Rebuilding tube amps

I’ve been searching for a particular old school hack and ran across this little gem. I don’t know why I’m so intrigued by tube amps.. the high voltage, the glow, the power – oh yeah, never-mind. One of the most expensive parts of a tube amp is the transformer. They scored a pair of mono-block amps and walk us through replacing virtually every part except the transformers. My problem? I need at least 6.

simple signal generator

A decent signal generator is handy for tuning electronic projects. [SC] sent in this AVR signal generator. The parts count is really, really low. An ATMega8 is the core, and a shift register runs the LCD. Everything else is is built from simple components. The PCB is double sided, so it’s probably the biggest stumbling block. (But you can probably get away with making jumpers instead of etching both sides.)

[We’ll be heading out to Toorcon later this week, so send if tips early if you got em.]

Weekend workshop upgrade

I finally managed to pick up the 7×10 mini-lathe (on sale!) I mentioned in the diy dive light post. Seriously, there are more mods for this thing than a DS. There’s a great introduction to this handy tool over at I’ve been looking over the mods for a while to build up my buying furvor. Bill exploited the cycle of florescent lighting to make a simple tachometer. Dave streched his (Now there’s a kit for this from the little machine shop.) I’m thinking that I’ll whip up a pic/LED tachometer for my first mod.

Microwave oven arc welder

Today I’m jonsing for my mig welder that was lost during a move. Remember the microwave oven foundry? If you’ve got a few old ovens around, you can gut em and build an arc welder. The transformers generate the voltage, and an SCR circuit makes the arc adjustable. Of course if arc isn’t your style, you can build your own TIG welder. Since you can score an arc for $150-300, but a TIG costs more – I’d go TIG.

SMS VCR Remote

You guys love those erricson phones. Mark sent in this SMS VCR remote control. I guess it’s an alternative to a TiVo, or handy for those one man sting operations. I started poking around the site and discovered a few more interesting projects. The toilet telemetry was a bit odd. I want the duck taped kitchen timer for my espresso bar.