Cambridge Audio A640 repair
My Cambridge Audio A640 integrated amplifier has been suffering from
drop-outs and clicks for years. I discovered that it got better after
switching sources a couple of times, which forces the output relays to open
and close. This led me to believe that there could be a bad contact in the
I ordered a couple of new relays, put them in and the problem is fixed!
Crystal clear sound again!
Overview of the main board and -encircled- the output
Detailed view of the output board and indication of
the connections of the two relays. There is one relay for each channel.
I didn't take the trouble of getting the board out, as that required
disconnecting and unmounting too many other things. Just take off the
speaker connectors to loosen the board somewhat and replace the relays
from below the output board.
The new relays: Omron G2RL-2, 12V coil,
8A switching current, 250V/AC switching voltage