Showing posts with label Filter. Show all posts
Showing posts with label Filter. Show all posts

Saturday, 22 November 2025

Jürgen Haible Wasp CV Filter LM13700 version

 Chris Stelloh have been playing around with Jürgen Haible Wasp CV Filter and sent me two verified layouts..

In hi sown words:

 I had a chance to build up that LM13700 version of the Wasp Filter and found that using a much different value of potentiometer for the cutoff control made for a better filter sweep.

This one is also verified. It contains a level pot that cuts or boosts the CV level. The oscillation switch implements the modifications that people have come up with for the Doepfer A-124 - which is a module that is basically a wasp. Albeit with some minor part value changes, as well as a HEAVILY modified CV and frequency/cutoff section.


 

 

Thursday, 30 November 2023

Electro Harmonix The Worm / Madbean Charlatan

 A vintage big box The Worm with some useful improvemnts and mods by Madbean. The power section have been reworked by a voltage doubler and a voltage regulator for 9v to 15v operation. An internal volume trimpot is added. And the unknown original vactrols is replaced by a trio of LDR/LED pair.

Schematic and more information is avaiable HERE.


 


Sunday, 23 July 2023

Electro Harmonix Doctor Q - Vintage

 Layout based on the old version from the 70s. Note that this one is really picky about op amp selection so be prepared for some socketing...



Monday, 17 July 2023

F'Deck / Broughton Hybrid HPF

 Another guest appearance by Sebastian who generously shares his interesting designs!

Here is a snippet of his description for it:

...hybrid of the F'Deck (series 3) and the Broughton high-pass filters. I wanted the steeper slope of the F'Deck (24db/octave below 35Hz) with the gain boost of the Broughton—so, here it is!

 

 

 

 

Saturday, 10 June 2023

Madbean Headtrip 2

Once again, a guest appearance. Chris at CDC was brave enough to dabbling with some Spin FV-1 processors. Yes, these are SMD parts there is several vendors online that sell adapter boards.

 This one is VERIFIED.

 

Since I started building effects in 2020, there has been a "level up" step I've been avoiding. As the level digital signal processing that is available through industry standard effect makers like TC Electronic, Boss, Line 6 and Strymon filters down to the DIY/hobbyist level - there really is no excuse for not at least TRYING digital signal processing.

The most commonly available engine of these DSP effects is the Spin FV-1 reverb processor. They are about $10-$15 each and have 28 tiny little surface mount legs that need to be soldered to tiny little pads on the circuit board without any bridging. So I've been squeamish and avoided them. Until now (dun dun).

After about 3 years of doing this I felt like my dexterity and soldering iron proficiency had progressed to the point where I shouldn't put this off any longer. I also MUST thank DK pedals for their tutorial that was a serious confidence builder.

This effect contains that chip - soldered to an adapter board designed by MAS Effects, which is attached to my stripboard layout of the Madbean Headtrip 2 FV-1 project. It also contains the algorithm chip from that project featuring the presets designed by Brian of Madbean..

The 5 knobs are for dry and effect level, as well as three parameters that change with each effect preset. There's a lot to cover with this pedal, which is why my video is about 5 times longer than anything I've posted so far... if you make it through all 8 clips, I salute you!!!

Mode 1: Choir - similar to the EQD organizer, with the controls condensed to three knobs: octave down, octave up, and choir (which has a slight delay on the signal)

Mode 2: Filter+Octave - an envelope follower that is controlled by knobs 1&2, with an octave up and down dialed in by knob 3.

Mode 3: Detune+Tremolo - this is similar to the "detune" mode on the Whammy pedal. Its's a faux chorus of sorts. Knobs 2&3 control the speed and depth of the tremolo

Mode 4: Flangecho - an 850ms delay. Length and repeats are knobs 1&2, flanging level in the repeats is knob 3.

Mode 5: Echo+??? - a 975ms delay. Knobs 1&2 are the same as mode 4. Knob 3 controls a multi effect that goes from modulation to buzzy ring modulation to tremolo in the repeats.

Mode 6: Flangeverb - knob 1 is the reverb level, knob 2 is the low cut, knob three blends in a similar flange modulation as on mode 4.

Mode 7: Choirverb - a "shimmer" reverb with verb level on 1, low cut on 2, and octave up & down on knob 3.

Mode 8: 4th/5thverb - reverb level on knob 1, 4th down on knob 2, 5th up on knob 3. This doesn't show quite as much on the video but this is definitely the most organic/analog synth-sounding patch of these 8 (in my opinion)

Now the footswitches: the left switch is a "master on/off" that bypasses the entire circuit.

The right switch kills the input to the effect chip and allows the reverb/delay/choir to trail off naturally. HOWEVER - this will keep the dry blend knob in play and depending on where you have it set, this knob can boost the heck out of your signal. Which can be a good or bad thing... up to you.

Are any of these sounds "usable"? That's a matter of taste, of course, but at the very least, NONE of them are delicate. Thanks for reading this far...

-Chris, CDCE

 



Saturday, 4 March 2023

Colorsound Vocalizer

 A rare bird in the Colorsound range. Some additional mods can be made. Replace the 3,9k resistor with a 10k pot for a Freq control. And try a PNP Germanium for Q1 which smoothens the feel of the formant filter..

Schematic is avaiable HERE.



Saturday, 29 October 2022

Electro Harmonix Bassballs / PedalPCB Lowballer Twin Envelepoe Filter

 It s time for a guest appearance!

Chris Stelloh of Capitalist Death Cult requested a layout for this one a while ago but I couldn't do it at the time so he went off and did his own. The layout is verified and good to go.

It is basically a EHX Bassbals with quite a few mods by PedalPCB. The internal trimpots are now extrenal pots. The Attack, Decay and the the distortion section are addons that wasn't included in the original Bassballs.



Monday, 27 December 2021

Korg FK-2 Mr. Multi

 Another weird one! A rotary selector selects between a four stage phaser, wah and phaser and wah combined. The latter mode is supposed to be something out of this world. Deadend Fx (who else) have a projects for this beast and as usual, don't hesitate to support these guys by bying some nifty PCBs. They also included some useful mods such a Depth control for the LFO and two trimpots to fine tune the LFO and the sweep of the wah pot. Build docs, schematic and setup guide HERE.

And HERE is the stock schematic.


 



Sunday, 26 December 2021

Keio Synthesizer Traveler F-1

 An old, obscure, weird fuzz/wah/filter/noise/volume pedal from Japan dated from the the early 70s. Schematics and more info HERE. Note that a couple of resistor values was is incorrect in the original schematic but it has been corrected for the layout below.



Tuesday, 26 October 2021

Schumann F Loop

 Here is a an old, rare and weird one traced by Deadend Fx.

It is a feedback looper that includes both modulation and an active filter sections. If you you don't like the hassle with the offboard wiring this layout requires, Deadend Fx has nifty PCBs for sale.

Schematic and more info HERE.


 




Tuesday, 31 August 2021

DOD Envelope Filter 440 Reissue

 Per request. This is supposed to a great envelope filter with both up and down sweeps.

Schematic is avaiable HERE.


 




Monday, 30 August 2021

Guyatone WR3 Wah Rocker

 A fairly simple to build auto wah that is supposed to sound really good.

Schematic is avaiable HERE.