Synthesizers.com Q150 Quick Start Manual

Q150/Q150A Transistor Ladder Filter
Based on Bob Moog's famous design, the Q150 Transistor Ladder Filter
changes the harmonic content of signals to create new, interesting sounds
which is the basis of subtractive synthesis. The cutoff frequency can be
controlled manually and/or controlled by another signal such as an enve-
lope generator, oscillator, keyboard, etc. Frequency control signals can be
attenuated and inverted. Resonance (Q) of the filter is adjusted with a pan-
el control. Both -12dB and -24dB slopes are available.
In most ladder filters the output signal is greatly reduced as the resonance
is increased. This usually requires resetting input levels (sometimes many)
when changing resonance settings - quite annoying. Special circuitry in the
Q150 keeps the output signal level at various resonance settings while
keeping the harmonic content unchanged. This option can be disabled with
a jumper if desired.
The Q150A is a single-wide version with only one attenuated input and
one frequency voltage control. The frequency voltage control can be
changed from reversable to attenuated by moving the pot and jack con-
nectors on the pcb.
Specifications
Q150 Panel Size: Dual width 4.25"w x 8.75"h.
Q150A Panel Size: Single width, 2.125"w x 8.75"h
Low Pass Slope: -12dB/Oct or -24dB/Octave.
Cutoff Frequency: 1/V per Octave and adjustable.
Resonance (Q): 1 to self-oscillation.
Frequency Range: 20hz to 20khz.
Power: +15V@30ma, -15V@30ma.
Waveform Levels: 10V PP.
Dec 2018