The OTB16 is a 16 channel 1U mixer with 16 balanced inputs and a Tonelux discrete summing bus.
Each channel has a level control and a panner
The access to the OTB16 is through 2 eight channel Dsub inputs at a level of +4dBu nominal.
The summing of the 16 channels is through the famous Tonelux TX-240 and TX-260 discrete op-amps, and then throught the main output transformer, which can be adjusted by the MASTER fader pot, which comes out of a pair of XLR connectors.
Additionally there is a monitor output for monitoring or for expansion, which is balanced but transformerless.
2 additional balanced inputs to the MIX bus. The pre fader monitor output can be plugged into the BUS input to extend the number of channels with a second or third OTB16. 120 or 230 volts AC powered 50/60 Hz.