User manual TL AUDIO EQ-2

[. . . ] T L Audio User Manual EQ2 VALVE EQUALISER Tony Larking Professional Sales Limited, Letchworth, England. Tel 01462 490600, Fax 01462 490700. INTRODUCTION The T L Audio EQ2 Parametric Valve Equaliser combines classic valve techniques with low noise solid state circuitry to produce a unit offering sweepable high and low pass filters plus four bands of fully variable equalisation on each of its two channels. Both channels feature a line level input, plus a mic input with switchable 48V phantom powering. Further flexibility is provided from a front panel auxiliary input and stereo operation mode. [. . . ] The outputs are via balanced, 3 pin male XLR connectors. The mating connectors should be wired as follows: - Pin 1 = Ground (screen), - Pin 2 = Signal Phase ("+" or "hot"), - Pin 3 = Signal Non-Phase ("-" or "cold"). If an unbalanced output is required, pins 1 and 3 should both be connected to ground. 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. The unit generates a small amount of heat internally, mainly due to the valve heaters. 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 EQ 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 EQ may be free standing, or mounted in a standard 19" rack. The rear panel connectors are identified in fig. 2. OPERATION. Front Panel. The front panel controls are identified in fig. 3 Input Stage. 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. +48V phantom power is available at the mic socket, selected by a front switch and signalled by a red LED. Phantom power should only be used in conjunction with suitable microphones. CAUTION: Operation of the phantom power switch, 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. [. . . ] Instrumentinput on front paneljack, switchable high/low gain for guitar or keyboard. Mic input balancedon XLR, with switchablephantompower. EIN -127dBu(150 ohms, 22Hz-22KHz). Input gain range+ 16dBto +60dB (Mic), -22dB to +22dB (Line). Filters: Continuously variable, individually switchedhigh and low passfilters, 12dBper octave. LF cut frequencyrange 30Hzto 1KHz, HF cut frequencyrange 1KHzto 25KHz. Equalisation: Four bandsper channel, individually switched, plus overall EQ ON switch. [. . . ]