Swiss Army Mixer-
Figure 7. Level Controls for two MA 3 Amplifiers
Figure 8. Stereo Headphone Mixer
Applications
The SM 26B is unusually versatile in its applications.
With the capability to mix 6 Mono Inputs down to one
stereo pair, or split one stereo pair into 6 separate Out‑
puts. or condition 6 Inputs by adding gain or attenua‑
tion—all of this either balanced or unbalanced and able
to drive 600 Ω lines, makes the SM 26B truly a “Swiss
Army Mixer”. Further, any combination of the above
can occur at the same time, in the same unit.
1 In / 3 Out +
3 In / 3 Out Combination
For instance. you can split one signal into three sepa‑
rate Outputs with individual LEVEL controls and
use the remaining three MONO INS and OUTS as
buffer/line driving amps. creating a 1‑to‑3 / 3‑to‑3
combination.
6 In / 6+2 Out
Another interesting combination is to use the SM 26B
as a 6 In / 6 Out level translation amplifier (infinite cut
to +12 dB boost) and also mix the 6 Mono Inputs down
to one stereo pair with the PAN pots. The stereo Out‑
put appears at the LEFT and RIGHT MIX OUTPUT
jacks.
6+2 In / 2 Out
Or bring 6 Mono and 1 Stereo pair into the
SM 26B and add the 6 MONO INs to the stereo pair
via the PAN pots. You now have a 6+2 In / 2 Out situa‑
tion with the 6 Mono Inputs still available as 6 buffered
Outputs if needed.
Stereo Headphone Mixer
Figure 8 shows how the SM 26B can be used as a
6 In / 2 Out stereo mixer driving the HC 6 Headphone
Console. Six Mono Inputs are brought into the SM 26B
where they are mixed together via the PAN pots to cre‑
ate a stereo output signal at the LEFT and RIGHT MIX
OUTPUT jacks. These lines are connected to the MAS‑
TER LEFT and RIGHT INPUT jacks of the HC 6 where
they drive the six stereo headphone amplifiers.
Zone Amplifier Level Controls
Adding individual remote level controls to the MA 3
Multichannel Amplifier is easy with the SM 26B as dia‑
grammed in Figure 7. The mono signal is applied to the
LEFT INPUT jack and the 6 balanced MONO OUTS
are connected to the balanced inputs of the MA 3. Ro‑
tating all MIX pots fully CCW routes the Input signal
to each of the MONO OUTS. Each individual Output
is adjusted by its respective channel LEVEL control.
If separate sources are connected to the LEFT and
RIGHT INPUT jacks then the individual MIX pots
will determine which source (or combination of both)
is presented to each of the MONO OUTS. Full CCW
rotation gives Left only; full CW rotation gives Right
only; and the middle position gives equal amounts of
Left plus Right.
LEFT INPUT
SM 26B
MA 3
MA 3
6
6
5
5
2
2
4
4
3
3
1
1
LEFT INPUT
1
2
3
4
5
6
HC 6
HEADPHONE 6
HEADPHONE 5
HEADPHONE 2
HEADPHONE 4
HEADPHONE 3
HEADPHONE 1
SM 26B
6
5
2
4
3
1
LEFT MIX OUTPUT
RIGHT MIX OUTPUT
RIGHT INPUT
