1974 Marshall (18W) or JTM45...Which One?

Discussion in 'Shock Brother's DIY Amps' started by taylor714bce, Jan 23, 2016.

  1. Daz

    Daz TDPRI Member

    Sep 21, 2004
    Vancouver, BC
    This is going back about 9 or 10 years, but I've built a couple JTM45 variants and a couple 18 watt variants. Second amp I ever built was an 18 watt 1x12 combo faithful to the original circuit. Next amp after that was an 18 watt head with treble-middle-bass control. I hung on to this one for a bit and had it alongside at least one of the JTM45s. I had ample opportunity to swap both through the same 2x12 cabinet that I also built.

    Both were wonderful amps capable of warm, bright cleans, sweet overdrive and killer rock crunch. In terms of volume, the 18 watt TMB and the JTM45 were pretty comparable, which was surprising 'cause my original 18-watt 1x12 combo wasn't terribly loud (but very very sweet and the most mesmerizing tremolo I've ever heard).

    The tone *was* a bit different. The 18 watt had a nice thick and creamy midrange quality - like a vox-esque Plexi - and the JTM45 was warmer sounding, a little less gainy with more more bottom, less mids, and more highs. Slightly more Fender-y cleans.

    I miss both amps dearly!
  2. Guitarteach

    Guitarteach Poster Extraordinaire

    Aug 6, 2014
    Check out the modded 18w design at Ampmaker. I know he ships his kits worldwide.


    Hot (cascaded gain) and Normal inputs - great clean to light dirt and overdrive (that you can make foot-switchable)

    Switchable bass cut to tighten up bassy pickups and semis

    Push Pull / Single ended output modes - fat, loud and warm to bright and complex - awesome mod

    VVR on power section is really great

    It's a very bright amp but strong in the mids too and I've heard even the Marshall engineers said it was the best circuit the company ever made.
  3. Jimclarke100

    Jimclarke100 Tele-Afflicted

    Sep 8, 2009
    Horsham, UK
    I'd go with Iggyt and seriously look at the PA26.

    My last build was a PA26 using a pair of EL84s following a recommendation here. Plenty loud for my needs, and sounds fantastic - to the point I'm seriously considering trashing my Princeton build and reworking it to the same circuit but using 6L6. The only concern I have is trying to work the reverb in there as well which may affect the tone...

    My PA26 is I head form, rather smaller than the standard Marshall head cab, and so could be played through a 4x12 if that's what floats your boat. I generally use a closed back 1x12.
  4. rocksmoot

    rocksmoot Tele-Meister

    May 6, 2012
    Rogers, Arkansas
    I have an 18 watt combo in a 2x10 configuration (two Weber blue pups iirc) with a normal and tremolo channel. It has a beautiful sound going, and make no mistake, it is loud. I keep it at about 4 in band practice which gives nice cleans with some hair on tap with pick attack. Very versatile amp. I use the tremolo a lot more than I thought I would, particularly nice at low speed and half depth.
  5. Dennis Perusse

    Dennis Perusse Tele-Meister

    May 12, 2011
    Amesbury Mass

    I'd also go with the 18 watt but do it with a twist. Have an 18 watt with a 4x8 cab combo unit. You wouldn't then have to haul a 4x12 second cab around if you were doing a head cab plus it will look smaller than a fender bassman 4x10 setup and fit in your car much easier as well. Best of luck on your choice to build. :)
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