This could be the craziest thing I've tried yet and that's saying something. I am trying to figure out how to build a very stripped down Twin AB763 into a Princeton-sized chassis and cabinet, running a single 12" on top of it. I'm looking to get roasted, or advised or egged on (people love trainwrecks). Here's why I'm doing it: A friend who plays very loud and very clean asked me as a favor (he's paying for parts and drinks) to build a very clean, very loud amp in as tiny an enclosure as possible. He has a Fender Supersonic (I think) 60W, and he says it breaks up too early for him. Same with a Super Reverb AB763 he used to own ... he really, really loves the Twin AB763 (says it's his favorite all-time amp) and asked if it was possible to squeeze it all in to a compact package, with a single speaker. I told him it wouldn't sound like a Twin with just one speaker, but he just wants a single. He wants: One channel No tremolo Light speaker and cabinet Removing one channel and tremolo brings tube count down to eight. I can just BARELY fit all this stuff in on this 18.25" chassis. I don't want to put the choke and output transformers in the traditional spot because that will require either (A) a wider chassis or (B) a significantly taller cabinet for speaker clearance. So if I do it I will have to run the output transformer on the far end, and snake the leads outside of the chassis from one side to the other, so the chassis acts as a shield as the wires pass by the various amplification and reverb stages. The speaker could then be put up closer to the chassis, roughly in the middle. I had to rotate all transformers and chokes 90 degrees from traditional, because running the power transformer in the other orientation would not have left enough room to mount the adjacent 6L6 tubes behind it while leaving enough clearance on the other side of the transformer for the 3/4" baffle's depth. As for electrolytics, there will be no room on top of the chassis for a dog house so I thinking about running them along the top inside of the chassis, in a line from left to right, between the pots and the circuit board ... pretty much how Hoffman puts them in a lot of his projects. I started off with Rob Robinette's no tremolo layout, pairing it with Hoffman's schematic for a single channel, and came up with a layout taking those changes into account (see pic). Inside, there should be about two inches between the transformer and the left edge of the circuit board. That's where I will put the bias supply/pot. As for cabinet, I was thinking 3/4" yellow pine, with a 3/4" baltic birch baffle. I'd use T-nuts to secure the speaker to the baffle and the baffle to the cabinet. The speaker would be an Eminence Legend EM12N, a 200W neodymium that weighs about seven pounds and is supposedly fabulous in this type of application. Very efficient, neutral sounding and clean. I've been mulling this over in my head for a while now and am trying to think of all the pitfalls involved. I'm sure there are many things that I haven't considered or won't realize until I'm neck deep in it. What do you all think? Do your worst!!!