Tube and Hybrid Amplifiers

Tube amps are all tube circuits. Hybrid has tube and solid state parts, usually tube preamp and solid state power amp. Many tube amp projects involve high voltage, know what you're doing before attempting them. There's an old joke about building amp that almost isn't a joke; "When building tube amps you should always be two persons, one who builds and one who calls 911". Think for a while what that means and consider considering it a guideline or even a rule instead of just a joke.

Tube

AX84 - The AX84 site has a few tube projects and a supporting forum.

Hybrid

Tube Cricket - Hybrid version of the Noisy Cricket chip amp.