Reducing Digital Noise in Audio on Club Deluxe Board

Applies to Deluxe boards sold before March 13, 1997 (sold with main
board serial number 1211).  If port 2 is noiser than port 1 and the
noise tracks the TX pot but not the RX pot or tone pot, try putting a
cap between pins 4 and 8 (ground and +12) on U11 (the 8-pin op amp,
often a MC34072P).  This may reduce the noise on the 12V power supply.
A 0.1uf cap will probably work just as well as a larger one.