Class A on Mark 3: normal to have more grit in cleans?

[Whoopysnorp]

My Mark III blue stripe is so loud that with the master just past 1, it's loud enough for my band (we use pre-recorded drum tracks through a PA rather than a real drummer, so we don't need to be that loud). This is through a Recto vertical 2x12. I was just messing around with the class A setting to see if I could tame it a little, but I found that my clean sounds suddenly had a bit of breakup to them when I changed the power class. Is this normal? I'm using 6L6s in all sockets.

I wound up changing it back to simul-class...it seemed more like 'my' tone, even if it is almost unmanageably loud!

 

[DrBazooka]

Hey!
How old are your tubes? When I bought my Mark III I had problems with the class A sound before switching to new tubes. I although use EL34 in the outer sockets since that is what Mesa recommends. I assume that you have tried to tweak the controls to improve the sound in class A mode. Boogies are loud and you can make a Marshall user crazy when turning up the volume. I rarely have the Master volume on more than 3 when playing live.
DrBazooka

 

[kmanick]

When I got my Red sripe I switched the "El34's" out to KT-77's and it really helped smooth out Class "A"
I still get the "blended" effect of 6L6's and El34's in simul class it's just a little fuller sounding.
My cleans in Class A with the Kt-77's are definitely better than with the El34's.

 

[Whoopysnorp]

I'm not sure how old the tubes are. They're Mesa-branded and were in the head when I bought it on eBay. I actually didn't try to do a lot of tweaking. Here's the issue: I have kind of a weird setup. I use this blue stripe head and a Studio Preamp in a 6-space rack. The output of the Studio Pre and the Mark III's effects send both go out to an A/B box on the floor, the output of which goes back to the Mark III's effects return. This way I can switch between preamps on the fly. I try to get kind of a pushed clean sound on the Mark III R1 channel, which makes it pretty loud. I have to get the output level of the Studio Pre pretty high to match this volume. I am pretty sure that the grit I was hearing was a result of the class A mode not being able to handle the output level of the Studio Pre cleanly, while simul-class mode can handle that, for whatever reason. Thus I doubt I can tweak this away without screwing up all my carefully-balanced settings.

 

[MrMarkIII]

Class A is 15 watts, Simul is 75, so less headroom before breakup in Class A. You'll get a cleaner R1 by reducing Volume and turning up the Master.
Doesn't "pushed clean" mean the same as "more grit in cleans"? What's the diff?
You could also reduce stage volume by using a 1 x 12, and/or a less efficient speaker.

 

[CoG]

+1, if you're playing that quietly get a 1x12, that will make a bigger difference than anything else in making your tone and volume manageable.

 

[Whoopysnorp]

Doesn't "pushed clean" mean the same as "more grit in cleans"? What's the diff?

I am going for the grit on R1 of the Mark III, but want a nice sparkling clean on the rhythm channel of the Studio Pre.