Model: IC -275 Bulletin: B1003 Subject: Improve voice synthesizer and side tone audio 1. Remove C214 (.47 uf capacitor) from the main board. 2. Install a .1 mf 16V barrier layer capacitor in series with a 2.2 K 1/8W resistor from the emitter of Q58 and the base of Q59 on the foil side of the board.