Moisturizer Modifications

WARNING - I take NO responsibility if you blow up your moisturizer, you aren't gonna die trying but if you're not careful you could potentially blow shit up (i.e. break your Ekdahl Moisturizer). That being said, these modifications should be really easy to do and they have been designed to be as non-intrusive as possible, no modifications of the actual circuit board is necessary. Even a beginner should be able to do this if following the instructions carefully, for someone with soldering and circuit experience, not even the mods marked "hard" should be hard at all.

If you feel that these instructions are violently unclear, please contact me at .

All of these mods will require a soldering iron, some snippers, stranded wire (26 gauge or close), a power drill (hand or press, either way), wire stripper, (or sharp teeth, worked for me for years) some kind of solder-sucking device, very fine tweezers, lead free solder, tape (painters tape is good), pliers & a shitload of patience.

The modifications listed herein are examplified on a revision 4 circuit board, if you have any other circuit board revision and can't figure out how to do these mods, please contact me.

Most of these modifications are "scientific", as in they have been planned with a certain outcome in mind. Some of the mods however are more of a circuit-bent nature, which i have stumbled upon by accident. All of the part references here are to Mouser & Small Bear Electronics, this because i find them to be serious and reliable companies that i myself use for original parts for The Ekdahl Moisturizer.

Good praxis for the novice:

To get best results as a beginner, be PATIENT and don't use the shittiest tools you can find because your results will be poor, a tool that costs you $3 might last you 1 year while a $20 one might last you a lifetime. Radioshack soldering irons are total shit but can be used if you only ever want to modify this one thing and isn't the least interested in modifying or repairing anything else (i STRONGLY suggest buying a decent but cheap iron like the WES-51). Never heat up an area for more then 5 seconds (hard with the RS irons as they work so badly), if using a temperature-regulated iron set it to 350C / 650F except for when soldering switches, then go down to 250C / 500F (since they like to melt inside). Always keep your tip clean and tinned. I only use lead free solder and i suggest you do the same. When it comes to drilling i suggest marking the hole position with a centre punch as it will automatically guide the drill in the right direction, and always always use a small drill first and build up to larger holes.

Avaliable mods:
  1. Filter-Reverb chain switcheroo (add a switch to put the filter in front of the reverb instead of vice verca)
  2. More resonance bubble
  3. Resonance limiter (less resonance bubble)
  4. Input gain overdrive
  5. Internal feedback
  6. LFO speed modifications
Check out the video


Modified (all mods not shown)
Download high-res version here

1. Filter-Reverb chain switcheroo

This modification will add a switch that enables you to put the filter in front of the reverb instead of reverb-first, if you mainly use your Ekdahl Moisturizer by putting sound through it rather then using the springs to generate sound, i'd say this is an essential mod.

Dificulty: Hard
Time required: 20-40 minutes
Parts needed: Enclosure mods: 1 hole for the switch

Start by taking the wire and cut it in 6 equal parts - i suggest roughly 15cm per wire (5.9"). We'll also need three really short wires - about 2.5cm each (about 1"), and two 5cm wires (2").

Remove the 3 resistor networks RN10, RN21 and RN19 marked in the picture of the original circuit board, remove any solder from the holes (the resistor networks might not have the same exact color or shape as in the picture).

Position RN19

Position RN10

Position RN21
Now take six of the 100K resistors and bend one leg down along side the body so the two legs are in parallel. In position of RN19, place on resistor on holes 1-2 and one in holes 5-6, place a unbent resistor in hole 4 - the square top hole is hole number 1. Take one of the 15cm wires and place it in hole 3.

In position of RN21, place bent resistors in 1-2, 3-4, 7-8, 9-10 and a unbent resistor in 5.

Now take four of the 27K resistors and bend them the same way we did with the 100K, in position RN10 place them in holes 1-2, 3-4, 7-8, 9-10 and place a unbent in hole number 6. Place a 15cm wire in hole number 5.

To avoid for the resistors to accidentally short to the enclosure, we need to bend them to the sides before soldering. Naturally, you need to make sure you do not bend them down so that the metal part touches - and shorts - any other components metal parts. To be able to flip the board and solder without all of the resistors falling out, i recommend taping the components down to the board. Flip the board and solder, cut the parts of the resistors that sticks out underneath.

Cut the top of the three resistors that only have one leg soldered in so that about 0.5-1cm sticks out. Take one of the 5cm wires and solder it to the resistor you just cut in position RN19 hole 4. Take the other 5cm wire and solder it to the free leg of the resistor placed in position RN21 hole 5, now take a 15cm wire and twine it together with the loose end of the last wire you soldered. Solder the two wires to the cut resistor in position RN10 hole 6.

Now for the trickiest part; we need to desolder leg 5 of U1, and leg 3 of U18. The safest methode of doing this might be to simply desolder the entire two ICs, bend the two legs upwards, and solder the ICs back in. Me i was lazy and did what i felt to be easiest; take your tweezers and place them so that you can *carefully* bend out the leg that you need desoldered while heating it up from underneath - this might be easier if you add some solder to the back first. If you bend too hard or don't have enough heat, you can damage the component - or much worse - the circuit board. An easier methode of doing this can be to simply cut all the legs on the two components, desolder the legs one by one, and take a new component of the same sort (U1 = TL074 or TL084, U18 = TL072 or TL082), bend the legs and solder the new components in.

Now take the 5cm wire you soldered to the resistor in position RN19 hole 4 and twine it together with one of the 15cm wires, solder both wires together to leg 5 of U1 that you just desoldered. Take two 15cm wires and put one in position U18 hole 3, flip and solder. Take the next wire and solder it to LEG number 3 of U18.

If you have done everything right, you should now have 6 x 15cm wires sticking out of your board - these are getting wired to the switch. Start by twining together one of the 2.5cm wires to the unsoldered end of the wire soldered to U1 leg 5, twine another wire together with the unsoldered end of the wire soldered to U18 leg 3, and twine one to the unsoldered end of the wire soldered to the resistor in RN10 hole 6. To make sure the twining doesn't come undone when soldering these to the switch in the next step, i recommend soldering them together first.

3PDT Switch
To wire up the switch, solder the pointed out wires to the following positions.
  1. Wire from U1 leg 5
  2. Wire from resistor in RN10 hole 6
  3. Wire from U18 leg 3
  4. Wire from RN19 hole 3
  5. Wire from RN10 hole 5
  6. Wire from U18 hole 3
  7. 2.5cm wire from switch position 2
  8. 2.5cm wire from switch position 3
  9. 2.5cm wire from switch position 1
All you've gotta do now is drill a hole in the enclosure for the switch - i highly recommend trying it out first though so you know that it works!

2. More filter bubble

This modification will add a switch that gives more resonance "bubble" by overdriving one of the stages in the filter.

Dificulty: Easy
Time required: 5 minutes
Parts needed: Enclosure mods: 1 hole for the switch

RN10 & U4

DPDT switch
Cut two 15cm (6") wires. The two points in the picture marks where to solder these wires, however i suggest soldering these to the underside of the board (it's just easier to show where to do this on the upper side).

Solder the other two ends of the wires to the switches position 1 and 3.

3. Resonance limiter

Two 1N4148 diodes
This modification will remove the resonance "bubble", whether this sounds boring or not it's useful in conjunction with other mods - especially the feedback mod.

Dificulty: Easy
Time required: 5 minutes
Parts needed:

Enclosure mods: 1 hole for the switch


DPDT switch
Cut two 15cm (6") wires. The two points on RV8 marks where the two wires are to be soldered, again i suggest doing the actual soldering on the underside of the board.

Now take the two 1N4148 diodes - if you look closely, there should be a black line around the body on one end, twine the diodes together so that the lines point in DIFFERENT directions.

On the switch, solder one of the wires (doesn't matter which), to position 1, solder one end of the two twined diodes to position 3 and last, solder the second wire to the part of the twined diodes that is yet to be soldered. Now take the two wires coming from teh switch and solder them to the two tabs of the resonance potentiometer that are on the extreme left and right (doesn't matter which wire goes to which tab).

4. Input overdrive

This mod will add more gain to your input stage, you might or might not want to make this a switch because with the added gain it can be hard to dial in non-distorted volume with high gain output instruments. Also it allows you to flick in distortion while playing :)

Dificulty: Easy
Time required: 5 minutes
Parts needed: Enclosure mods: 1 hole for the switch (optional)


DPDT switch
The original input stage of the Ekdahl Moisturizer allows for 10 times gain (Rev. 3 & 4, if you're one of the 9 people who has a Rev. 1 or 2 you don't need this mod.).

By replacing R5 - which is a 10K resistor - with a 1K resistor you can get up to 100 times of (theoretical) gain, lower values gives even more gain. Be careful with choosing a too low value as it will be very hard to dial in the volume otherwise.

If you do not want to have the extra gain switchable, simply remove R5 and replace it with the 1K resistor.

If you want it switchable, solder two 15cm wires to the two solder-points of R5 on the underside of the board and solder one of the wires other end to the switches terminal 1. Solder the 1K resistor to the other wire and solder the unsoldered end of the resistor to the switches terminal 3.

5. Internal feedback


If you like creating noise-hell, this mod is an absolute must!! It makes the moisturizer SQUEAL.

Dificulty: Medium
Time required: 10 minutes
Parts needed: Enclosure mods: 1 hole for the potentiometer


Cut three 15cm (6") wires, solder one of them to the P5 hole 3 (the right-most one), take the second wire and solder it to the point marked on C22.

Take the two 20K resistors and twine them together in one end as marked in the picture and cut so that it's roughly 1cm (0.5") sticking out and solder them together. Cut the other end of the resistors to the same length.

Now desolder the wire coming from the jack-board that's in P5 hole 4 (the left-most one) and solder in the twined end of the two resistors in it's place. Take the wire you just desoldered and solder it to the free end of one of the twined resistors, take the last 15cm wire you cut and solder it to the other free resistor.

Before soldering the potentiometer, take some pliers and break of the tab marked, depending on where you are going to place the potentiometer you might also have to bend the terminals so that it fits in the enclosure. Solder the potentiometer as follows:
  1. Wire from P5 hole 3 (right-most hole)
  2. Wire from the resistor in P5
  3. Wire from C22

6. LFO speed modification

This mod allows you to change the maximum and minimum speed of the LFO.

Dificulty: Easy / Medium
Time required: 10 minutes
Parts needed: Enclosure mods: 1 hole for the switch (optional)


DPDT switch
There's a bunch of ways of doing this mod, but simply put there's a capacitor - c1 - that sets the minimum and maximum LFO speed, by changing this capacitor from it's original 2.2uF value to a higher value, you get a slower max and min LFO speed, changing it to a lower value capacitor will make the min and max speeds be faster. The faster speeds can generate very interesting artefacts in the sound when modulating for instance the filter cutoff. Make sure to use BIPOLAR polyester or polystyrene capacitors, electrolytics (the ones with + or - signs) are no good.

To indefintely change the LFO speed, simply change out c1 to a different value. I suggest however adding a three-way switch instead to be able to have really slow, normal and really fast speeds. This is how you do that:

Desolder c1 - don't throw it away -, and replace it with a 1nF capacitor (for really high speeds, this will create nice artefacts and if you don't like that perhaps go with a 10nF or even 100nF cap). Now solder two 15cm (6") wires to the ends of the capacitor, take one of the ends and solder it to terminal 3 of the switch. Take the 2.2uF cap you desoldered and solder one leg to terminal 1 of the switch, take the 10uF capacitor (for slow speeds, higher farrad caps will go even slower but tend to be huge and expensive) and solder one leg to terminal 5. Now take the free legs of the two capacitors and solder them together with eachother and the second wire from the capacitor on the circuit board.

Video of the modifications listed