Tube rolling McIntosh c2600 preamp?

Real simple if you have stock valves, change them, they are BAD..
I've had 50 years with Mac.. Amperex, Tellies, Good RCA if you can find them. PSVANE is a great new option. The stock valves Mcintosh has used for the last 20 years are just cheap...BIG improvement, if you don't notice an improvement, don't spend a lot of money trying to find it..
YOU may not be able to hear it.. Some can some can't. Depends on your hearing. You don't need to change them all, just the pair in the mains to start (AUX) unless your using the phono section.. Amprex, Tellies, Volvo
PSVANE, Mazda, RCA (be careful with RCAs) some Sylvanias (bright).

BTW I use C8,11,20,22,2500,MX110 on the valve side.. I have  few of their SS models too. Good stuff...

Regards

With my Mac C2500 and MC302, I have a very deep and wide soundstage that goes way beyond the speakers. I am using the stock McIntosh branded tubes (new), with are JJ’s. I tried a quad of matched NOS Gold Lion 12ax7 which were graded as “uncle Kevvys stash” from Upscale Audio. After using them for 4 months, I went back to the stock tubes which to my ears gave me more of what I was looking for.

I chose the Gold Lion because that is what almost everyone in the Mac group on Audio Aficionado loves and recommended. I haven’t tried other brands as I am satisfied and it’s a PITA to remove from rack, disconnect everything and carry to kitchen table to unscrew all the screws.

agree very much with goheelz above - it is most likely a room/speaker/speaker placement issue

i have rolled tubes with various equipment, never have i found it significantly altered width of the image

If you want a little nugget for Mac, don’t use Golden Lyon, for signal valves. Mac used GL to voice MC275, but only their power valves, but never their signal valves. Mac used Tellies, Amprex, (Mulards), RCAs (if you can find BP), Volvo. PSVANE is a GREAT valve, and getting better.  The stocks valves, are ok at best, like JJs. They are probably the better of the bunch, top to bottom, for cheapos.
Like I said, if you can’t hear the difference, don’t waste your money. Some can hear the difference, some can’t.

Swap to Sylvanias, if you can’t hear that difference, you know.  But, you have to be honest with yourself. They should blister your ears, if they don’t in any Mac 1959-2020, there is a hearing issue, with a health Mac. Unless you don’t use a tweeter. 

Regards

Thanks to all,I'm not certain that my issue is the tubes but not certain i can rule them out yet for a couple of reasons not worth going into yet. I plan to call McIntosh later this morning for info and i'm sure they will be helpful.
@goheelz Sorry for the omissions, my current setup is as follows:McIntosh MC 452 amp and C2600 preamp.Cambridge audio azur 451 CD player being used as a transport, with SR blue fuses and empirical audio Synchro mesh reclocker, using the DAC in the C2600 because it was there and sounded better than another rated A DAC, i tried. PSB imagine T3 speakers. VPI Classic 4 turntableand finally a Power Plant Premier line conditioner.

I agree that the room and setup could be the bigger issue, my speakers are 391/2 inches from the side walls to the tweeters, the speakers are 6.85ft from the back wall, there is 8.25 feet between the center of the speakers and there is 11 feet from my seat to each speaker. You may be able to relate but lately I have been moving things around and listening to the system and room but not enjoying the music as all. As a music lover enjoying live music for over 60 years i find myself missing the joy and therapy that music has given me. I've been through this before and sold my stuff only to eventually relapse.
Thanks for your courtesy and consideration.Joe