Mark III+ SRG

Got my Mark III+ SRG back from Mesa today. It sounds awesome with the + mod and the pentode/triode switch. Putting it in triode mode really sweetens it up. I think Mike B. said triode takes it down to around 15 watts but it's still loud. Pentode tightens it up and adds punch. I'm running it thru a Half Back 4x12 with C-90's on top and EV's in the bottom at 120 volts on my variac. It pushes the 4x12 with ease. I've got it loaded with NOS Chinese 12ax7's and Groove Tubes 6l6 GE's. The R2 mod makes it the perfect amp for me since I don't use pedals anymore. Mike replaced the reverb tank because a spring was broken so the reverb sounds a lot better now. I also had a fan installed since the chassis already had the hole for the fan outlet. I've got a stash of amber pilot lights so I have Mike swap out the blue ones.

Here's the pics:
https://flic.kr/p/2iCXxS4

https://flic.kr/p/2iD2HTs

https://flic.kr/p/2iD1hGM

Sweeet lil amp there bro. You are correct the amp gets down to 15w and still moves plenty of air, congrats!

Thanks! My ears are still ringing!

Installed a pair of Mesa labeled STR-387's in the SRG. The 387's really bring the amp closer to a c+. The clean's are detailed and bold. The overdrive is harmonically rich and smooth. In triode mode the amp gets close to a Simul c+.

So you have the +/++ mod?

The + mod.

So more gain but not the 20db. Sounds like you're enjoying it. I know they're the best amps on the market for the money. That amp there is clean to mean

The + mod makes the amp smoother and more vocal. The gain seems to be about the same as a c+. I had Mike B. reduce the brightness on my Simul III+'s so they're like the early Simul c+'s. My III Coli landed at Mesa today. Should get it back in a couple of weeks.

xdg999 said:

The clean's are detailed and bold.

Click to expand...

Did the mod effect Ch 1 at all?

The clean channel is warmer and smoother but still bold and punchy. My Simul III+'s cleans are softer and rounder. Next time I talk to Mike B. I'll ask him about the parts he changes that effect Channel 1.