Category Archives: QUAD II

Quad II

Quad II circuit diagram

Transformers and output transformers

Capacitors Original

Capacitor New

Pics

Pics 1

Pics 2

Pics 3

Modded Quad

Valve design

Vintage design

Output power of the QUAD II amplifier can be increased >20W by fitting larger power supply capacitors with increased peak power for better bass transients ~ Hum and residual noise improve to >100dB ~ The polypropylene bypass to both sections and the capacitor mounting method tend to give an improved sound reproduction from what is already a very good valve amplifier