That estate-sale tube amp has been sitting in someone's basement for forty years. Plug it straight into the wall and you might fry a $200 transformer, start a small electrical fire, or both. Run these six checks first.
The three failure signs that mean "don't plug this in." Spot them in 30 seconds.
The cooked-varnish, fishy, sweet smell that tells you a winding is shorted before you ever apply power.
White getter, rattling glass, loose pins. The visual cues that save a transformer from a shorted tube.
Why a 50-year-old amp never goes straight into a wall socket. The two cheap ways to bring it up safely.
What to watch for, what to smell for, and exactly when to kill power.
How to tell warm-but-fine from cook-the-insulation-hot, without a thermal camera.
The checklist tells you what to look for. The book tells you what to do about it: how to recap a vintage receiver, replace an output tube, trace a hum, and bring a dead radio back to life. Step by step, with schematics.
It's also the start of The DIY Vintage Audio Workshop series. Phono preamps, vinyl care, and tube amps are next.