The Knas Ekdahl Moisturizer 2 is a spring reverb, an analog multimode filter and an LFO in one unit, and its defining feature is that the spring tank sits exposed on the outside of the enclosure. As Knas puts it, "the Ekdahl Moisturizer is a spring reverb where the springs are exposed so they can be played/hit/fiddled wit[h]", so the player can use it as an instrument as well as an effects unit1. The tank is fastened to the main unit with self-adhesive velcro and detaches for transport, and it ships in a hard cardboard tube for protection12.
The filter is a state variable type with no resonance limiter, which shapes its character. Knas describes it as abrasive, saying it "can sound really bubbly and metallic, way more than any filter the maker has heard, but also completely normal depending on resonance and/or gain"1. The unit was developed with the help of Jason Willett (Half Japanese, Leperchaun Catering), Martin Schmidt (Matmos, Instant Coffee) and Joshua Atkins (Polygons, Major Powers), among others1.
The controls
The Moisturizer 2 divides its front panel between the LFO, the filter and two wet/dry crossfaders. Almost everything is reachable by knob, by control voltage or by expression pedal, and the filter cutoff can also be swept by the internal LFO1.
| Control | What it does | How it can be controlled |
|---|---|---|
| LFO Speed | Sets the speed of the internal LFO | Knob and CV/expression pedal1 |
| Square / Triangle crossover | Shapes the LFO waveform between square and triangle | Front panel1 |
| Cutoff | Sets the filter's cutoff frequency | Knob, CV/expression pedal and LFO1 |
| Resonance | Sets filter resonance, with no resonance limiter | Knob1 |
| Filter / No filter | Wet/dry crossfader for the filter | Knob and CV/expression pedal1 |
| Reverb / Preamp | Wet/dry crossfader for the reverb against the preamp | Knob and CV/expression pedal1 |
The back panel carries CV and expression pedal inputs for Reverb Mixture, VCF Cutoff, VCF Filter Mode (lowpass, bandpass or highpass), Filter Mixture and LFO Speed1. The preamp section is designed for a maximum of 10 times gain, which Knas says is there to accommodate low level output instruments such as guitars, so a guitar can drive the unit directly1.
Player Jason Glover runs one on his pedalboard. In a Strymon rig feature he explained its role: "Since it runs after all of the dirt, I use it to sculpt my overall sound before things start running in stereo," and he tweaks the Frequency Cut Off and Resonance to thicken everything up4.
Power and the detachable spring tank
The Moisturizer 2 uses an external wall-wart supply. Knas would have preferred an internal supply, but abandoned the idea because of mains liability and the differences between countries' mains systems1. From revision 4 onward, the power input accepts either AC or DC supplies of any polarity through a standard 2.1mm barrel connector. The unit requires a minimum of 12V and can theoretically handle DC up to 20V (18V maximum for AC), though Knas recommends not going above 15V DC or 12V AC in practice2.
Revisions R3 and earlier are different: they require an AC supply at 12V at 0.33A AC, which Knas says are unfortunately not that easy to find. A DC output supply will not work in those older units, and an AC supply has no polarity to worry about5.
The spring tank connects to the rest of the unit and is held on with self-adhesive velcro, so it can be pulled off and packed in its hard cardboard tube when you travel12. In the box you get the Moisturizer itself, the detachable spring reverb tank in its tube, and an optional American power supply (12 VAC 500mA, 2.1mm plug)26.
Moisturizer versions and mods
The Moisturizer has gone through several hardware revisions, and the line between old and new matters both for power and for modification. R3 and earlier units are through-hole construction; R4 and later are surface mount, and the R4 board breaks all the mod points out as a single header, which makes the mods far easier to reach78. The mods themselves are the same across revisions, with the R4 page referring back to the R3 instructions8.
Knas publishes six documented modifications for the earlier units7:
- Filter-Reverb chain switcheroo (Hard): a 3PDT switch that puts the filter in front of the reverb instead of after it.
- More filter bubble (Easy): a DPDT switch that adds more resonance "bubble" by overdriving one of the stages in the filter.
- Resonance limiter (Easy): two 1N4148 diodes wired to RV8 and the resonance potentiometer's outer tabs, taming the unlimited resonance.
- Input overdrive (Easy): replacing the 10K resistor R5 with a 1K resistor for up to 100 times theoretical gain, optionally switchable for flicking in distortion while playing. Rev. 1 and 2 owners already have this and do not need the mod.
- Internal feedback (Medium): a potentiometer and two 20K resistors for feedback within the unit.
- LFO speed modification (Easy/Medium): changing capacitor C1 from its original 2.2uF value to change the LFO's minimum and maximum speed, with a three-way switch for selecting ranges.
The mods are designed to be non-intrusive, with no circuit board modification necessary, and Knas calls them beginner-friendly if the instructions are followed carefully. They do require drilling enclosure holes for switches and pots, a soldering iron (Knas suggests a Hakko fx-888d or Weller WES-51), and the usual hand tools. For the LFO mod, the capacitors must be bipolar polyester or polystyrene types; electrolytics will not work. Knas takes no responsibility for units damaged during modification78.
If you are comparing, the earlier Knas Ekdahl Moisturizer covers the same ground in its R3 and earlier form, including the harder-to-find AC power requirement23.
Videos
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Questions
Is the Knas Ekdahl Moisturizer 2 mono or stereo?
It is a mono unit. Knas states this plainly on the product page, and it applies to the earlier Ekdahl Moisturizer as well. If you want stereo wet effects you would need to run it alongside other gear, as player Jason Glover does, using it to sculpt his sound before his signal splits into stereo.
Can I plug a guitar straight into the Moisturizer 2?
Yes. The preamp section is designed for a maximum of 10 times gain, which Knas says is there to accommodate low level output instruments such as guitars. The preamp sits on a wet/dry crossfader with the reverb, so you can blend how much of it you hear.
Does the Moisturizer 2 have a built-in power supply?
No. Knas wanted to build in an internal supply and skip the wall wart, but abandoned that because of mains liability and differences between countries. It runs from an external supply through a standard 2.1mm barrel connector, and from revision 4 onward the input accepts AC or DC of any polarity, needing a minimum of 12V.
What is the difference between the older and newer Moisturizers?
The big difference is power. Revisions R3 and earlier require an AC supply at 12V at 0.33A AC, which Knas says are not that easy to find. Revision 4 and later accept AC or DC of any polarity through a standard 2.1mm barrel connector, so common supplies work. Revision 4 also moved to surface mount construction and breaks all the mod points out as one header on the board.
Can the filter be controlled with an expression pedal?
Yes. The back panel has CV or expression pedal inputs for Reverb Mixture, VCF Cutoff, VCF Filter Mode (lowpass, bandpass or highpass), Filter Mixture and LFO Speed. The cutoff is controllable by knob, expression pedal and the internal LFO, and both wet/dry crossfaders are knob and expression pedal controllable.
