BC1 Small Format Broadcast Consoles

TelCo Input Module

The BC1-IT, TelCo input module, is a mono device that contains all necessary features for the integration of telephone lines via an external telephone hybrid into the small format broadcast mixers BC1. It has two line level inputs, offers the same processing features as the BC-IM1 mono channel strip. The remote section is optimized for the control of telephone systems. A sopisticated n minus system makes handling of any kind of telephone line integrator very easy. Like all BC1 modules, the BC1-IT offers ultimate + 30 dBu headroom throughout the entire signal chain and a switched insert section that operates at nominal level, also with headroom of + 30 dBu.

The Input Section has two separate line level inputs that can be implemented electronically balanced or transformer floating. The input can handle levels of + 30 dBu. The LINE2 switch select the second input. The gain control has a range of +/- 20 dB. The 0 dB center detent is calibrated.

The Processing Section combines a sweeped hi-pass and low-pass filter and a 4 band equalizer with 2 fully parametric bands. Filters and EQ operate independently. In addition, there is a switched, electronically balanced insert section that can be switched pre or post the equalizer.

The Filter section has independent pots for the hi-pass and the low pass filter. The control ranges are from more than 20 kHz to 2 kHz for the low-pass filter and from less than 20 Hz to 600 Hz for the hi-pass filter. Both filters are 'maximum flat', 12 dB/oct. steeprate, active filters. The FILT switch insert the section into the signal chain. The Equalizer is a 4 band version with 2 fully parametric mid bands. All bands have a gain control range of +/- 20 dB. The fully parametric bands have a sweep range from 250 Hz to 20 kHz for the hi-mid and from 50 Hz to 4 kHz for the low mid band. The Q-factor can be controlled from 3 octaves to less than a third. The low EQ is implemented as a RC based, very soft bell that has a center frequency of 50 Hz or 120 Hz respectively. The implementation of a bell type filter as low EQ avoids the boost of subsonic noise without using the hi-pass filter with hi gain settings. In total, this version offers a much better phase overall phase response than the use of both, shelving low EQ and hi-pass filter to limit subsonic noise. A switch determines the center frequency. The Hi EQ operates as a soft, 6 dB steeprate shelving filter that reaches the maximum at 20 kHz. The 10 kHz switches this characteristic to a very soft bell with a center frequency of 10 kHz.

The electronically balanced, switched Insert is located post the EQ and can be routed pre EQ, post Filters with the PRE switch. The insert output is always available on the connector panel. The insert is switched into the signal chain by the INS button. The entire insert section can handle levels of + 30 dBu.

The Aux Sends 1 to 4 are default to post fader and have independent PRE switches.

The Fader is a 100 mm, conductive plastic fader with with 10 dB maximum gain. The output of the fader section drives the routing matrix via the Cut circuit and the Pan-Pot that is carried out as standard mono to stereo panoramic control with 3 dB center attenuation. In addition to the local cut control switch, two cut groups can be selected by separate switches. The output of te pan-pot drives the routing matrx that allows the selection of the program master bus and the 12 audio subgroups in stereo pairs.

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IM - Mono Module
IS - Stereo Module
IT - TelCo Module
SG - Group Module
PG - Master Module
CT - Monitor Module
TB - Playback/Talkback
Block Diagram
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TelCo Input Module IT