Summing mixer with quality op-amps.
The OTB16 is a 16 channel 1U mixer with 16 balanced inputs and the 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 two 8-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.
Also on the rear panel are two 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.