At the heart of PRALINES, there’s a special filter which consists of 4 band-pass filters running in parallel.
Each filter frequency can be controlled independently. (FREQ) Resonance however, is a global parameter for all 4 of the filters. (PEAK)
Filters can be blended with the dry signal. (MIX)
Modulation applied to filters frequency can be either envelope, LFO or expression pedal. (MOD)
The LFO speed can be controlled by envelope or expression pedal. (LFO CTRL)
A gated FUZZ helps add to the synth-like experience.
As said before, there is 4 parallel band-pass filters. It’s comparable to a double EHX Bass-Balls (which is 2 band-pass filters in parallel), or a quarter of a vocoder (which is 16 band-pass filters in parallel). It could also be referred to as a formant filter.
The frequency range of the filters goes from sub-bass up to mid-treble; They were specifically designed not to oscillate at high frequencies preventing possible damage to your ears or speakers.
The PEAK knob controls the global resonance of this formant filter. When fully CCW, the sound is soft/flat and it will act as a 4 band parametric equalizer. Mixed with out-of-phase dry signal, phase cancellation occurs and it’s capable of producing phaser/vibrato sounds. As you increase the PEAK value, you increase the resonance of each band-pass filter and less phase cancelation occurs.
When fully CW, filters self-oscillation occurs and you now have 4 controllable sine-wave VCO’s. You can even make nice chords!
The FILTERS knob is controlling the level of the filters, it’s useful if you want to tame things in some situations.
The MIX knob is used to blend the dry signal with the filtered signal. Fully CCW is dry only and fully CW is filters only.
How to proceed with those 3 Knobs? (PEAK, FILTERS, MIX)
Set MIX knob fully CW, choose a PEAK value. (flat, colored or near self-oscillation), adjust FILTERS so that gain is consistent with your bypassed level, and use the MIX knob to blend it with your dry signal.
There are 4 small FREQ knobs, they set the base frequency of each filter.
The base frequency will then be modulated according to the 4 small MOD knobs.
The 4 FREQ knobs should not all be set to the exact same position. This would result in unwanted self-oscillation, even with PEAK fully CCW.
Most of the time, what you’ll want is 4 different base frequencies for your filters.
MOD rotary switch selects which modulation is applied to filters: envelope down, envelope up, LFO, expression pedal. In addition, it shifts the frequency range of each FREQ knob up or down:
envelope down = higher frequencies.
envelope up = lower frequencies.
LFO or expression pedal = mid frequencies.
SENS sets the sensitivity of the envelope generator.
Settings will vary according to your playing dynamics, your instrument (guitar/bass) or pickups (single coil/humbucker).
This envelope generator is followed by a slew
limiter that will slow/smooth the envelope:
ATTACK slows down the attacks
DECAY slows down the decay
When increasing ATTACK, you may need to increase SENS
This is a simple triangle LFO with two frequency ranges: SLOW and FAST.
LFO frequency is set by the small SPEED knob.
The corresponding LED will blink in relation to the speed.
BONUS FEATURE: when the switch is on FAST position, LFO will be acting on other modulations (envelope down, envelope up, expression pedal).
EG: if MOD selector is on envelope up and LFO switch is on FAST, the resulting modulation will be an envelope modulated by a LFO. (can be better heard with slower envelopes)
With the LFO CTRL rotary switch, the LFO rate can be controlled by: (from left to right)
none, envelope down, envelope up, expression pedal.
In this case, the SPEED knob will set the slowest rate. (don’t put it fully CW, you wouldn’t notice any speed modulation)
It’s a basic PNP transistor gated fuzz.
It’s placed just before the filters input, switching it on has no affect on SENS or on the dry sound.
The FUZZ switch turns it on or bypasses it.
The FUZZ knob changes the fuzz texture from soft saturation (fully CCW) to hard squared fuzz (fully CW).
The gate starts to engage around 12 o’clock. You’ll be able to hear the noise floor disappearing.
You can control the filters frequencies or LFO rate with external hardware.
If using a classic/passive expression pedal, use a TRS stereo jack.
If you use CV signal (0-5V), then use a TRS stereo jack with RING detached. (it would temporarily work with a mono jack, but for some reason it’s better to use the cable described above)