Unconditional Tuning ("Auto Tune"); The Incremental Control - Moog THE SOURCE Owner's Manual

UNCONDITIONAL TUNING ("AUTO TUNE")
It is possible that, after warm-up and stabilization, the two audio oscillators in The Source may not be nominally
tuned to exact unison.
A procedure to correct this is described in Tuning Up, on page 3 . This procedure involves unconditional access
to oscillator 2 and should be explained further.
Simultaneously touching |8||t|2|g and |tggU Level connects the incremental control to the master tuning input
for Osc 2. Turning the incremental control will adjust the tuning of Osc 2, relative to Osc 1, without changing the
stored values for Osc 2 interval for each voice. The range of adjustment in this mode is approximately 1 semitone.
The factory programs are voiced with careful attention to the tuning of Osc 2. Osc 2 is generally tuned to some
consonant interval — an octave, a major tenth, etc. These interval values are set in memory on the assumption that
Osc 1 and Osc 2 are tuned as close to exact unison as possible.
A general tuning procedure is described in the Troubleshooting Section beginning on page 53.
THE INCREMENTAL CONTROL
The incremental control is the most important single control on The Source. It controls the settings of all variable
parameters, and determines the rate of operation for most Level 2 functions. Its operation should be thoroughly
understood.
The incrementer is a freely-turning opto-electronic controller. An optical sensor notes a change from light to dark,
which is generated by passing spaced bars through the sensor (as shown in the figure below). There are 120 opaque
bars on the transparent incrementer, allowing 240 changes of status.
(LIGHT SOURCE/
LIGHT SENSOR MECHANISM)
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