#53 - Chaos Machine

[airbud]

Build Rating

5.00 star(s)

This was a pretty easy build, with the only exception that I soldered the pots in three stages rather than trying to align all 27 pins to the PCB at once.

It sounds cool, but I do get a cyclical whooshing sound in the background while everything is maxed for each filter (intensity, resonance, mix). Once you dial back some of the knobs, the background noise diminishes. My minor frustration is that I can either get no noise and a subtle sound, or noise and more wackiness. I've not yet done a proper QA but did swap out a crappy Amazon JRC4558 for a nicer/real one, but to no avail.

I think I'm learning that a lot of these circuits don't really "work" once you start maxing our the knobs. Usually it's been an ultra mega gain circuit, but I can see how cranking the resonance would generate some background whoosh on top of even a little bit of noise.

I did sub 470n for C3 and C4, as per posts discussing this build for bass, so that may contribute.

Overall it's a cool pedal, wouldn't call it a must-build but I'm a sucker for the wacky EQD stuff. 1590XX's are so spacious too

 

[ColorMeBaddFann]

Did you manage to work out what was causing the "whooshing" sound? Just finished putting this one together and I get the same result, but seem to get it through all settings, not just maxed. Going to try another 4558 than the one I got from Tayda, but sounds like that didn't make much difference in your situation.

 

[KreoPensas]

All of the threads I have seen on the topic lead to a conclusion : the wooshing is part of the effect's character. It also sounds to me like no two builds are really identical.

I really love this effect. It can be used in parallel with a noise gate after it if the idle woosh is bugging you.

 

[fontoponto]

This is a nice Phaser!
I added a switchable 10u to C10 to have a slow real slow experience.

 

[ColorMeBaddFann]

All of the threads I have seen on the topic lead to a conclusion : the wooshing is part of the effect's character. It also sounds to me like no two builds are really identical.

I really love this effect. It can be used in parallel with a noise gate after it if the idle woosh is bugging you.

Makes sense. Although mine ended up with wayyy too much whoosh. Didn't matter the settings, it dominated the output.

Sure enough, tried changing the 4558 from the cheap Tayda part to one I got from GPCB and it quieted way down. Pretty much as airbud described. Now it sounds great.

 

[KreoPensas]

It is worth the extra trouble to add expression pedals. The rate control needs 1 mohm, I took a $20 Nektar expression pedal from Amazon and put a 2 mohm pot in it so the resulting travel is close to 1 mohm. If you turn the amount/intensity control of one of the filters all the way down, it then only responds to the pedals, while the other will ride the lfo. That really gets it talking.

 

[Deperduci]

the whooshing might be the jack wires crossing the board, I have some madbean boards he tells you in the build instructions to watch for that and try to keep them to the sides of the enclosure. nice clean build otherwise.

 

[ColorMeBaddFann]

the whooshing might be the jack wires crossing the board, I have some madbean boards he tells you in the build instructions to watch for that and try to keep them to the sides of the enclosure. nice clean build otherwise.

I ran mine around the board but still get the whoosh at higher settings. Guessing KreoPensas is correct that it's just the price of admission.