Manual-4
SRM 66 Connection
Balanced Operation
Connect the ‘+’ to ‘+’, ‘–’ to ‘–’, and shield to shield. Use only
when driving from a true balanced source and driving to a true
balanced destination — either transformer coupled or active
drive.
Unbalanced Operation
To avoid nasty side effects such as hum and noise – which are
consequences of unbalanced operation – keep cable lengths as
short as possible. For lengths longer than ten feet, use a trans-
former such as a Rane BB 44x.
Coming from an unbalanced source, the SRM 66’s Input
uses two conductors plus a shield; connect ‘+’ to ‘+’, the unbal-
anced source ground to ‘–’, and the cable shield to the SRM 66’s
ground.
Going to an unbalanced device using a single conductor plus
a shield, connect ‘+’ to ‘+’, leave ‘–’ unconnected and connect the
cable shields at both ends to ground.
Combination Operation
For combined balanced and unbalanced operation, use
whichever half of the above instructions apply for each end. See
the “Sound System Interconnection” RaneNote included with
this manual for more information on cabling and grounding
requirements.
Chassis Grounding
If after hooking up your system it exhibits excessive hum or
buzzing, there is an incompatibility in the grounding inside a
unit(s) or between units somewhere. Your mission is to discover
how your particular system wants to be grounded. Try these
things:
1. Try combinations of lifting grounds on units that are supplied
with ground lift switches or links. Other than in your own
home, it is illegal and unsafe to use 2-prong to 3-prong AC
line cord cheaters, even though this is a common (short term)
remedy. Using such “cheaters” can (and has been known to)
electrocute or kill people. [Ace Frehley and Keith Richards
survived; Keith Relf (The Yardbirds) and John Rostill (The
Shadows) did not.]
2. If your equipment is in a rack, verify that all chassis are tied to
a good earth ground, either through the AC line cord ground-
ing pin (3
rd
prong) or the rack screws to another grounded
chassis.
3. Units with outboard power supplies may
not
ground the chas-
sis through the line cord. Make sure these units are grounded
either to another chassis which is earth grounded, or directly
to the grounding screw on a grounded AC outlet cover.
Please refer to the RaneNote “Sound System Interconnection”
(elsewhere in this manual) for further information.
FP Lock
The recessed FP LOCK switch (on the rear) locks out all
front panel control except for Group Levels and Memory Recall.
With FP LOCK engaged, the SR 1L Remotes are able to control
Group Levels, and all Edit Pages are viewable but not editable.
