A15AS - Switchable Microphone Attenuator prevents preamp overload in applications where very strong signals are applied to a mic input. Provides 15, 20 or 25 dB attenuation.
A15BT - Bridging Transformer matches balanced or unbalanced devices of different impedances.(33 kilohm primary, 600 or 7,500M ohm secondary).
A15HP - High Pass Filter provides a low frequency cutoff to reduce unwanted low-frequency noise in mic signals.
A15LA - Line Adaptor provides 50 dB attenuation, allowing a balanced line-l