Quad 44 Erratic Input Switching

Thanks to Henk Vocks (NL) we can publish Quads paper on input-switching problems in some 44 preamplifiers.



The date of the Quad paper is 23/05/90 and the ref. is M12436-5.



QUAD 44 ERRATIC INPUT SWITCHING



A small number of 44 control units appear to be subject to pulses, triggering the electronic switching causing the unit to change from the input selected either to another input or to no input at all. The required input can then be regained by pressing the appropriate input selector button.



The cure is to:

1. Resolder both sides of the 10 feed through pins marked D, E, +, -, B, C, H, G, F and A on the mother board. Ideally the pins should be replaced with tinned copper wire. The pins are ringed in the attached diagrams.


2. Connect a capacitor min 4,7 µF across the +8,5V and -7,5V rails on the back of the mother board, as shown.

You can download this paper from the download-section of our website www.dadaelectronics.eu.

Stefaan.