For a good while now, I've been after a Marshally amp with a little bit more gain on tap. My JTM45 is a wonderful thing, and it can get into heavyish territory, but it's not an amp that really enjoys being pushed right to the edge. The JMP/JCM Marshall circuits are much more refined in that sense - being designed FOR heavier gain.

I spotted an amp on eBay that really piqued my interest - a Morris Perplex'd Jr 30 - and I picked it up from a fella in Chessington at the start of this summer. On paper, it was an interesting concept - 30W, tube-rectified, cathode-biased, Class A, and no negative feedback. So it was a bit of an amalgamation of Vox and Marshall. For me though, it was a little lacking in trademark Marshall upper-midrange sizzle; and was also very very thick...it was tricky to dial out the bottom end to a point where it was useable with most guitars and speakers.

I was chatting with Glen Morris, and he told me that the transformer in this amp would allow it - with some modifications - to run at 45W, Class A/B, and fixed bias...much more like a classic Marshall Plexi. That sounded much more up my street...so, he sent over details of what the changes would need to be, and I gave it to my local amp tech here in Bristol (Mike Devine of Amploft) who performed the operation. So it's now - basically - a 50W Plexi, but tube rectified....cool, eh?

The great thing about this amp is that is has two very distinct personalities accessed through the Gain switch. In Mode 1, it's a very warm, vintagey 70's JMP type affair; but in Mode 2, the gain shoots up, the low end is tightened and it becomes much more sizzly...getting into aggressive Appetite For Destruction-type territory. So with that one switch, you can turn a warm, vintage Plexi into a modded, angry Plexi!

Today, I'll be putting a variety of different guitars through it and cranking out the dad rock riffs. But I'm also going to use two cabinets - one with my standard AlNiCo speakers, but another with some Greenbacks to really bring the 'DC!

What do you think? A classic rock monster? Or not for you? Comment below!

Guitars:
- Gronlund w/ TV Jones Ful-Fidelity Ray Butts Filter'Tron
- Fender Esquire w/ McNelly A5 Standard+
- Gibson Les Paul Standard w/ ThroBak SLE-101 PAFs
- Gibson SG Standard w/ OX4 A4 PAFs
- Gibson Les Paul Junior w/ Monty's '54 P90
- Gibson Les Paul Custom w/ McNelly Stagger Swagger V2s
- Heritage H-535 w/ ThroBak PG-102 NOS PAFs
- Ron Kirn Barnbuster w/ Don Mare Hot Bakelites
- Bailey Curve Special w/ Northern Pickups A3 T-Tops
- Fender "FiftyLuxe" Tele w/ Monty's Wide Range Humbuckers
- Fender Partscaster Strat w/ Mark Foley 60's Pre-CBS

Amp is running into a Zilla Studio Pro 2x12 cabinet loaded with Celestion Gold & Fane A30 AlNiCo speakers; and a Villa Fatboy loaded with Celestion Heritage G12M Greenback & Warehouse Invader 50 ceramic speakers. Both cabs recorded with '70s Sennheiser MD441, Shure SM57 and sE RNR1 ribbon mics, with a Schoeps CMC6 room mic.

0:00 Intro
7:02 Playing
14:48 Outro

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