Bass amp build. Hilbish GT120

[madasahatter]

This will be a Hilbish Design GT120 amp build. It's pretty much a straight clone of a 70's Matamp GT120. Unlike the other couple amp build projects I did, this one isn't a kit. I had to source all the parts myself and there are no full instructions. Hilbish supplied only the schematic, wiring layout, BOM, voltage chart, and a handful of build pics.

I ordered a chassis and PCB back in December while Hilbish was having a sale. I got the chassis & PCB for a good 45% off. It took me a while to get all the components and small pieces, but I have most everything I need on hand now. I'm still waiting on the transformers, but they have been ordered.

I finally started today. I did a little bit this morning and got most of the the components on the PCB. I didn't put any of the lead wired (except one) or diodes on yet. I'll save that for later. I didn't realize how big some of those orange capacitors would be when I ordered them. I was concerned they'd be too big and get in the way of other components, but they ended up fitting just fine.

 

[coreyfyfe]

Good luck with the build. I did one a while back when he had boards but no chassis available. Ended up using a mojotone hiwatt chassis. It's a cool sounding amp. Loud as heck.

 

[Spedracer]

Bump, let us know if you've made progress. This is a cool topic.

 

[madasahatter]

Bump, let us know if you've made progress. This is a cool topic.

I haven't really progressed much from where I was at. I decided to use a different set of transformers than what I originally ordered. The Heyboer's I initially ordered didn't have the same leads and such as the schematic. They could work fine, but I would have had to do an artificial center tap and moved a few other wires around; things that would deviate from the schematic that I'm not comfortable doing yet. If I got it wrong I'd end up frying everything.

I ordered the Mercury transformers listed in the BoM. They took a couple of months to be built and shipped. Ordered in early January and I finally got them at the end of February. While I waited for those I started a couple of other projects. Built a bass from a guitar body I had sitting in the closet that's now become my main bass. I'm also currently doing a drop-in PCB mod to my Marshall Origin. Once the Origin is done; which shouldn't take much longer, I'll be back to doing the GT120 clone.