The F606 is a high performance professional two channel unbalanced to balanced converter with variable gain. It also provides polarity reversal for each side and a clip indicator. The F606 is intended for Bento racks which provide two inputs per slot, so stereo modules are possible.
This is a utility module perhaps most used to connect consumer gear to the professional studio, such as connecting a client's portable device in the control room. It can also be used to connect hi-fi gear, synths, guitar amp modellers, etc. Typically a low noise, high impedance input is needed. Consumer gear may be 10-20 dB lower level which requires gain, however fixed gain is rarely optimal. With 26 dB of available gain, with a high quality volume control and phase switches make easy work of otherwise compromised set-ups.