Wednesday, September 06, 2017

Misprint in Quad 99pre manual.

Misprint in Quad 99pre manual.

Several 99pre owners have complained of low volume and dull sound from the phono preamp. We traced this to an error in the user manual on page 10. It shows an example:

    moving-magnet input selected             PH 00

which should read

    moving-magnet input selected             PL 1.00 (or 3.00 or 7.75)

or else

    moving-coil input selected     PH 00

This is a mixup between 'high sensitivity' (MC) and 'low sensitivity'
(MM). Most people, us included, and perhaps the manual writer as well, think from the cartridge end, 'high output' (MM) and 'low output' (MC).
So 'high' and 'low' mean opposite things depending on whether you're talking about sensitivity or output level. The instructions given later on page 15 are correct.

So what these owners had done is set up their phono inputs as moving-coil, which has a very low input impedance, so most of the signal is lost, and the inductance of the cartridge plays an undue part in the LR filter formed by the cartridge and the input impedance. Setting it up for moving-magnet PL 3.00 solved the problem in every case.

Esmond Pitt

Dada Electronics Australia

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