The Amp Garage

For a 50W version of this, which is more appropriate; the 290DX (Super Reverb - 325V, 50V bias supply, CT on the heaters & extra 5V secondary) or the 290EX (Bassman - 330V, 53V bias supply, & no CT on the heaters secondary)? Same question goes for the OT, the 1760K (Super Reverb - 4000 Ohms) or the ...

So it would appear that James posted the schematic up for the JTM/JCM1 in this thread, unfortunately the link is now dead :cry: http://ax84.com/bbs/dm.php?thread=460389 I don't suppose anyone was fortunate enough to grab a copy? I'm working on a turret layout for the JCM1 without diode clipping and ...

What level of gain are you looking for? The 2203/2204 amps don't have that much gain with the master volume turned down low. You could increase it by modifying the preamp but obviously it won't be a 70s Master Volume Pre Amp anymore. Or do you think you can cope with 20W? Its only 3dB quieter than ...

I think I might have to build something along these lines, my JTM45 build is just to clean at normal volumes and I don't want to start adding cathode bypass caps and changing the NFB resistor etc as that'll take the amp away from what it was built for and having another new amp is always better :D I...

What chassis are people using for these?
I want to build a 50W version and have just missed the boat as AN has stopped selling them

I'm in the UK but use mouser on a weekly basis, they have a decent selection of Hammond models.

Does anyone have a schematic of what we believe the JTM145 is, Matec's HTM1 with paralleled volume controls?

I was about to pull the plug on the 125a but I'll have a look at the one from RS. The JCM1 schematic would be helpful, I'm going to remove the Jubilee clipping and look at adding the #34 or #36 mod without the extra gain stage, test it out on the bench and then possibly have a dpdt switch between th...

Have you got scaling turned on or fit to page?

I've never used inkscape but know i have to tell illustrator not to scale things when printing.

Pity the ampmaker transformers aren't quite right for these, £10 for the OT is a bargain

I might just try the Hammond 125a, I think smokebreak used one of these, not sure on the impedance though.

I've put mine on the HT centre tap as per the metroamp instructions, if it's good enough for George it's good enough for me and my first build.

I'm surprised that we're still in the dark about this range of 1w Marshalls, they've been out for a few years now!

The Andertons JTM145 is my favourite, unfortunately the pictures of the tone PCB never surfaced

Be interesting to see the different designers way of reproducing the circuits.

Did you manage to fix the issues?
I've just finished my JTM45 build and want to build it a baby brother

The Andertons JTM145 is what I'm aiming for, like you i'm in the UK so would like to use the ampmaker transformers i believe you may have used.