“The Compact Tube Hybrid Amplifier” designed by Alex Cavalli and ‘cfcubed’ is almost legendary. Currently at version 1.3b, CTH has matured into a sonic powerhouse – a tube rollers dream. CTH has the following features:
- Compact Tube Hybrid fitting on a 75mm X 120mm board (able to fit: Hammond 78mm X 120mm X 43mm case).
- No trimpots in front end. Rolling 12AU7 class tubes consists of turning off amp, pulling one tube & inserting another. Can be 6922 class tubes too (switch for 6.3V / 12.6V heated tubes). Many other tube types have also been found to work well (6F8G, 6CG7 6GU7).
- Runs tubes at 80V, about twice plate voltage of some other hybrids.
- Uses discrete output buffers, rail splitter, driving most all conventional/dynamic headphones with ease.
- Implements variation of AMB’s e12 muting delay & offset protection (with red and green LEDs).
Our CTH boards have a red mask to distinguish them as supplied by Joe Audio. We’ll soon be providing a variety of kits and options, making this amp/build one of the best investments you’ll ever make.