Sound — 6
OK, here's where it gets weird. The clean channel on this amp is excellent. In "clean" mode it's the highly though of Mark IV cleans. But in "fat" mode it's straight up blackface cleans. I could actually see country players buying these things just to have a 100watt blackface beast in their backline. But everything goes downhill from there. As far as I'm concerned, the gain sounds just were not up to par. With a total of 7 gain modes spread across three channels I'm not going to review them one by one, you'd think I could find something I liked. Nope. Everything sounded small, thin and nasal compared to other high end high gain amps I used and love (Budda Superdrive 80, CAE, Splawn Quickrod, Soldano, Rivera). I tried a variety of guitars - Les Pauls, an Anderson superstrat, a conventional strat, a frankentele, a Gibson ES-137. Some were OK, but at the end of the day every guitar sounded markedly better through some other amp I owned. One possible issue is the cab I was using - a Splawn 4x12 wired with Eminence speakers at 16ohms. Great cab, but there's no 16ohm tap on the Mark V. Per the manual, 16ohm cabs should be run from the 8ohm output jack, and that's what I did. But maybe the impedance mismatch contributed to the less than Stellar gain sounds. I tried the head with a Mesa 8ohm closed back 2x12 with V30s, and it was maybe a bit better, but I was still unimpressed.
Overall Impression — 6
At the end of the day I sold this amp at a loss and walked away. No matter how seductive all those knobs and switches are, if it doesn't sound right there's no point in keeping it. I'll stick with my CAE preamp and Soldano SM100-R or Rivera Hammer 320 power amps. I've played professionally for a long time and play whatever style of music people will pay me to play, but I bias towards country and lighter rock styles through 80's type metal. It's possible the "extreme" gain mode is the bees knees for heavier modern styles, but I kind of doubt it. If I had a modern metal gig, I'd take my CAE.
Reliability & Durability — 9
Randall Smith designs some of the most reliable amps ever produced. If I liked how it sounded, I'd gig the Mark V in a heartbeat. It's a tube amp, so there's always tube related issues of course.
Features — 8
This was one of the first Mark V heads made. In terms of versatility, the Mark V is unbeatable. There are 3 channels, each with multiple modes, each with a 4 band EQ, power amp control switches, independent reverb, and an independent post-gain graphic EQ. Basically, take all the knobs and switches you would find on a typical multi-channel, multi-preamp rack rig, Jam them all into one front panel, and that's the Mark V. There's a switchable effects loop (on a per-channel basis) too. On the output side, it's the typical Mesa Simulclass 80-100 watt power section from 4x 6L6s. The power controls allow that to be throttled down to 40 or 5 watts. In a baffling omission thought, there is NO 16ohm speaker tap. Just 1x 8ohm and 2x 4ohm. I know Mesa knows how to make 16ohm transformer secondaries, because they did it on the Tremoverb. But apparently the flagship Mark V doesn't merit one. More on this below.