Category Archives: Design

Neutrik powerCON Connector

I haven’t had much tome to work on the amp but I am getting back to it! Instead of using a I.E.C. power cable that can be stepped on and yanked out, I am employing a Neutrik powerCON series connector. This is a locking connector that can take heavy gauge cable. I used a step bit to drill out the hole to accept the fatter body of the Neutrik.


Perf Board Redo Do Over

I thought about the perf board over in over during nights of insomnia which is pretty much every night for me. I have a restless brain. I decided to return to the 8 hole high board to be more consistent with existing circuit boards of this era. Looks are important! I redid my layout for the third time. This is crazy I thought. “Can’t I just build this thing?” To me a lot of the fun is in the details. I like things just so and that sometimes requires revisiting the design. Here the latest 8 hole high layout: Screen Shot 2013-07-22 at 2.41.55 PM

Faceplate Design

Since this is going to be my JCM800 of a lifetime, I decided I am going to do custom brushed gold metal front and back plates. I am just getting my feet wet using Adobe Illustrator and it is a tricky change from my normal CAD program. Here is what I have so far. Big thanks to my drummer and best friend Tylor Durand for Illustrator advice, and Art Thompson for font consultation. The faceplate is combination of a JMP50 4 input and a JMP50 Master Volume. I am still playing with the logo and may go for a more JTM black flag look. faceplate

Perf Board Do Over

With the new design change I needed to cut and drill a new circuit board. Instead of using a plain paper template which caused misaligned holes on my last attempt, I used adhesive paper and split the design of the board into two halves. I couldn’t see paying for expensive legal adhesive paper and waiting for it to arrive in the mail. I always cut the template with a ruler an an X-ACTO knife. Scissors do not cut straight enough. I strive for precision even if the gain is small.

I stuck the two halves onto the Paxolin material. I added little pointers to the drawing to help line it up. I drilled the 288 holes very slowly this time. I also increased the speed of my drill press from 1600 to 2400 RPM as the drill bit tore the back of the Paxolin last time. The higher speed helped the drill bit to exit cleanly. The circuit board was already the right width, so all I had to do was trim the end off and sand it. I then peeled off the adhesive paper which came off very easily. I used a 3M sanding sponge to smooth the edges as they were sharp to the touch. There, now it’s perfect!

Perf Board Redesign

Already? I just started! I decided that I want to go with a perf board that uses 7 hole spacing between the component leads instead of 8. I measured this out and it looked too skinny. So instead of subtracting another hole I added another one and I will use these holes for cable strain relief. Of course I will have to re-drill a new circuit board, but I was not entirely happy with the one I just did. Here is the new design. jcm800_017