Rane SM 26B User manual

Manual-1
OPERATORS MANUAL SM 26B
SPLITTER MIXER
Quick Start
Realizing that in most areas there are laws against reading owners manuals, and that reading them under the blankets at night
with a flashlight makes you feel stupid, we therefore provide this brief, yet informative, description of how to use the SM 26B just in
case your batteries are low and your mother is about to come in the room.
To achieve a quick understanding of the SM 26B, think of it as a six channel mixer with faders and pans only. Or think of it as a
2-to-6 channel splitter with output level controls and a mix knob (to control how much of which input goes to which output). If you
get that, you may stop here as long as you know how to hook up the power supply.
As a six channel mixer, MONO IN 1 through 6may be placed on the Right or Left bus or both, in any amount. e respective
LEVEL knobs on the front of the unit serve as the mixer’s faders, the adjacent PAN controls place the channel’s signal into the stereo
field. As an effects mixer or line level expander for a larger mixer, set up the LEVELS and adjust the PANS. e MASTER OUT-
PUT LEVEL adjusts the overall level of the mix at the Master Outputs.
As a splitter, place one or both input signals into the LEFT and/or RIGHT Inputs. Select the Input(s) to be placed at each of the
six MONO OUTs by rotating the MIX/PAN control to the proper position. Set the individual channel LEVEL controls for proper
output level. e Master INPUT LEVEL control on the front adjusts both Right and Left Input signal levels together.
Never connect anthing except an RS 1 or other approved Rane AC power supply to the red thing that looks like a tele-
phone jack on the rear of the SM 26B. is is an AC input and requires some special attention if you do not have an operational
power supply exactly like the one that was originally packed with your unit. See the full explanation of the power supply require-
ments elsewhere in this manual.
WEAR PARTS: is product contains no wear parts.
MIXER
SPLITTER
100
2
4
8
6
100
2
4
8
6
1010
6
2
6
2
100
2
4
8
6
100
2
4
8
6
100
2
4
8
6
100
2
4
8
6
100
2
4
8
6
100
2
4
8
6
1010
6
2
6
2
1010
6
2
6
2
1010
6
2
6
2
1010
6
2
6
2
1010
6
2
6
2
MASTER
OUTPUT
234561
POWER
MASTER
INPUT
SM 26B
LEVEL LEVEL LEVEL LEVEL LEVEL LEVEL LEVELLEVEL MIX / PAN MIX / PAN MIX / PAN MIX / PAN MIX / PAN MIX / PAN

Manual-2
Front Panel Description
1MASTER OUTPUT LEVEL controls the amount of signal at the MIX OUTPUT jacks. It does not affect the level of any of the
six MONO OUTs. is control changes the gain of the output stages. is allows an increase in headroom to eliminate over-
loading due to excessive combined signal from one or more Inputs. Range of gain is from Off to 0 dB (unity). Refer to the block
diagram below.
2Mono Input LEVEL controls the Level of signal through each particular channel. When fed from the MONO IN jack, each
stage has a gain range from Off to +12 dB minimum, allowing level matching of -10 dBV equipment to +4 dBu gear. When fed
via the LEFT & RIGHT INPUT(s), these LEVEL controls automatically limit to a maximum of unity gain to accommodate the
+12dB available from the Left & Right Input gain stages.
3MIX / PAN serves two different functions:
MIX: When used as a SPLITTER, this controls the mix of Left and Right Master Input program to each channel’s MONO
OUT.
PAN: When used as a MIXER, this control pans the Mono channel Input between the LEFT and RIGHT MIX OUTPUTS.
4MASTER INPUT LEVEL sets the gain of the Left & Right Master Input stages, with a range of Off to +12 dB. In the splitting
mode, this controls the Level of all Mono channel Outputs at once (i.e., those which do not have a separate input).
5POWER switch & indicator: Two guesses... When this yellow LED is lit, the SM 26B is ready to go.
MIXER
SPLITTER
100
2
4
8
6
100
2
4
8
6
1010
6
2
6
2
100
2
4
8
6
100
2
4
8
6
100
2
4
8
6
100
2
4
8
6
100
2
4
8
6
100
2
4
8
6
1010
6
2
6
2
1010
6
2
6
2
1010
6
2
6
2
1010
6
2
6
2
1010
6
2
6
2
MASTER
OUTPUT
234561
POWER
MASTER
INPUT
SM 26B
LEVEL LEVEL LEVEL LEVEL LEVEL LEVEL LEVELLEVEL MIX / PAN MIX / PAN MIX / PAN MIX / PAN MIX / PAN MIX / PAN
1 2 3 4 5

Manual-3
Rear Panel Description
1Master LEFT & RIGHT INPUTS are balanced Tip-Ring-Sleeve (TRS) ¼" Inputs. ese Inputs feed all six MONO OUTs
when all MONO INs are not used. Connecting to individual MONO INs disconnects that channel from these Inputs (refer to the
Block Diagram found on the SM 26B Data Sheet). For unbalanced operation use a standard mono ¼" plug; for balanced opera-
tion use a TRS (stereo) ¼" plug wired as follows:
TIP is signal + (connect to Pin 2 on a 3-pin connector).
RING is signal - (pin 3 in a 3-pin connector).
SLEEVE is chassis ground.
2LEFT & RIGHT EXPAND OUTS: ¼" TRS jacks are connected in parallel with the Master LEFT & RIGHT INPUT jacks,
allowing two or more SM 26Bs to be daisychained for multiple splitting. Simply connect these EXPAND OUTS to the LEFT &
RIGHT INPUTs of another SM 26B; there is no limit to the number of expansions possible with the SM 26B.
NOTE: ese Expand Outputs are not buffered from the Master Inputs. erefore it is not possible to mix both balanced and
unbalanced lines in the same channel between several units: once the ring and sleeve are shorted anywhere in the chain (by using a
mono plug) the entire line becomes unbalanced.
3MONO INPUTS are TRS ¼" jacks which accept either balanced or unbalanced mono signals. ese are switching jacks which
automatically bypass the Master LEFT & RIGHT INPUTs whenever a plug is inserted (see the Block Diagram in the SM 26B
Data Sheet). Follow wiring conventions as in 1.
4MONO OUTPUTS: ¼" TRS jacks deliver either a conventional unbalanced output (use mono cords), or a balanced output (use
TRS cords). Follow wiring conventions as in 1.
5LEFT & RIGHT MIX OUTPUTS: ese balanced TRS ¼" outputs are controlled by the MASTER OUTPUT LEVEL
control. ey are fed either by the Master LEFT & RIGHT INPUTS (respectively) or by any of the six MONO INPUTS, or a
combination of both (see e Swiss Army Mixer RaneNote). Follow wiring conventions as in 1.
6Remote power supply input: e SM 26B is supplied from the factory with a model RS 1 Remote Power Supply suitable for con-
nection to this input jack. e power requirements of the SM 26B call for a 18-24 volt AC center-tapped transformer only. is is
not a telephone jack. Never use a power supply with your SM 26B other than the one supplied or a Rane approved replacement.
7Chassis ground point. A #6-32 screw is used for chassis grounding purposes. See the Chassis Grounding note below.
CLASS 2 EQUIPMENT
MADE IN U.S.A.
RANE CORP.
300mA
POWER
SM 26B
ACN 001 345 382
ALL INPUTS AND OUTPUTS ARE BALANCED — TIP=POS RING=NEG SLEEVE=CHASSIS GROUND
EXPAND
OUT
INPUT
LEFT
EXPAND
OUT
INPUT
6
RIGHT
543
MONO IN
12 1 6 5 4 3 2
MONO OUT
LEFT RIGHT
EXP. OUT INPUT EXP. OUT INPUT
6 5 4 3 12 1 6 5 4 3 2
LEFT RIGHT
MIX OUTPUT
6 1 2 1 2 3 4 57
CHASSIS GROUNDING
If after hooking up your system it exhibits excessive hum or buzzing, there is an incompatibility in the grounding configuration
between units somewhere. Your mission, should you accept it, is to discover how your particular system wants to be grounded. Here
are some things to try:
1. Try combinations of lifting grounds on units that are supplied with ground lift switches or links.
2. If your equipment is in a rack, verify that all chassis are tied to a good earth ground, either through the line cord grounding pin or
the rack screws to another grounded chassis.
3. Units with outboard power supplies, such as the SM 26B, do not ground the chassis through the line cord. Make sure that these
units are grounded either to another chassis which is earth grounded, or directly to the grounding screw on an AC outlet cover by
means of a wire connected to a screw on the chassis with a star washer to guarantee proper contact.
Please refer to the “Sound System Interconnection” RaneNote for further information on system grounding.

Manual-4 107370
©Rane Corporation 10802 47th Ave. W., Mukilteo WA 98275-5098 USA TEL [phone] FAX [phone] WEB www.rane.com
Operating Instructions
Since numerous applications exist for the SM 26B, no single
set of operational procedures control its use. e SM 26B Swiss
Army Mixer RaneNote (included) explores the many configu-
rations of the SM 26B in depth, and you should peruse it for
applications information.
INTERNAL JUMPER OPTIONS
ere exist within the SM 26B some signal routing options,
requiring removal of the top cover to move some jumpers.
If an SM 26B needs to have an additional set of independent
outputs, as in a 2x4 stereo distribution amplifier (see Swiss Army
Mixer, Figure 10), the LEFT and RIGHT MIX OUTPUTS
can be used in addition to the 6 MONO OUTS. Normally,
the LEFT and RIGHT MIX OUTPUTS produce the sum mix
of all 6 LEVEL and PAN controls. To break any channel away
from the Mix Output bus, internal jumpers have been provided.
ese are located behind the MIX/PAN controls for each chan-
nel. J3 connects MONO OUT 1 to the mix bus. J6 connects
MONO OUT 2, J9 connects MONO OUT 3, and so on — see
the board layout below.
SM 26B Connection
When connecting the SM 26B to other components in your
system for the first time, leave the power supply for last. is
gives you a chance to make mistakes and correct them before
damage is done to anything fragile.
As you have no doubt noticed, all Inputs and Outputs on the
SM 26B’s rear panel are ¼" connectors. e Inputs and Outputs
are active balanced on Tip-Ring-Sleeve (TRS) jacks which allow
the flexibility of connecting in either a balanced or unbalanced
fashion. If unbalanced operation is your preference, the simplest
way to accomplish this is through the use of tip-sleeve ¼" con-
nectors. e ring is not essential unless balanced operation is
required. Be aware that if you are running unbalanced and using
TRS connectors with both tip and ring, the ring and sleeve must
be shorted together. Failure to do so on the inputs results in a
gain loss of 6 dB.
Balanced operation requires that TRS plugs be used. e tip
is hot (+), the ring is return (–) and the sleeve is ground. Rane-
Note, “Sound System Interconnection” (included here) contains
some great pictures to aid your interconnect ventures.