JMP50 Clone Build, Part 3
A year later, I’ve returned to my project JMP50 build. Transformers from Brian Wallace at Marstran, tube sockets and cap cans are all installed.
Over a year has passed since I worked on my JMP50 clone. Yikes… has it really been that long? Yes, well, life and other things got in the way. Back to building now.
I ordered the transformers and choke from Brian Wallace at Marstran last week and they arrived yesterday. Brian has a great reputation building first-class iron for Marshall style amps, and he’s a good guy to deal with—highly recommended. Good thing, too, because I ordered the wrong power transformer. I thought it was the right one, but his JMP50 power transformer (1202-164) is upright mount so I had to sent the original back in favor of a JTM50 unit (1202-118) which is laydown mount, hence the large gaping hole you see. It was a bit of a disappointment when I figured out that I screwed up, but I’ve waited a year so another week to get the right power transformer won’t kill me.
I decided to paint the transformer bells and choke frame black before mounting them, just to carry the black theme through the whole project. I cleaned, sanded and prepped the parts last night then sprayed them with black with a Rustoleum rattle-can.
Here’s the back. You can see the rectangular mounting hole for the IEC power cord socket at the right; this is one of the reasons I like Nik’s chassis. I alo like having the voltage selector. Good stuff.
And here’s the front. Nice shiny black transformer bell already a bit nicked up because I was too impatient to let the paint dry for more than a day before working on things.
Inside the chassis, you can see where I took a wire wheel to remove the powder coating near the socket mounting holes and grounding points to ensure a descent ground connection. You can also see how I oriented the cap cans and installed the ground lugs.