[. . . ] The line input has an effective overall gain range of -10 to +35dB, allowing the valve stages to be fully driven from line level signals in the range -20 to +20dBu. A front panel mounted auxiliary jack socket for each channel allows mic or line level inputs to be easily connected to the compressor. An insertion point is provided in the sidechain circuit to allow an equaliser or other processor to be used for frequency conscious compression, etc. The insertion point is unbalanced, at a nominal operating level of -2dBu. [. . . ] A switch on the rear panel allows the output to be matched to equipment at a nominal operating level of +4dBu or -10dBu. Most professional equipment requires +4dBu (approximately 1. 2V rms), but some small mixing consoles, portable tape recorders or domestic audio equipment require -10dBu (approximately 225mV rms). The switch should be set to the position which results in the best signal to noise ratio, whilst preserving sufficient headroom. An unbalanced line output is provided for each channel, on a 0. 25" mono jack socket. - Tip = Signal Phase ("+" or "hot"). - Screen = Ground. This heat should be allowed to dissipate by convection through the grill in the front panel, which must not be obstructed. Do not locate the unit where it will be subject to external heating, for example in the hot air flow from a power amplifier, or on a radiator. The compressor may be free standing, or mounted in a standard 19" rack. The rear panel connectors are identified in fig. 3. OPERATION. Front Panel. Ensure that the correct input connector, mic or line, is being used and that the front panel switch is set to the appropriate position. Note that both mic and line inputs may be connected at the same time, but only one is selected. The input selector switch selects between the line input, mic input, mic with +48V phantom power (signalled by a red LED), and the Aux input. CAUTION: Switching phantom power on, or plugging a microphone in with phantom power applied, may cause a click or thump in your loudspeakers. To prevent this happening, ensure that the system gain is set to minimum (e. g. on your mixing console fader or power amplifier), before operating the switch or plugging in a microphone. If the gain required is not known, set the control to minimum with the EQ by-passed, and gradually increase the gain until the required output level is achieved. The front panel auxiliary input sockets may be switched between high level signals ("Keyboard") and low level pick-ups ("Guitar"), and are provided with an input gain control. Note that the channel gain controls remains operative when the Aux input is selected. The two aux input sockets may be used, for example, for a stereo keyboard. The compressors may be operated independently, or linked for true stereo operation. Aux A input is also normalled to the B input, so both channels may be driven from a mono input (guitar, etc). With different channel gain settings, one channel may be lightly compressed, whilst a higher degree of compression is applied to the high gain channel, resulting in stereo effects from a mono input. Compressor Operation. [. . . ] Return input impedance 10Kohms. Power Requirements: Rear panel selectable for 220-240V 50Hz or 110-120V 60Hz operation. Weight: 6Kg. In line with a policy of continuous development, the above specifications are subject to change without notice. SERVICE Should the compressor require service, it must be taken or posted to an authorised dealer. Please retain the original packing for possible future use, and ensure the unit is suitably protected during transit. The manufacturer cannot accept responsibility for damage caused during transportation. [. . . ]