2 Channels vs Bassman/JTM sounds


New Member
Sep 20, 2020
Hi All and Happy New Year!

It's been a while since I've posted. I have acquired a couple of PRS amps over the past couple of years that I really have come to spend most of my time playing; a 2 Channel H head and a 2 Channel C 1x12 combo. Both are excellent amps, and I really enjoy the 'H'.

I've recently been going through my gear, still hunting for a couple of sounds that I haven't been able to track down and add to my collection (yet). One thing I've been looking for is more reminiscent than anything. A good 20 years or so ago I played through a Bluesbreaker combo, and it was one of the best sounds I'd made, and haven't been able to forget it.

I started to think about adding a JTM45 or even a Bassman to my collection (I've since learned they're nearly the same circuit or maybe the exact same). Does anyone with JTM/Bassman experience know if that's a vastly distinct sound from what I can get out of the 'H'? I'm going off memory and poking around online to see if there are references to this being similar to either of those amps. I had a buddy that swore this pulled off his blackface bassman sound but better. Probably need to fire up some old Clapton albums and refresh my memory!

Other amp I've been looking for is something with the early 60's brownface harmonic tremolo circuit. Considering just getting a new build to fill that void, as all the vintage amps I come across are asking around $4k give or take, and that's a little more than I'd like to invest.

Appreciate any thoughts on the above.

I Always Say Buy All The Amps. :)
Have you played a Goldfinger 45? Looked at some listings and seems like a great amp; would also look nice on top of my Bogner cab!

I’ve got a ‘68 SF Pro Reverb that I may sell or trade this year. I just sold a Super Sonic that was a fun amp, and a JVM 100 watt monster that was great, but wasn’t a huge fan of the reverb.
If you search the interwebs for schematics, you'll find the Fender 5F6A Bassman and initial Marshall JTM45 circuits to be identical. Where the Marshall amps change is generally in the increased power supply values and bias circuit accommodations for the European-available KT66 tubes which make for a stiffer sound. I've built both circuits. I built a stock Fender 5F6A into a tweed 410 combo cab running Jensen alnicos, and then built a JTM45 biased for KT66 and it is without doubt unlike any other amp I've played through. That JTM45 circuit is British grandfather rock-and-roll gain, 4-input magic. The channels ought to be jumped for maximum effect in both amps. When played through either greenback or mixed ferrite/alnico speaker pairs with an ash-body telecaster, the JTM45 is guaranteed wood. The Bassman is like playing through a diamond saw, crystal clear when rolled back, and on fire when cranked, old school style. There is nothing like a cranked Bassman/JTM45 tube amp. GO FORTH.
Aren't the PRS HDRX amps loosely based on the JTM45s? I wonder how the PRS amp circuit compares to the Fender 5F6A Bassman's.
Aren't the PRS HDRX amps loosely based on the JTM45s? I wonder how the PRS amp circuit compares to the Fender 5F6A Bassman's.
That’s cool, I hadn’t heard that. I’ll do some internet reading over the weekend, see what I can dig up on it.
That’s cool, I hadn’t heard that. I’ll do some internet reading over the weekend, see what I can dig up on it.
The HXDA was cloned (as closely as can be done given parts availability) from the actual Duane Allman Live at the Fillmore amp - it was provided by the Allman Brothers, who were PRS amp endorsers at the time and knew who had it. It's a Superbass circuit.

PRS was also loaned one of Eric Johnson's Superlead Plexis, and they discovered that the difference between the two circuits was only a few parts, so they incorporated three switches that gradually take the amp from one to the other - the parts for both circuits are present.

With the switches in the DA position, as soon as I played the first few notes through mine the hairs on the back of my neck stood up. There it was - THAT sound! The HX position is a real deal Superlead sound from the late '60s era amps.

It's been a constant companion in my studio for nearly ten years, is built like a tank (hand wired, thicker-than-military-spec tag boards, etc, thicker than what they were using on the 2-channel amps with more hand wiring), sounds the business and is a serious professional amp in every way. I also really like the two channel amps that you have, but the HXDA is in a different league.

Nothing hits the mark on those "in between dirty and clean, edge of breakup" tones like a single channel amp.

Try one, or check out the PRS demos. It's a pretty cool amp. The Mike Ault demo shows off the clean tones as well as the dirty tones.

Part One of the demo:

The reissue Marshalls are good, but there's really a step up with the HXDA.
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