Operating Instructions
INPUT LEVEL
The input level should be set so that the peak LED never lights continuously. The brighter the
LED shines the more you are overdriving the unit and this is generally to be avoided. Ideally,
the peak LED should never come on in normal operation. Once the input level is set to the
correct point then the output level control can be adjusted to suit.
PEAK LED
This gives a visual indication of when the signal being sent to the delay line circuitry exceeds
the recommended amount. As soon as the LED starts to glow the delay line circuitry will be
close to clipping and distorting. The level required to clip the delay lines varies with frequency
and the harmonic content of the signal. Brighter sounds, or ones of very high pitch, are more
likely to clip than low frequencies. For example; a static sine wave at 200Hz will clip at 3.6V
peak-peak. While at 2kHz clipping will start at 1.2V peak to peak.
TRIANGLE RATE
Controls the rate of the triangle wave low frequency oscillator (LFO). An LFO produces an
output signal that changes in voltage with a repeatable and periodic shape. The triangle wave
output rises at a constant rate, reaches an apex and then descends at the same rate as it went
up. Then at its lowest point it rises again and the process repeats itself. It is called a triangle
wave because when viewed on an oscilloscope the trace is made from a series of triangles.
TRIANGLE DEPTH
Controls the depth of the triangle wave modulation. The deeper the modulation the greater the
change in delay times the BBD lines exhibit. Quick changes in delay are heard as a change in
pitch by the listener. With a triangle wave the pitch changes can be quite severe as the
waveform changes direction.
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