Audio Vois Amplifier Repairs
Audio Vois Pre Amplifier
This one needed the volume pot replacing, used a 'Noble' dual concentric one. The small capacitors had corroded wires and some of the corrosion had leaked onto resistors which needed replacing. One of the regulators also had broken leads, LM317's replaced and secured the heat sinks to the board to stop them swinging around.
Audio Vois Pre\Power Amplifier
This one needed repair, the case is too small to dissipate the heat from the heat sink and I reckon not many lasted for any length of time, (from the early 80's). The company was formed by ex Naim employees and listening to the power amp shows it sounded quite good, not sure of the power output but the supply rails are +\- 35 V. The problem was the Vbe multiplier transistor had gone s\c, this senses the temp rise from the o\p transistors and keeps the quiescent current reasonably constant or it should in this amp. The transistor is mounted on the PCB in front of the light coloured pre-set in the middle of the board. There is no o\p protection in this amp so speakers beware, except for supply fuses.