Sweepable low pass filter pedal

[DGWVI]

There's the Tim Escobedo 9v MS-20 LPF (the Barn Owl is basically an amped up version) but the Escobedo version uses less parts and runs of standard 9v. Haven't built this version, but it sounds great, if these videos are anything to go by

The attached PDF is for a similar 9v voltage controlled LPF, couldn't find much info on it, but here's a video -

And, an Archived copy of designer's site

 

[Chuck D. Bones]

CryBaby is a variable low-pass filter. The tuning range and Q are easily tweaked.

 

[EthanRoppBass]

CryBaby is a variable low-pass filter. The tuning range and Q are easily tweaked.

Do you think it could be tweaked to have more resonance and synth like character to actually be used like I want?

 

[Chuck D. Bones]

You're kidding, right? The CryBaby has a Q around 10. That's kind of a lot. Referring to the Tear Jerker schematic, you can maximize Q by

1. Installing a high-Q inductor.
2. Turning the Q pot all the way up.
3. Using a tantalum cap for C3.
4. Using silver-mica or film caps for C5-C13.

Another very good Wah pedal is the Tychobrahe ParaPedal (PPCB Parasite). On that one, you can tweak the Q up until it oscillates if you want. The ParaPedal is basically the same design as the filters in analog synths. And it can be easily modded for LP, BP & HP outputs.

 

[Aentons]

You're kidding, right? The CryBaby has a Q around 10. That's kind of a lot. Referring to the Tear Jerker schematic, you can maximize Q by

1. Installing a high-Q inductor.
2. Turning the Q pot all the way up.
3. Using a tantalum cap for C3.
4. Using silver-mica or film caps for C5-C13.

Another very good Wah pedal is the Tychobrahe ParaPedal (PPCB Parasite). On that one, you can tweak the Q up until it oscillates if you want. The ParaPedal is basically the same design as the filters in analog synths.

Mine already has those knobs built in. The 535Q is super great.

Parapedal is the one that Iommi uses. Ive always wanted to try it but never had the chance.

 

[EthanRoppBass]

You're kidding, right? The CryBaby has a Q around 10. That's kind of a lot. Referring to the Tear Jerker schematic, you can maximize Q by

1. Installing a high-Q inductor.
2. Turning the Q pot all the way up.
3. Using a tantalum cap for C3.
4. Using silver-mica or film caps for C5-C13.

Another very good Wah pedal is the Tychobrahe ParaPedal (PPCB Parasite). On that one, you can tweak the Q up until it oscillates if you want. The ParaPedal is basically the same design as the filters in analog synths. And it can be easily modded for LP, BP & HP outputs.

Oh shit I didn't realize the Q factor is resonance. And I thought that the dunlop wahs were band pass, I guess I was wrong on that. Idk as I said earlier I am currently using the dunlop mini bass wah, but it isnt really getting the character I want. Do you have any advice on mods that would make it sound more like a proper analogue synth filter? I guess I can try what you mentioned to max out Q

 

[Chuck D. Bones]

The mods I suggested will increase the Q, but you can take that circuit only so far. The CryBaby kinda sounds like a bandpass because of the resonant peak. A true bandpass will sound "thinner" because with a low-pass, the bass is always present.
If you're going for a synth sound, then the ParaPedal will get you there with the least amount of effort. I suggest that you breadboard it to see if you like the tone and so you can try some simple mods. Then if you decide you want that in a Wah enclosure, look for a broken CryBaby that you can cannibalize for the housing and gears.

 

[EthanRoppBass]

I'll check it out. Its also tempting to just wait until I have a little more experience and build that Tresonator from DeadEndFx. Either way, thanks!

 

[Aentons]

A parametric eq with an expression pedal for the frequency will get you those synthy filter sweeps too.

 

[Diynot]

When you say “synth like” what is your baseline tone? For subtractive synth I usually do the octave pedal->envelope filter->square wave fuzz. If that is what you are after, consider the Madbean Junktrunk when he gets restocked. It’s an OTA envelope filter and excels at getting those slow sweeps and is for bass so no loses in the low frequencies. I recently built a tearjerker wah using Chuck’s bass mods and it can def get dubby (I just need to tune the wah pot a little). There is also the MBP Edgelord that is pretty awesome

 

[EthanRoppBass]

When you say “synth like” what is your baseline tone? For subtractive synth I usually do the octave pedal->envelope filter->square wave fuzz. If that is what you are after, consider the Madbean Junktrunk when he gets restocked. It’s an OTA envelope filter and excels at getting those slow sweeps and is for bass so no loses in the low frequencies. I recently built a tearjerker wah using Chuck’s bass mods and it can def get dubby (I just need to tune the wah pot a little). There is also the MBP Edgelord that is pretty awesome

I am using bass-> octave or pigtronix mothership 2-> ring modulator ->bass wah. And as far as the Junktrunk, I am looking for something I can manually sweep, so for an envelope filter I want an expression pedal. It does look like a sick pedal though.

 

[Feral Feline]

You could install a jack that interrupts the SWEEP pot of the Junktrunk when an expression-pedal is plugged in.