Telex Q II - FOH specifications Signal Path, Reset Circuit, Solo System

THE INPUT MODULE

THE SIGNAL PATH

The Q2 is equipped with a microphone and a line input selected by a switch and controlled by the same pot. The microphone input may have a 20dB pad switched in and a phantom supply can be fed to the microphone from each module. From here the signal enters or by-passes a phase reverse circuit which is simply a unity gain inverting stage. The signal then enters or by-passes the sweepable high pass filter. At this point the equaliser can be selected pre or post the insert point and from here the signal enters the cut SSM followed by the fader, the fader buffer stage and the pan circuit before going to the routing switches. A VCA version of the module will allow for VCA level control and VCA muting.

THE RESET CIRCUIT.

A reset for the module logic is given by the RC network formed by C41 and R142. On power up C41 will charge through R142 causing TR1 to switch on. This applies a low to the SET input of the flip flop and a high to the reset input causing Q bar to go high giving a channel ON condition. The RESET line is also fed to the SOLO enable circuit.

THE SOLO SYSTEM

The Q2 solo system is a little more comprehensive than in other consoles and there are some novel features about the way in which it operates.

The SOLO button can be pressed fleetingly and the solo will latch until the button is pressed for a second time. If the button is depressed for a longer period then the solo will not latch but will release as the solo button is released. There is also a facility for all solos to be cleared by the operation of a master button on the console.

The heart of the system is IC11 a dual D-Type flip flop. Normally the reset pin will be held low and under this condition the state of the Q output will toggle with each operation of the solo switch.

Q2 OPERATIONAND MAINTENANCE MANUAL 9601 68