The Tonelux 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 D-sub 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 through 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 transformer-less. Two 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.

The Features
- The OTB16 is a 16 channel 1U mixer with 16 balanced inputs and the famous Tonelux discrete summing bus.
- Each channel has a level control, a panner with a center detent, a level indicator and each pair of channels has a LINK button to link the right level control to the left control.
- Access to the OTB16 is through 2 eight channel Balanced Dsub inputs at a level of +4dBu nominal, using the DA-88 type pinout.
- The summing of the 16 channels is through the famous Tonelux TX-240 and TX-260 discrete op-amps, and then through the Tonelux TX-100 output transformer.
- The Mixer output can be adjusted with the MSTR Fader, sending the signal out of the two XLR connectors marked "MIX OUT".
- Additionally there is a Monitor output for monitoring or for expansion, which is balanced but transformerless. This output is before the MSTR Fader.
- 2 additional Balanced inputs to the MIX bus via 1/4" jacks. These can be used to insert other mixers into the Tonelux mix bus, or they can be used as the inputs from other OTB-16 mixers for expansion.
- The power for the OTB-16 can be 120 or 230 volts AC 50/60 Hz.