user manual
24
TECHNICAL INFORMATION
This section contains technically-oriented information which is somewhat more
detailed than the previous sections . Some users will find this information helpful in
devising advanced uses for the CP251. The information is arranged according to the
CP251 module to which it applies.
MIXER
The nominal input resistance of inputs #1 and #2 is 50KW. The nominal input resistance
of inputs #3 and #4 is 100KW. The nominal output (source) resistance of each of the
outputs is 500 W.
The maximum input-to-ouput gain is unity. The maximum nominal output voltage range
is ±5 volts. The - output is the negative of the + output.
The frequency response of the mixer is DC to 50kHz.
The OFFSET knob can be considered a fifth input with a voltage range of ± 5 volts.
LAG
The nominal input resistance is 10 megW. The nominal output (source) resistance is
500 W.
The nominal input-to-output voltage gain is unity.
Time constants of rising and falling waveform edges are determined by the RISE and
FALL knobs. Nominal time constants are 1 millisecond, 100 milliseconds, and 1 second
when the knobs are fully counterclockwise, in midposition, and fully clockwise,
respectively.
LFO
The nominal input resistance of the PEDAL IN jack is 120 kW. The nominal voltage-to-
frequency characteristic of this input is: a one-volt increase doubles the frequency.
The operating frequency of the LFO is determined by the sum of the voltage at the
PEDAL IN jack and the voltage coming from the RATE control. An expression pedal such
as the moogerfooger EP-1 has a nominal range of 0 to +5 volts when plugged into the
PEDAL IN jack. You should use the RATE control to set the minimum desired LFO
frequency, and adjust the voltage range of the pedal or externally-applied control
voltage to get the desired range of LFO frequencies.
The LFO frequency can go both lower than the minimum calibration on the RATE
control (by applying a negative control voltage), and higher than the maximum
calibration on the RATE control (by applying the appropriate positive control voltage).
The minimum frequency is less than 0.03 Hz (one cycle every 33 seconds), and the