He can be contacted at the NEW email address:
If you like to keep an eye on Douglas Self's website, click the box above. Be aware that the old site at aqpl43.dsl.pipex.com is no longer being updated. The Douglas Self Site is at: douglas-self.com
The Devinyliser is an innovative solution to the problem of subsonic disturbances from vinyl. Subsonic disturbances essentially cause vertical stylus movements, causing anti-phase signals in the Left and Right channels. L-R crossfeed at low frequencies cancels the anti-phase signals, converting bass information to mono.
The basic idea is not new but it has never caught on, because in all previous attempts the anti-phase filtering slope always comes out as -6dB/octave, no matter what order of lowpass filter is used to control crossfeeding. We have used sophisticated allpass filtering to time-correct the lowpass filter group delay, giving a much steeper slope of -18dB/octave from a 2nd-order Butterworth filter. The intrusion of crossfeed into the audio band is thus minimised.
Douglas Self presented papers on the Devinyliser at the 140th AES Convention at Paris in June 2016, and at the October 2016 meeting of the London AES at Kings College, London.
The Devinyliser PCB is available as PCB** £20:00 each
The Signal Transfer amplifier power supply provides a high-current power supply for feeding two of our power amplifiers, combined with closely regulated +/-17V supplies at 500 mA for powering op-amp circuitry, including the Low-Noise Balanced Input Card, and the Amplifier and Loudspeaker Protection Card.
Available as PCB0014 £27:50 each
The Compact Blameless Power Amplifier. A small-format Class-B power amplifier card that will fit into minimal space when the full low-impedance load driving capabilities of the Load-Invariant Amplifier are not required. in every other respect this design has all the features of the of the other amplifiers we offer, and it gives the full Blameless performance into 8 Ohm loads.
Available as PCB009: £23:00 each
A comprehensive amplifier & speaker protection card that provides relay muting and guards against DC offset errors that can destroy expensive speakers almost instantly. It also gives a slow turn-on and fast turn-off to mute power-up and power-down transients, two channels of over-temperature protection, and a shutdown input.
Available as PCB008: £23:00 each