My amplifiers and preampliers modifications

Hafler DH-500 modified Upgrading posts, wiring and connectors Hafler DH-500
Counterpoint SA-7.1 Unfinished project Counterpoint SA-7.1
Audio Research SP-6B Minimum done on already perfect preamp Audio Research SP-6B
PS Audio Phono Stage II Various cartridge adjustments to get a testing tool PS Audio Phono Stage II 1976