Speck Electronics SSM - Manual (Page 49)

Chapter 4 Operation Section
For SSM systems incorporating mono input channels, the Pre Fader
Listen (PFL) level may be adjusted with this recessed trim pot. Use care
when inserting a screwdriver as other components could be damaged.
These unbalanced 1/4" T.S. phone type jacks are the left/right outputs
for the stereo program master. The signal present at these jacks is
adjusted by the Program Master Control on the front panel.
The use of these connectors does not affect the operation of the balanced
XL connectors.
The balanced left and right program feeds utilize the highest quality
nickel core output transformers for hum rejection and sonic purity. The
signal present at these connectors is adjusted by the Program Master
Control on the front panel.
The left and right program feed is capable of driving up to three high
impedance bridging inputs simultaneously. The program feed
connectors are available for interface to the input of an external console,
stereo tape recorders etc.
The use of the balanced XL connectors does not affect the operation of
the unbalanced 1/4" connectors.
As long as the potential for an electrical disparity exists between the
Model SSM and any interconnected equipment not on the same AC
circuit as the SSM (eg: a cue feed from a control room console),
transformers will remain a key element in resolving some of the primary
audio problems that may result such as unwanted hums and buzzes.
Speck has provided input and output transformers
in key positions on the mixer; cue and click inputs and the left/right
program outputs. For more specific user information, refer to the
sections on cue and click returns and program feeds.
The following chart represent the pin assignment for the balanced
program feed XL connectors.
10. Program Feed Jacks
(Unbalanced)
Transformer Isolation
11. Program Feed Connectors
(Balanced XL)
Program XL Pin Configuration
44
9. PFL Level Trim Control
PIN 1 - GROUND
PIN 2 - HIGH SIGNAL
PIN 3 - LOW SIGNAL