ALLEN & HEATH GS1 Service Manual page 6

Replug and repeat for Channels 2 to 8.
5.4 Plug CD L and R into Channel 9/10 STEREO RTN jack sockets. Raise and test the RTN Level and Pan
pots.
Replug and repeat for Channels 11/12 to 15/16.
5.5 Plug CD L and R into Channel 9/10 Stereo Input jack sockets. Raise channel Fader to '0' and press L-
R. Test Fader, Hi/Lo switch, EQ, Pan and Channel On functions.
5.6 Plug CD into Channel 1 Line input jack socket. Raise Fader to '0', route to 1-2. Link GROUP Out 1
phono socket to TAPE RTN In phono socket. Raise TAPE RTN Level and listen to music quality. This
tests the channel routing to Group 1 out (listened to via TAPE RTN).
Test Channel 1 routing to all the groups by replugging the phonos.
5.7 Plug the amplifier into AUX Out 1. Use Channel 1 Aux send 1 to test the Aux output with the AUX master
pot raised to maximum.
Replug the amplifier and test AUX 2 to 5 outputs.
5.8 Replug the amplifier into the Mon Amp L and R outputs, raise the Monitor Level pot and Listen to the
Channel 1 Line input routed to L-R. Press Channel 2 PFL. The signal should be cut off. Set Channel
1 Fader to minimum and press Channel 1 PFL. The signal should reappear.
Replug the CD and test the PFL function of all the channels.
5.9 Plug CD into 2-TRACK In L and R. Press the 2-TRACK monitor switch and check music quality.
5.10 Press the Monitor Output Mute switch. The signal should be muted. Plug a pair of stereo headphones
into the GS1 Headphones jack socket and check signal quality.
6. Noise test
Remove the test signal source. The following tests listen to the residual noise generated by the GS1
electronics. This is well below the normal signal level of the console and represents the impressive signal-
to-noise performance of the GS1.
With the amplifier gain turned up listen to the noise under the conditions set out below.
WARNING: Because of the high amplifier gain required avoid switching signals to the outputs
while listening to noise. Always turn the amplifier down when replugging the output connectors.
Listen for a smooth residual hiss (white noise). Slight hum may be present on certain outputs but this
should be well within the hiss. Excessive hum, buzzing, clicks and popping may represent a problem.
6.1 Mon Amp output, all faders down, channel Gains min. Press each channel PFL in turn listening for
channel stage noise.
6.2 Channel Gains max. Press each PFL. Listen for channel preamp noise.
6.3 Replug amplifier to 2-TRACK Out L and R. Listen to noise with L-R fader down.
6.4 Raise L-R fader to maximum, all channel faders down, no channels routed.
6.5 Route all channels to L-R, raise faders to maximum. Switch each Channel On in turn.
6.6 Replug the amplifier to each GROUP and AUX output in turn listening for residual noise quality. Do this
with no groups routed, all channel AUX send pots down, and master AUX send pots maximum.
This completes the test.
Check that the unit is clean, controls reset with faders at maximum (as required for packing). Repack carefully in the
original packing complete with accessories.
Complete the service log with serial number and test details. Inform A&H immediately if any quality problem is noted.
ALLEN & HEATH
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S1SM1