I've been a bit sneaky ...
I did buy the Marshall JMP-1H a couple of months ago, but I didn't want to post my opinion on it straight away ... sometimes it's easy to get over excited when a new amp arrives at the front door.
Well, 2 months further down the line ... and I'm still in the honeymoon period, I think it's an excellent amp, it's been in use everyday since I got it. It's a punchy little number, I tend to run with the bass set fairly high, and the treble set fairly low. It's also got a boost switch that brings in an additional gain stage. So it can do 60s well, 70s/80s very well.
I matched the head with an old Marshall 1922 cab. For speakers I put in a couple of the Celestion Heritage greenbacks, a G12M and a G12H (55Hz). My thinking was that the 55Hz bass cone of the G12H would compliment the G12M ... sounds good to me
The reason I opted for the JMP-1H was for simplicity. I wanted to re-visit the 70s ... just dial in the amp, and roll with the volume/tone pots of the guitar for controlling the desired gain/tone.
Looking to the future ... If I get bored I've got the option of doing some tube-rolling experiments, 2 x ECC83 preamp tubes, 2 x ECC81 power tubes.
Just a thought ... if it had an effects loop I could run an MP-1 through it as well