Calling all MC275 MK IV owners..............

I just set up my new MC275 and although the tubes have about 90 minutes on them, I'm blown away by the sound - I wish I discovered tubes 10 years ago.

Anyway, a few questions:

1. What gain level do I set the amp to. I cranked it all the way up but is there an "optimum setting?" I'm running these in stereo mode with unbalanced connections.

2. In a couple of days another MC275 gets delivered and I plan to run them in mono mode also using unbalanced connections. What gain setting is optimal for that configuration?

3. I have the amps on a trigger switch and noticed that on power up the tubes sort of glows a bit brighter for a second then settles back into the normal orange filament glow. is this normal?

4. What is tube rolling?

Thanks for all your help. I really appreciate it. Sorry if these questions are a bit stupid.
hi pookie.

tube rolling is just trying out different brands & types of tubes.

the glow you spoke of is normal & after the tubes break in they will settle down.

there isnt a optimum setting for your gain controls but you can use them to your benifit,i set my gain to where my max listening volume is at 100% of the volume adjustment on the preamp.

you cant hurt your amps by running the gain any old way you like so just have fun & enjoy your new gear,the new class of mac amps are amazing & i get a ton of enjoyment out of mine too.

just out of curiosity what preamp are you going to run with the 2 mc 275's & whats the rest of your rig.

Thanks for your answers. I think I will just relax now. The rest of my system is:

B&W Nautilus 804 (MC275 will drive these), HTM2 center and a pair of SCM1s.
I'm using the MIT Magnum 3 for the fronts and cheapo wire for the rears.
All hooked into a McIntosh MHT20 via Synergistic Reaseach Designer Reference interconnects.

I'm at a crossroads where I have to decide if I'm staying with 5.1 or going back to dedicated 2-channel. If I went back to 2-channel I would get the C2200 pre-amp but I'm concerned that tube on tube might get to sonically hazy or muddy.

To be honest, I'm pleasantly surprised at the MHT200's performance as a stand alone pre-amp. Granted my expectations were low to nil but it would stand up against many dedicated pre-amps.
Don't worry about tube on tube getting fuzzy or hazy. I've been running like that for years and years and with the right equipment, get magnificent music making. Just last night I was listening to a Gene Ammons CD which sounded open, clear, and as if the band was right in the room. And this with a tube pre-amp, SET tube amp, and I am sure the original recording was done with all tube studio equipment.

Both tube and SS stuff nowadays (and going back a few years) can make beautiful music. There are tube designs which can sound a but fuzzy and hazy (older C-J stuff) and designs that can sound crystal clear and almost over-lit (Some OTLs). You have to check out each piece on its own merit.
i own the c2200 preamp & i love it,i ran a mc2102 on the c2200 & the 2 tube units paired up nicely,you shouldnt have a mismatch with the c2200 mc275 combo.