Phase-Linear Amplifier Repairs

Phase Linear PL400

Phase Linear PL400

DC fuses blown, replaced all o\p transistors, powered up one channel 'cracking' at higher than low volume. Changed driver transistors (T03) sorted, set bias to 360 mV across 10 ohm resistors, sounded fine, owner took it away, however, with his speakers there was distortion. Mid to high frequencies, checked nff with my speakers.