Thanks to George Metropoulis at Metroamp.com I'm working on tweaking my newest project which is a Marshall JTM45 Reissue gotten at Guitar Center on trade for my beloved JCM 800 50 watt combo split channel with reverb vintage 1986. In case you're not familiar, the JTM45 is Jim Marshall's first amplifier which was modeled after the Fender Bassman 5F6-A or better known as the '59 Tweed Bassman.

Why then, do you ask, would someone want a JTM45 instead of a Fender Tweed? For starters, the difference between the "Marshall sound" and the "Fender sound" is well documented and far reaching. Marshalls are known for their huge, roaring bottom end with wailing mids and glassy bright highs, think Hey Joe, Wind Cries Mary, Red House, Purple Haze,  Bluesbreakers Beano sound, while Fender's are known more for their clean tone, think Beach Boys, Dick Dale - Surf music, clean Blues and Jazz.

About this particular reissue, I believe by the serial number it was made the first week of 1999. George ay Metro made this killer clip of his JTM45 vintage clone version which sounds a lot more robust and full of sustain and harmonics than mine currently does, so I'm hoping with some small tweaks to gain more complex harmonics and sustain.

Until I can sell this one or start upgrading it piece by piece to full vintage spec, George suggested I replace the signal caps on the circuit board with Sozo caps (5) .022uf (4) .1uf (those are the little square gray blocks on the PCB board) and replace the Output Transformer which is hugely responsible for the character of the tone, sustain and roar associated with Marshalls. He had one meticulously made to vintage specs and which the top discerning critics rave about. I'm considering the swap since mine seems to lack just a tad in the sustain area but rocks in bottom end and highs. So first, I'll work on the caps and see what difference those make and then move on to the Output transformer. I also ordered a new set of tubes.

I will be posting some before and after clips here soon!

Meantime, here is a fantastic Premiere Guitar Magazine article about JTM4 clones vs. originals roundup which ranked George's Metro Amp up top of the list. Surprisingly, the PCB equipped Marshall JTM45 reissue came in second place. Though the one tested had EL34 output tubes instead of mine which has been upgraded from 5881/6L6 tubes to the beefier KT66 tubes as were the first used in mass production models by Jimi Hendrix, Clapton, etc when there was a shortage of 5881/6L6 tubes in England. However, the very first JTM45 amps made came with 5881/6L6s which are stock in reissues.
See 45 Degrees of Tone: The JTM45 Roundup

By the way, these are pure tone machines, I kid you not. The instant you hear one at stage volume, you just know this is THE sound that made all the great rock songs of days gone by from early Jimi to Clapton to Zeppelin. I brought this one below to an open mic last night for it's first test run. An old hippie dude complete with silver spray painted space boots plugged in his vintage Strat when I briefly walked away and starts ripping on a very loud "All Along The Watchtower" at this mid sized club. So I went to the back of the room and just listened. Man, if I would have closed my eyes I couldn't tell if it was Jimi or if it was Memorex. Then there's a guy with his expensive reissue Vox 2x12 Combo next to it which sounded like a piercing little buzzing toy next to the JTM45. Let me tell you, the amp is rated at 30 watts but with the KT66 power tubes into a 70 watt vintage 30 speaker, this amp rocks loud and strong and can blow the doors off small to mid-sized clubs.

In fact, to get the most out of it, I probably need a power attenuator to be able to dime it and wrench it's best tones at lower volumes because there were some walking in who said they could hear it all the way down the street and there were around 100+ folks in the room. I had the am set at around 7 but was using a Fulltone OCD overdrive with the volume barely on at around 8 AM to be able to keep the amp up loud but choke off some of the volume with the pedal. This is because the 45 doesn't start naturally sustaining till you hit around 8-10 on the main volume where you're up to around 55 deafening watts.