Hallöle,
also beim Musical Fidelity A1 gabs da ein Problem im Vorverstärker; der A2 ist wohl ein update, weiß nicht wieviel elektronik die sich teilen - möglicherweise gar keine :-). Vielleicht hilft es ja trotzdem weiter um an die Lösung zu kommen.
grüße
Thorsten
http://www.mhennessy.f9.co.uk/mf_a1/
Auszug :
What goes wrong?
Noisy pots and switches:
The bane of my life! It's so embarrassing to have a half-decent hi-fi that you can't adjust the volume! The failure mode is deposits on the track, particularly at the lower end of the scale. Due to the stupid design of the preamp, the problem is compounded: as the wiper hits dirt and goes high-resistance, the volume is effectively max'd for a brief time. If the configuration was conventional, the sound would do the opposite, making the effect much less objectionable...
Also, the switches are affected for the same reason - the input op-amp stage puts dc currents through the switches...
As noted above, replacing the pot and switches is a short-term solution. If you retain the original preamp, the new components will go the same way. I guess it's possible that MF found different components that were more reliable later in the amplifiers life...
