This preamp produces an awesome variety of sound permutations- as one component in the rig. A very important aspect of what our ears hear is due to the speaker configuration. Most of the reviews I read here just address the electronics and completely ignore the importance of final tranducers- the cabinet(s). If one has a dark cabinet, then the rig may lack clarity and punch. The unique sound one searches for requires the 'right' speakers, maybe a tweeter and/or different brand/model speakers in the cabinet- each with separate frequency contributions to the final tone. Home stereo speakers generally have a least two different drivers in each cabinet (and a crossover) to deliver the frequency span. Hey get with it people, configure the final interface to the ears to correctly deliver your sound. Sophisticated electronics without sophisticated cabs produce something less than optimum. Traditionally, guitar cabinets employ an array of same-type speakers in a box with no crossover controls. This is a neanderthal approach to getting the desired tonality- hit or miss. Yeah, spend the cash for quality electronics- but be aware, cabinet design/tuning, speaker selection, and crossover circuitry will contribute mightily to the sound you project. I'm using the JMP-1, Lexicon MPX-500, BGW Pro 100 (solid state)stereo power amp in a 3 space MTS rack, about 40 pounds weight. Not much bigger than a head, but way more versatile. Driving a single modified Ampeg SVT-210HE cabinet with Eminence Legend 105's, stock tweeter/modded crossover with L-pad, sealed the 2 rear bass ports. I can dial in cabinet clarity with the L-pad for whatever volume I'm driving. Guitars are an '88 Les Paul custom with EMG 85, 89, and a stock '69 SG. Sound is tight, bright or brown if wanted, with great chunk and presence.
No problems, a solid quality build. Watch out for that memory battery though, it will leave you dead-in-the-water when it runs down. Just replace it once a year as preventive maintenance. A nine rating because this is easy to overlook.
Great addition to my gear. This rig (all of the individual elements are part of the package) cranks quality sound. Been picking 30+ years and have played many venues- mostly rock and metal. This is the most compact ass-kicking setup I've used- and have owned/tried a lot of gear over the years. If the JMP-1 were stolen or lost, I would replace it straight-away. The important thing to be aware of is; every detail of your rig- guitar, pickups, strings, electronics, cabs contribute to the final sound- it is a complex component mixture that delivers the 'sound' each is looking for, and it is different for everyone.