An as accurate sounding as possible Zoia patch to replicate the famous Fairfield Circuitry pedal Shallow Water, but with added perks, such as 2 different stereo effects and much more. Enjoy it.
Controls for the Zoia mono patch (stereo compatible) “Acqua Bassa St”
From top left in the figure above:
RATE:
This is simply the frequency of square pulses separated by random time intervals. The frequency of “randomness” can be adjusted with this knob. The pulses change the pitch of the incoming audio signal (basically a vibrato effect, but random, not like a regular sine wave vibrato), similar to what would happen in an audio tape machine. From Fairfield Circuitry manual: The RATE control adjusts the time intervals at which the random pitch fluctuations occur.
DAMP:
This is basically a smoother for the random square shaped pulses. If you turn the knob clockwise, the shape move from hard square pulses to a gentle randomish curve and consequently a less aggressive change in pitch. CCW is perfect for a tape wow and flutter effect, CW it’s better for chorus when the MIX is at 12 and it’s better with high DEPTH values. From Fairfield Circuitry manual: The DAMP control affects the slope of the modulating signal. At its minimum, the pitch modulations are quick and sudden; the random changes in modulation voltage are almost instantaneous. Increasing DAMP will elongate and soften the modulation. At high DAMP settings, the changes become so slow that they are not heard as pitch modulations. To hear the changes, some dry mix needs to be applied.
DEPTH:
As simple as it sounds, it applies more or less of the effect, but for the pitch modulation only, not the low pass filter. From Fairfield Circuitry manual (three mod controls is referring to rate, dump and LPG): The DEPTH knob adjusts the intensity of the modulation. The interaction between all three modulation controls is noticeable. The range of modulation is focused towards subtle variations. Adjust to taste, though less is more.
MIX:
Since the beginning of pedal effects history, people know that if you mix your pitch modulated effect, also known as vibrato with a dry signal, voila’, you get a chorus effect, and that’s exactly what you get here. If you smooth the square wave with DUMP, adjust the frequency and filter sweep (LPG), the MIX, DEPTH etc., yes, you get a chorus effect, but quite different from the classic one from the 80s (which I personally dislike), it’s more subtle and organic. If you don’t want any chorus at all, then the MIX goes all the way clockwise. From Fairfield Circuitry manual: The MIX control balances between the dry and wet signal. When it’s full wet (clockwise) the effect is like a vibrato. Chorus-type sounds are achieved by adding some of the dry signal (counterclockwise).
VOL:
This one is self explanatory. It’s very useful when the LPG is at lower levels, to compensate for the loss of volume. From Fairfield Circuitry manual: The VOLUME knob controls the output volume. Unity is around noon and beers around 5 at my place.
From top right in the figure above:
LPG:
This knob, essentially, adjusts how sensitive is the sweep of the low pass filter (how much it opens) to the strength of the incoming audio. Fully CW, with a light touch of the guitar/synth the filter opens up nearly fully but not quite. Fully CCW, even by playing hard the filter opens up very little and all the high frequencies are absent. From Fairfield Circuitry manual: The LPG control adjusts the level of the envelope going to the low pass filter and gate circuit. At lower counterclockwise the signal will be darker, choke subtle notes and reduce sustain. At higher settings, the sound will be brighter, have more sustain and might reveal some noise produced by the bucket brigade device. That’s the annoying noise part I hate! I love the past noon clockwise LPG, but I hate the on and off noise.
LPG Cutoff (trim pot):
This is not an extra adjustment, it’s just readily accessible in ZOIA. This one, essentially, changes the frequency of the filter “at rest” when there is no audio coming. With audio coming in, the filter will start to open up from the frequency adjusted here (cutoff frequency). The manual explains it beautifully. From Fairfield Circuitry manual: The recovery filter’s lowest frequency can be adjusted, to fine tune the way it will react to incoming signals. Lowering this frequency emphasises the action of the low pass filter, effectively raising the threshold of sensitivity.
LPG Sweep Speed:
This one is really an extra control. Turn it fully CCW to have a very fast sweep of the low pass filter, without “wah wah” effect. Turn it CW and you get a slower sweep speed that accentuates more the wah wah effect, adjust to taste. You can also visualise the speed of the sweep by looking at the 4 bottom central LED indicators.
Reverb:
It’s ZOIA, why not! It’s the Reverb Lite. I used the light one because the more complex reverbs max out the CPU in older versions of ZOIA (3.0, 3.2 etc.), with firmware 5.0 more complex reverbs can be used without maxing out the CPU though. If you want to adjust it to suit your taste, you can find it at page 1 (the peach/white row in the I/O page).
From top centre in the figure above:
LPG Sweep Depth/Speed Indicators (3 bottom right red LEDs)
These indicators show you the speed and the range of the low pass filter sweep controlled by the attack of your instrument.
Controls for the Zoia true stereo patch “Acqua Bassa St” The stereo section
You have two completely different stereo effect choices here, choice 1 at the top (2 control buttons and 2 LED indicators in the rectangle in the figure): I call it “Stereo Panner effect choice 1”, and it does exactly that, with a little twist though, the pan is random and you can adjust the spread from mono to crazy separation, and you can also adjust the rate of the “randomness”.
The stereo choice 2 I call it “Stereo L-R Dual choice 2” (little rectangle in the figure). Switch it on to simulate two Shallow Water pedals, one on the left channel and one on the right channel. This creates a very nice stereo (random) effect with a somewhat accentuated chorusish effect. The stereo effect is active only for the pitch change, not for the low pass filter though (the filter is common for the “2 pedals”). When off the Acqua Bassa St is a normal true stereo effect, that passes whatever stereo effect is at the input of Zoia.
From top centre in the figure above:
Stereo choice 1
Stereo Spread:
This control does exactly what it says on the tin, adjust to have a wider or narrower stereo spread. Fully CCW stops the stereo effect.
Random Pan Rate:
This control adjusts the frequency of the random left/right pan movement. Turn it CW to get a faster random left/right effect. Both the dry and wet signals are panned in sync, to get a stereo effect and still preserving the Shallow Water fragile/stutter sensation, without chorusing effect.
L-R Pan indicators:
These 2 LEDs give you some feedback on how fast and how randomly the pan is going.
Stereo choice 2
Stereo L-R Dual on/off:
A simple on/off switch to engage the “Stereo L-R Dual choice 2” effect
RATE/DUMP indicators (2 right bottom blue LEDs):
These indicators show you the frequency of the random pulses and how smooth or sharp they are (adjusting the DUMP control). If this stereo choice 2 is activated, these two indicators will show you that.
I don’t like to activate the two choices at the same time, to me, they don’t sound good together, but feel free to experiment. Choice 2 has a larger separation than choice 1, nice if heard through speakers, but not so much through headphones.

See attached a pdf with all the details of both the mono and stereo patches, including some block diagrams.
Attachment Zoia-Acqua-Bassa-project-69d5fa93266f0.zip