You've got to be kidding me. I can't believe the grief this unit has recieved in here.
Learn to tweak an amp, much less USE it before you review it.
If you pair this preamp with a shitty power-amp, you're gonna be disappointed. That's a given.
I run mine with a Mesa 50/50 on HI-POWER, with the volume and presence dimed. I adjust the preamp's volume to taste. I've gotten more useable sounds out of this amp than any amp I've ever owned.
For tube amps I've owned a Marshall Valvestate, Marshall JCM2000, Marshall JCM900, Mesa DC-3, Mesa Dual Rectifier, Carvin X-100B, and a Fender Bandmaster. Up until this point the only amp that I was almost completely satisfied with was the Mesa Dual Recto. I was still looking for that certain something however and I figured if I could have a Mesa/Marshall rig, I'd be in tonal heaven. Turns out I was right.
If this piece of equipment was half as bad as some of you say it is, would we have modern legends like Stephen Carpenter, Billy Corgan, or Tom Morello using it in their every day live and recording rigs? Hell, "Around the Fur" and "Mellon Collie and the Infinite Sadness" were all done with the Marshall JMP-1. You tell me that those tones aren't something special.
I've seen people do anything from mild blues rock to SLIPKNOT, that's right I said Slipknot and pull it off with ease. Just to humor myself I went home to see if I could get a raunchy, blistering nu-metal tone out of it. I rocked my own fucking socks out of my shoes. It's got that bass that makes things shake, those mids that are dark and cut right through, and the treble that sits right between your ears. It sounded like a fucking DIEZEL or an ENGL. I kid you not.
Once a person knows how to effectively tweak the EQ and use each Overdrive channel respectively, this amp is an invalueable asset to one's rig, live or studio. Our band recently cut an EP this summer and I did all of the guitars for the EP. You can check it out at www.myspace.com/descentedsilence.
I've talked to people in person who have owned this unit and are ultimately disappointed with it. My first question is "what kind of power amp are you using", 9 times out of 10 they will say "a solid state" something or other (Peavey, Yamaha, Nady). Well there's your problem. The GUTS and BALLS come from the power amp, and the gravy on top comes from the JMP-1.
Not nearly as rugged as the Mesa/Boogie stuff I've owned in the past, but it's very close. Cosmetically, it's weak. The knobs are fragile and I've lost one of the hexes off the headphone jack already. Otherwise it's a solid unit. Never had a problem with it performing.
There is some hiss and noise problems, especially on OD2 (feedback galore with a humbucker guitar). That's one gripe I have but I'm sure it's an easy fix with a noise gate.
I play anything Alternative Hard Rock and I dive into a bit of Metal territory at times. It has never failed me.
So far I've NAILED (spot on with the record) tones from the following bands :
Paw, Smashing Pumpkins, Pantera, Metallica, A Perfect Circle, Silverchair, Stone Temple Pilots, Everclear, ZZ Top, Hammerbox, Dinosaur Jr, Nirvana, AC/DC, and Van Halen. I'm sure there's more in there that I just haven't discovered yet.
Marshall describes this unit as every JCM and JMP head in one compact unit. They're not lying - it's in there, you just have to know what you're doing.
The presets are nothing special so don't waste your time judging based on the presets.
Hopefully soon I'll get some Pumpkins' clips up on the web. It's immaculate, almost scary how close the tones are on "Where Boys Fear to Tread", "Zero", "Porcelina", and "Jellybelly" are. After all, the album was recorded with a JMP-1.
Don't listen to the naysayers, this is a great preamp.