal path
2) You mentioned muddy:
CRANK the prescence on the back. Mine is set to between 8-10, depending on room. Try it all the way on 10, it will sound bright to you, but if you heard Jerrys amp out of band context it probably would have sounded too bright too.
3) Dont use the Second Channel, Lead drive, Lead gain, or lead master. Simply use the first channel which would be the firsts gain pot all the way on the left (cranked) and the first Master Volume. Push every other Push/Pull Pot IN (or make sure foot switch is set for channel 1 )Also, dont use the EQ, defeat it.
First 5 knobs is all you need on the mark2a for Jerry (and presence on back) , everything else other than that defeated.
Master Volume to taste (on a loud stage in 60 watt mode, I rarely if ever find the need for 100 watt, my master never goes above 3.5!)
What tubes do you have in there?
You want to think of this Amp like a Twin. Use it for its cleans and use pedals for dirt.
Thanks! I'll have to figure out what, if anything, I'm going to do about the reverb. I've run it through my Line6 M13 ('63 Spring Reverb) and that sounds pretty good, actually. Maybe it'll stick.
Agreed on Channel 2. Now that thing is just pure mud, like if I dial in Channel 1 just about right, it's basically impossible to switch to the lead channel and get a useable tone. Kind of a head scratcher.
I haven't looked through the preamp tubes, but power tubes are Mesa branded. Could be that it needs some fresh/better tubes.
After playing with it for a while, the Presence knob is difficult for me to get comfortable with. You're right, it can get very bright...but I can't decide if it's doing so in a way that I like. Seems to me there's some trading off between how high I have the mid dialed vs. how high Presence needs to go to kind of balance it out. I'll be fooling around with this one for a bit, I know.