I just acquired a vintage Stax SRD-X Adapter that appears to not be generating bias voltage. I am a tech and am looking to repair it before finding it a new home. Does anyone have a picture of the circuit or a schematic source before I dig in?
Stax SRD-X Repair Question
I did some preliminary troubleshooting and it appears that the amp section is fine but the bias oscillator is not working. It uses a 2SC1213 NPN transistor that I am having a hard time finding an equivalent. Does anyone know if a 2N4401 can be substituted or have another suggestion?