- 5 -
CM-680 INSTRUCTION MANUAL Ultra Stereo Labs, Inc.
- 10 -
CM-680 INSTRUCTION MANUAL Ultra Stereo Labs, Inc.
CM-680 Front Panel
PROCESSOR AMPLIFIERS
VOLUME
2
8
3
1
7
9
10
0
4
5
6
CHANNEL SELECT
VU
TEST
POWER
L
C
R
SW
Ls Rs
BSl BSr
CM-680
EIGHT CHANNEL MONITOR/XOVER
+3
+2
+1
0
-1
-3
-5
-7
-10
-20
-30
-40
12345678 9
1. Channel select buttons - pressing a Channel Select Button causes the corresponding LED to illuminate
and the signal from that channel to be monitored. Any combination of eight channels can be selected.
2. Internal Digital or Analog Crossover Access Cover.
3. Crossover Bypass Switch - Switching this will cause the internal crossover to be bypassed or engaged
and the condition will be indicated by its appropriate LED.
4. Volume Control - controls the volume of the internal or external speaker. The volume control has
no effect on the VU Bargraph display.
5. Processor/Amplifier Selector Switch - selects either the inputs from the cinema processor or power
amplifiers for monitoring.
6. VU Bargraph - displays the level of the selected channels. The VU Bargraph may be calibrated by
the rear panel trim adjustment (Figure 2). The VU Bargraph operates independently of the volume
control (4).
7. Test Jack - permits monitoring of the audio output of the CM-680. Inserting a mono or stereo 1/4
phone plug here disables the internal speaker and routes the audio output to the Test Jack. Do
not connect any device here with less than 8 Ohms impedance.
8. Internal Speaker
9. Power Switch
Pin # Function
1 GND
2 Left
3 N/C
4 N/C
5 Center
6 N/C
7 N/C
8 Right
9 N/C
10 GND
11 GND
12 GND
13 N/C
14 GND
15 Left LF
16 Left HF
17 GND
18 Right LF
19 Right HF
20 GND
21 Center LF
22 Center HF
23 Surr L
24 Surr R
25 Sub
Main
Processor
Outputs
N/C
N/C
Bsl -
N/C
N/C
Bsr -
Chassis Gnd
N/C
N/C
Ls -
Rs -
N/C
N/C
N/C
N/C
Bsl +
N/C
N/C
Bsr +
N/C
N/C
N/C
Ls +
Rs +
N/C
Optional
Processor
Outputs
Function
DB-25
Connector Pinout
Setting Monitor and Bargraph Levels:
Set the processor main fader and amplifier levels so the house speakers
are playing back at the normal listening level. Select some source material
like pink noise.
Set the Processor/Amplifier switch to Processor. With the monitor
volume to 7, adjust the Processor trimpot for a comfortable listening
level. Set the bargraph trimpot for a reading in the middle range.
Set the Processor/Amplifier switch to Amplifier, adjust the amplifier
trimpot so the level matches the processor level.
Figure 1
Figure 5
CM-680 HD 15 pin outs
Typical per connector
Pin # Name Pin # Name Pin # Name
1 Band A (1), - 6 Chassis Gnd 11 Band B (2), -
Signal Signal
2 NC 7 Band A (1), + Signal 12 NC
3 Band A, Vmon 8 Band B (2), + Signal 13 Band B, Vmon
(Amp returns) (Amp returns)
4 Band A, Imon 9 NC 14 Band B, Imon
5 NC 10 Signal Ground 15 NC
