Basic Question regarding JTM 45 PTP board.

[Melodyman]

Hi all. New here. I was told by a Marshall forum guy that I might not hear much difference between the RI JTM 45 factory PCB and the Metro JTM 45 PTP board which I will be installing next week. I am assuming that the Metro PTP board contains some different components than the RI thus returning it to original 60's design and not a PTP copy of the RI PCB. Can anyone explain the differences?
Thanks.

[Mars Hall]

Hi all. New here. I was told by a Marshall forum guy that I might not hear much difference between the RI JTM 45 factory PCB and the Metro JTM 45 PTP board which I will be installing next week. I am assuming that the Metro PTP board contains some different components than the RI thus returning it to original 60's design and not a PTP copy of the RI PCB. Can anyone explain the differences?
Thanks.

The Metro PTP board is a vintage replica of an early model JTM45. With the upgrade you will be installing much better tone caps, especially if you opt for the Sozo upgrade. Not sure if George offers them , but Sozo also carries a "Vintage" cap, that is suppose to replicate the original "Mustard" caps, especially for the jtm45 amps.

With all that said, the upgrade will at first only reveal a slight tone improvement, because the caps need a "break in" period. Even at that, the tone change will not seem dramatic.

Another good upgrade to do at the time, would be replacing the filter caps with the more original values, where the RI's have 2 50/50 cans, the originals have a 16/16 and 32/32, which will give the amp a looser feel.

Dollar for dollar though, your biggest tone improvement would come by swapping out the OT for one of vintage quality. I've been through this twice, with a jtm45ri head and a BBri and I absolutely love the sound after the upgrades.