I thought I'd make a thread for the amp I'm working on at the moment. It's a little far into the process to do a full build diary, but then I've only recent joined this forum.
Last year I built a 50-watt amp for a bandmate based on the Marshall 1987 circuit, with added reverb. I like the sound of that amp but don't need that much power, so I've been working on a lower powered version using 6v6s. I got the idea of building a 6v6 version from Mark Huss' website, and that with a single 12" should cover any of the sort of gig I do.
I've used a set of 18-watter transformers from Valvepower, a JTM45 sized chassis from the same place, and a Hammond choke. I already had an old high-impedance reverb pan sitting around, so after doing some digging around online I decided to try adding a cap-coupled reverb circuit using a JJ ECC832 (12DW7) with the ECC82 side for the driver and the ECC83 side for recovery. I've used a single input going to both the normal and bright channels, and added a post phase-inverter master volume.
I've just got the chassis up and running this weekend, and it's sounding good. I'm still tweaking some things to get the tone and level of the reverb right, but otherwise I'm pleased that this one seems to have gone together without needing troubleshooting.
Next up I need to make a nice looking front panel overlay and build a combo cab for it. In theory I have access to a laser cutter for the front panel, but so far I haven't quite got around to figuring out exactly how to come up with a design in the right format for it. I should probably try and find that out...
I'm going to put it in a 1x12" combo cabinet for it, with red basketweave tolex to match the knobs. I've got a couple of different old speakers to try - a Fane Classic
12/70 from the early 90s and a Celestion G12/75 (not G12-75T) from 1978.
I haven't tried them in a proper cab yet, but the Fane seems brighter
and clearer and the Celestion perhaps a little dark (it's a 2" voice
coil, apparently). The Fane has a patched-up cone, so I have no idea if
it'll sound OK at volume or not. If neither of those is to my taste, I
might look around for a new speaker.