A modern classic and designed by valve supremo, Tim DeParavicini, the II-eighty is much more than a homage to the Peter Walker classic - it's a complete re-interpretaion of the philosophy. Using 4 x KT-88s and a similar cathode coupled output, the lineage is clear to hear and see, but with such huge dynamic headroom, this amp is faster and with more control than any previous model.
The Latest addition to the Quad Valve Power amplifier series is the long-awaited Quad II-eighty amplifier. The perfect partner to our latest ESL speakers, the II-eighty is not merely a nod in the direction of retro styling, it’s a modern high-performance amplifier designed by one of the most famous tube-amplifier designers in the world (Tim De Paravicini) using more than a little inspiration from the original Quad II amplifier. The Quad ll-80 is an 80 watt mono power amplifier following in the tradition and philosophies of Peter Walker. The output section consists of 4 KT88 valves running as two pairs in push pull with the hallmark Quad topology of partial cathode loading in the output transformer. This method reduces distortion when compared to the usual Ultra Linear or triode methods, however, it does require a greater grid driving voltage. This is achieved, again in true Quad fashion, using a balanced pair input stage. The output transformer has been designed to improve high frequency performance and accurately balance the two push pull halves. Also the transformer has been designed to make sure that full output is realised at the bass frequencies down to 20 Hz. Each output valve has its own cathode resistors to provide reliability and self-matching. The screen grids of the KT88 valves are run from a lower voltage, again for good reliability. The whole amplifier has a total of only 16 dB of feed-back providing good stability into virtually any known loudspeaker and especially the famed Quad electrostatic loudspeakers.
Power Output:
80W RMS
THD @ 700Hz:
0.3% @ 40W
0.5% @ 80W
Residual hum & noise:
Better than -94dB
Frequency Response:
10Hz–30kHz(+0dB/-0.5dB)
Damping Factor:
16 @ 1kHz
Power Consumption:
180W maximum
Loudspeaker Taps:
4 ohm and 8 ohm
Valves:
2 x 6SH7 input
4 x KT88 Output
1 x 5U4G Rectifier
Sensitivity:
1V RMS