Swiss Army Mixer-
Block Diagram
A complete block diagram of the SM 26B appears as
Figure 1. (Get your eyeglasses, you may need them.)
Stereo input pairs are accommodated by the individual
LEFT and RIGHT INPUT jacks. Expansion or “daisy
chaining” is possible through the use of the parallel
EXPAND OUT jacks. A dual ganged MASTER INPUT
LEVEL control sets the gain from off to +12 dB for both
Inputs.
From here, the Master Inputs feed a left and right
mixing bus to each of the six MIX pots, as well as going
straight through to the MASTER OUTPUT LEVEL
control stage which feeds the Left and Right Mix
Outputs. The Output from each of the Mix pots feeds
the individual Mono Channel Level stages through a
Figure 1. SM 26 Complete Block Diagram
switching contact associated with the MONO IN jack.
(The jacks are drawn in their open, i.e., unused state.
Inserting a plug into the MONO IN jack causes the
auxiliary switch to change position.) The combined left
and right signals go to each of the channel Outputs.
Individual mono inputs enter through the MONO
IN jacks, through the (now closed) auxiliary switch to
the +12dB gain stage where it feeds the MONO OUT
jack. The PAN pot splits the signal into two signals that
feed the LEFT and RIGHT MIX OUTPUTs via the
Master Outputs.
It’s really quite simple. Now let’s look at specific con‑
figurations, leaving out the unused circuitry.
