I own a Vai Legacy 1 2x12 combo and can vouch for its clean channel. It is a very pristine clean sound, even with EL34s. I personally run 6CA7 tubes in the power section and there is much more headroom with those tubes versus standard EL34s. The dirty channel, though is noisy. There is a constant hiss. I have tried many different preamp tubes and nothing cleans up the hiss.
As Blaklynx stated, there is no true master volume and this amp is a very loud beast. I use a Boss 5 band graphic eq in the effects loop to help tame the volume by adjusting the output slider. There is a mod out there to install a true post PI master volume, and I purchased all the components to make the mod, but still have never done it. There aren't any really good amp techs in my area, so it won't be done until I can find one. The mids on the overdrive channel are a little off to my ears as well. Of all things, a Behringer Spectrum Enhancer really helps dial those in. I have been trying to sell mine for a couple years and no takers, so now I just leave it at my practice place. It's also a heavy *******, too, but not as heavy as my Road King 1. For those that say the overdrive channel isn't high enough gain must be looking for a nuclear holocaust tone. I play a range of material from the 50s through today, and the only tone I can't nail is a rectified tone. I can nail Judas Priest (pre ENGL years), Boston, Foreigner, ACDC, Jet, Green Day, any classic "Marshall" tone. I can even add some bottom end balls to emulate Volbeat. Aside from the hiss, the overdrive section is much better than other reviews I have read. I rarely push my gain past 2 o'clock.
If you want to stay in the Mesa family, the Road King 2 has the Lonestar clean section, which is supposed to be the best clean Mesa has ever produced. I can say that the cleans in my Road King 1 are outstanding to my ears, so I can't imagine how the RK2 sounds. When I was in the market for my first Boogie, it came down to the Lonestar or the Electra Dyne. The Dyne won me over in the end because of the Fender clean section and the "Brit inspired" overdrive section. The Dyne, though, is in a class by itself, much like the Lonestar. Neither of the two are considered "high gain," but I overcome that with the addition of an Xotic BB. For the material I cover, the Dyne fits my taste and style perfectly. I use EL34s in the Dyne, so the cleans aren't as pristine as they would be with 6L6. I have toyed with the idea of using the 6CA7s for the power section, but since I started using Tung Sol EL34s, I just can't bring myself to change. I do more on Vintage Lo than any other mode, so I am not as much concerned with the clean section. For what it's worth, using the BB has added a fourth and fifth mode to the amp. Using it with the clean mode gives me an awesome dirty blues tone that is exactly what I was looking for. Using it with Vintage Lo allows me to get ACDC lead tone. Turning the BB off in Vintage Lo brings me back to ACDC rhythm.
That was a lot of rambling. I hope some of it helped.
Good luck in your quest!
