Going off Grid - Taking a schematic and adding to it

Anyway, due to my inability to realise where a fuse goes, I found myuself with a power transformer (100w) for a mrshall-esqiue style build. I also have had a jtm45 chassis lying around I'd meant to do a boring jtm45 in as a "intrroduction to turret builds" project. However, the jtm45 is a grandpa amp, for people who like blues, strats and ignore massive racism whilst extolling how great Eric Clapton is...
So, it's about time I took something I want to build and add some stuff to it. Going a bit off the beaten path, going off grid, and just using that as a way to learn a bit more.

One thing led to another, and after finding out that I could remove one of the bellhousing side from the transformer, and that that it by some freak coincidence just perfectly fit in the transformer cut out of the JTM45 chassis.

OK, but at this stage, I still didn't know if the transformer was still good. I mean, I thought it was, but you never know. So I bolted transformer in, did a rudimentary connection to the mains, and then measured the HT windings and some others. Success! Not dead! And thus, a project was born!

I'd been toying with the idea of making a clone of the Fortin Meshuggah amp (yet another modded Marshall(tm) if you look at the schematic) so I kind of decided that I'd go down that path, and just use things I had, like the power transformer, and the chassis which fit together so nicely.

So, that was phase 1. I was going to build a clone of it. Awesome.

And I was going to do my own turret board as, well, why not...

But then, then things started happening...

I had this thought, which kind of came from really liking the forin 33 boost clone I'd built last year. I had a spare board. I could, you know, add that in. And I could make it switchable, via a front panel toggle. That would be cool I figured. 

Then I started thinking, i mean, what if I made it footswitchable? Wouldn't that be cool? 

This kind of opened the gates to feature creep somewhat. If you've ever worked in software, you'll know "feature creep" is where you get asked to build the program equivalent of a shoe. And then little things keep getting added, and before you know it, you're now making a shoe with jet engines, wheels, little wings, a satellite dish, miniature kettle and an anchor instead of brakes. So yeah, more things got added to the list.

So, boost board, cool, we can do that. But maybe I'd like to footswitch the 2 "channels" instead of swapping the input jacks to get the effect. OK, I reckon I can do that. Looks like it'll be a doubnle relay as channel 2 has a capacitor to ground. OK, I can do that...

So now we're up to 3 relays.

Then, then the next idea happened about 47 seconds after watching a lee jackson marshall mod video.

My brain tickled, and I asked "the" question. What if I wanted even more gain (because the meshuggah amp definitely does not have way more than enough gain already. And the boost won't have added any gain either at all... *cough cough*). That'd be a great idea. I can also make that switchable.

So there it happened. 4 relays.

And to make sure I didn't chicken out, 15 minutes later I'd drilled out a new tube socket hole in the chassis (first time for everything, it's a little off, but I can live with it, like 1-2mm closer to one tube than the other)

 No matter though, it's all about the intent. 

And to make the intent more intentfull, i went of and wired all the heaters to the sockets. And thus, mistake 1. I forgot the power tube sockets are bolted in 45 degrees off to what I am used to. Cue me wiring the heaters to pins 1+6 instead of 2+7. Stupid. Easy fix having spotted it now, but still stupid. Stupid as in if I hadn't of seen it now, it may well have caused some kind of fun tube or amp death and maybe magic smoke at some point. However, I'll never know as I caught it before it was too late. Phew!
 

 

 

Next bit, seeing as I was there, was fitting the cap cans. Here it turned out that the chassis was drilled thinking you'd be using a small little 45 or 50w power transformer, not a retarded big 100W one. Plus, the clamps I had, wouldn't fit, so I needed to redrill new holes. Eventually after enough procrastination, drilled them, just about fit, and m,ounted the cap cans. unfortunately, the clamps aren't dead centre around the hole, so the terminals on the cap cans look a little close to the chassis. I'll revisit when i wire them, and then maybe heatshrink, electrical tape, or most likely as it's the most fun, a hot glue gun, because, hot glue guns are awesome!

So there we have it. I've got ferrite beads on order, magical mustard caps, some sick as hell R


ussian radiation pilot lights, a 50w slo output transformer, 5H choke, and many other bits (actually, this is a lie, I have them already, but i wanted to build up suspense for next post)

I'm going to taking my time with this one, seeing as I'm doing a few things for the first time here, and this one might take a bit longer, but that's ok, as I'll hopefully learn a ton as I go along.