Thank you for putting that all together, and sharing it with the world!
I used to have your old website bookmarked, and visit it often. At the time, it was one of the very few valve guitar amp resources I could find that wasn't full of superstitious malarkey about mermaid-oil capacitors and vintage catgut transformer insulation.
I was saddened when the old website disappeared, and a little concerned about the welfare of it's creator. Glad to know you're alive and kicking, and have a new website to boot.
-Gnobuddy
Thanks for the compliments. It's always nice to hear that someone appreciates my website. I thought of a better name for my website (ephaseaudio), and moved to Godaddy after someone highly recommended them.
Right now I'm working on a bluetooth or AUX in "boombox" for camping or picnics. It uses class D poweramps and Lithium batteries, each of which are new technologies for me. I'll do a page on it for my website eventually. It will have two TC9 Peerless 3 inch drivers on the front, and two Peerless 3.5 inch passive radiators on the ends. The poweramps will crank about 20watts per driver with about 20VDC from 6 lithium batteries. My bluetooth smartphone will act as a wireless remote control, and will hold all the music (about 9G worth at present).
I actually have a somewhat similar project rolling around in my head. I want to put together a small portable P.A. system for an outdoor acoustic guitar jam at one of the parks around here, before winter arrives. The P.A. is for vocals, and may also have a 1/4" jck for one electro-acoustic guitar to plug in. There is no electric power at the local parks, so it has to be battery-powered. You probably already know this, but there are lithium batteries, and then there are lithium batteries. The "lipo" batteries used in cellphones (soft plastic pouch enclosure) can be extremely dangerous and have to be treated with a strict regimen of safety protocols; I personally know three radio control hobbyists whose suffered serious vehicle fires because they failed to follow the rules. Two of those vehicles were completely burned out and totalled, and the third one should have been, but the owner had no insurance, so he scraped out the burned plastic and foam and carpet, re-wired some of the harness, and kept driving it. Google for "lipo fire", and you will find plenty of heartrending stories and pictures of destroyed cars, destroyed garages, even destroyed homes. When things go wrong, lipo batteries are not a forgiving technology. At the time I was also involved with (electric) radio control model aircraft. I used lipo packs too, with a lot of precautions; they were transported and stored in a fire-proof safe, only charged outdoors (with a ziplock bag full of sand on top and bricks all around), regularly inspected for puffing, only charged with a balancing charger (maintains cell-to-cell balance), et cetera. I did have cells that puffed, but detected and disposed of them before they caught fire and destroyed my home, my car, or my RC models. Somewhere post-lipo, MIT researchers invented the LiFePO4 battery, and spun off a factory to make them (A123 Systems, I think). Those were (are) the safest lithium batteries you can get, but A123 has been through bankruptcy and resale, and I don't know if you can get your hands on their cells these days. They also need a charger which understands LiFePO4 chemistry - the charging protocol is different than lipo and lithium-ion. The first pro-quality lithium-powered cordless tools in North America were 32-volt Dewalts using a ten-cell A123 (LiFePO4) battery pack. When A123 systems went under, Dewalt and all the other tool manufacturers switched over to lithium-ion cells; very similar internal chemistry to lipo, but with a hard metallic casing, and rolled internal electrodes. They are not as volatile as lipo, but not as safe as A123. I would not use a lipo pack in a DIY boombox for anything. They have a nasty history of puffing up due to manufacturing imperfections, and then catching fire on the next charge cycle. Not good for a sealed application that might be inside your house when it goes off like a Roman Candle. You are most likely going to find yourself working with these lithium ion cells, unless you are lucky enough to get your hands on some LiFePO4 cells of adequate capacity. -Gnobuddy
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