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Slim Phatty User’s Manual - The Basics
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Slim Phatty User’s Manual - The Basics
To understand the operation of the Slim Phatty, refer to the diagram below. The diagram shows the flow of
the audio, control voltage and modulation signals in the Slim Phatty. Heavy lines are used to indicate audio
signals, which flow from left to right. Lighter lines indicate the control voltages (CV’s), which flow from the
top and bottom. Dotted lines indicate programmable modulation routings.
As the diagram shows, the SP’s source signals are created by two voltage-controlled oscillators which are
mixed together along with the external audio input. The combined audio signal is passed to the low-pass
filter, where the tone is sculpted according to the settings of the filter parameters and the Filter ADSR enve-
lope. The signal then passes to the amplifier stage, where the Volume ADSR envelope shapes it. Finally, the
signal is routed to the output section, where the final level is set by the Master Volume control.
For many users, MIDI will be the main source of control for the Slim Phatty. Each time the SP receives a
MIDI ‘Note On’ command, the SP produces a Pitch CV and Gate signal in response. The Pitch CV signal is
used to specify the pitch of the oscillators, while the Gate signal is used to simultaneously trigger the Filter
and Volume Envelope Generators.
The SP can also be operated via CV and Gate trigger connections, providing for a more ‘old school’ method
of control.
Signal Flow
