GLENSOUND ISDN MIXERS
Glensound equipment has been in extensive use throughout in the UK broadcast market for many years. Although not occupying a high profile position, they have been supplying specialist and customised equipment to the major UK broadcasters such as the BBC over that period. That close association has meant that Glensound have a good appreciation of the needs of the broadcast market.
The GSGC25 is a very simple ISDN unit that contains two G.722/G.711 codecs. Each of the three mic/line inputs can be fed with 12v phantom power.
Calls can be made using the keypad and levels monitored with a 7-segment LED display. Comprehensive headphone monitoring is available from four sources, each with its own level control. The headphone amp output is on three front panel A/B gauge headphone jack sockets, one wired to only the left channel of the headphone amp, one wired only to the right channel & one wired to both. A record output (on a rear panel ‘bantam’ jack) is a mix of the output of the GSGC25’s mixer and the return programme cue line.
The GSGC25 can be powered from 2 ‘D’ cells (approximate battery life of 4 hours) or an external plug-top power supply. If it is being powered from the external supply and the supply fails the batteries will automatically take over. A front panel LED shows when the GSGC25 is switched on and flashes to indicate when battery level is low.
The GSGC5 audio section consists of a 3 mic + 1 line input mixer, with two headphone monitor outputs, each of which can set its own mix of desk output and cue return. This section can be used with conventional landlines. On the ISDN section, calls may be made utilising internal codecs via an approved integral terminal adapter. All audio inputs and outputs are via front panel mounted XLRs, with headphone jacks. ISDN connection, X.21 interface on ‘D’ connector, external DC input and power switching are on the rear.
A sloping top panel contains sensibly arranged user controls separated into two logical sections, audio control and call set-up/configure control. Basic operating instructions in English are also clearly printed on the control panel. Audio controls include 4 channel rotary pots, two sets of headphone controls and a basic LED column PPM. Internally, a compressor limiter is inserted after the PPM. The keyboard allows dialling and a number of configuration options, including selection of incoming/outgoing B channel, memory dialling, sub-address mode and multiple subscriber numbering mode.
Units can operate on internal alkaline batteries (3 ×D size) for over 8 hours or from an external 6-9VDC source with 500mA capacity. They are supplied in a polypropylene transit case.
Another particularly useful feature of the GSGC5 is that it will automatically sense which type of codec (MPEG, apt-X or G.722) is at the other end of the line, adjust itself to match the equipment, and proceed accordingly. Although it operates using one ‘B’ channel only, the unit can be configured to answer any ‘B’ channel of an ISDN2 installation.
A restricted facilities version, with one mic and one line input and a single headphone output is available, the GCGC4. Its ISDN facilities are unchanged.
A wider range of options are available for the GSGC5 and GSGC4 equipment. These include single codec versions (including ISO/MPEG Layer 2) and the GSGC6 1U rackmount version. The latter have input and output on XLR, and exclude the mixer section. The modules for these are known as the GSGC17 series cards. Further information is available from our Technical Support Department.
||3 ×’D’ alkaline cells or external 6-9VDC @ 600mA
||235(w) ×227(d) ×90(h)mm