"Sewer Pipes Ring-Verb" Simple PT2399 One-Knob Effect

[Earthscum]

This is kind of a spinoff of anchovie's "Noise Ensemble". I love the simplicity of it.

When I was playing around with that circuit, I really liked the reverb sound. I had troubles isolating it, so I started over with the base for the Little Angel, since I had a ton of 10k's sitting there taunting me to do something with them. I had to put a bit of filtering in, but if you don't mind hissing, you can pop out the 13/14 and 15/16 1n caps.

So, after a couple hours of tinkering between shows and cooking dinner, I came up with this. It's kind of like playing in a sewer tunnel... or at least that's what it reminds me of. The 10k pot controls how much of an effect you get.

The optional Resonance Control is my first mod. It came about while trying to tame a bit of the resonance, obviously... but I actually like the control. You can go from a ringy tone to a duller ring. Extraordinary, isn't it?!? 

Enjoy!

[Slade]

Awesome! Another PT son!
I have so much to BB now...
I hope somebody post some demos when trying it

[Earthscum]

Quick note: When I was playing with this, I found out that this batch of PT's like to latch up the oscillator on powerup if you use anything less that 1k on pin 6. You still get sound, everything seems to work, but there's no delay signal. I tried it in a standard setup, as well. Tried battery, also. Same thing. When I'd turn it on, I'd get 2 pops instead of the typical click.

BTW, I forgot a 1M on the input before the cap. I wasn't using one (which may be part of the latching problem I was seeing). I'll be playing around with it a little more tonight after work.

Oh yeah... one last note... this should work on guitar, but I have not tested it with one yet. Works awesome with bass, for sure!

[earthtonesaudio]

I had an issue once where the PT appeared to latch up, but it turned out to be an overheating 5V regulator.  Just thought I'd throw that out as a possibility if you hadn't already ruled it out.

[Earthscum]

I had an issue once where the PT appeared to latch up, but it turned out to be an overheating 5V regulator.  Just thought I'd throw that out as a possibility if you hadn't already ruled it out.

Good call. I was constantly checking the heat when I was building. I had absolutely no issues until I tried the Little Angel 100R on pin 6. Then I swapped out chips, and still had the issue. I just popped in a 100R and fired it up cold, and it works.

The delay resistor makes the biggest difference in the amount and tone of the ringing. This is a definite "flavor to taste" part.

[anchovie]

Any demos of this forthcoming?

[Earthscum]

Any demos of this forthcoming?

What's a decent free clip hosting site? I don't wanna put up a tube video...

I'll get a clip done up tonight, after work.

I didn't do much last night, except watched "Men Who Stare at Goats", but kept having to plug in and play through it, so I think I'm gonna be boxing this one up. I wasn't too sure about the usefulness of the sound for what I play until I threw my Fuss in front of it... Wow! At minimum settings, it takes it a little into the flanged metal sounding distortion. Basically it sweeps from sounding like you used a pie-tin for a speaker cover to playing in a giant corrugated steel pipe.

[Earthscum]

Decided to try zSHARE. We'll see how it works.

Demolition clip 1:

Sewer Pipes Demolition Clip.mp3 - 1.22MB

Riff from one of our songs, recorded on Acid (Pro 6), Ibanez Soundgear GSR205 straight into the Sewer, out to a DOD FX91 set up as a flat booster, to the comp through a ST Audio ADC&DAC2000. But does all of that matter? Probably not, lol...
1: Dry
2: SP, knob at '0'
3: SP, knob at about 11 o'clock
4: SP, full on, "cranked to 11!!"

Also, since I had it all hooked up, here's the Bazz Fuss in front of the Pipes:
(same effect order, but I did someone else's song in 4 sections so you can hear how this reacts to higher frequency content)

Sewer Pipes Bazz Demolition Clip.mp3 - 1.29MB

In hindsight, this could probably be a better sweep with a log pot. Also, in the schem, the output cap should be .1uF, not 1uF. Also, I found that in the mod (which is kind of a subtler mod), a 4.7k works a little better than a 10k. The 50k pot is still ok, unless you have one that is around 75k or so.

Oh yeah... I found something out tonight... this did NOT like me turning down my tone control (it would start oscillating and go into runaway feedback), so this could definitely benefit from a simple input buffer, or coming after a buffered effect. This entire circuit is basically relying on feedback to cause effect to the audio signal... kind of like a gyrator. The 33k resistor controls how much total resonance you get, and if you want a noise machine, drop it to 22k-10k. Then you go the sweep I demo'd, all the way to oscillations that you can control with the knob.

So whatcha think?

[Taylor]

Sounds awesome. I've used my FV-1-based digital delay to get these kinds of sounds, but it's very cool to be able to do it with a 60 cent part instead of a 10 dollar chip. 

I'm really pleased to see all of the fun recent projects with the PT2399.

[Manny]

Another great looking PT2399 build!
Once I finish my Noise Ensemble I'll give this a try 

[Skruffyhound]

Sounds interesting, and still room for more mods
Good work

[defaced]

I'm starting to think the 10 PT2399s I ordered from Tyada won't be enough, cause this one is going on the "to build" list. 

[Brymus]

Yeah sounds good ,another cool PT2399 circuit.

[frequencycentral]

Another great sounding PT project. I particularly liked the second 'Bazz' clip. Anyways, layout! Please someone check it for dumb errors. I added a 1M pulldown at the input. Some of the cap values I found hard (Is that a decimal point? No wait, it's moving, must be an electron) to read - tiny schematic! The optional resonance can easily be added off-board. Enjoy!

[Earthscum]

Looking at it, everything is hooked up correctly. That's awesome!

If you wanna box this up with a higher gain boost or distortion on the front end, R9 is in a perfect location to install an output pot (the reason I selected 100k).

Another fun for the noize freaks is to replace R7 (33k) with a 50k pot and a 10k-22k resistor in series. You can take the resonance from hardly there to solid feedback that is fun to play with. Basically ringing feedback that can be set where you want it and flavored with another note or two, then decayed slowly with the twist of a knob. This one may be worth modding to use with an expression pedal of some sorts, or some kind of remote control.

Thanks a bunch, Rick!

[askwho69]

nice! to me im hearing echo like in mic?

[DavenPaget]

Sorry for bumping 
David , thanks for the reverb , it's so simple 

[Earthscum]

Thanks! It's definitely got it's own sound to it. I got bored one night and ran a soundclip of a passing train blowing it's horn through it for about half an hour, playing with the knobs... sounded just like it was coming down a tunnel at you, lol! It was pretty fun. 

[DavenPaget]

Oh yes , does the 50k resonance pot really need to be logarithimic pot ?

[PereatMundus]

Nice thing this

so tiny!! ...

hmm ..

What would happen if one where to put a Little Angel, Sewer Pipes, and rebote 2.5 ALL in a 1590A.. with micro DPDT toggles..
that...
could fit..


Off-topic:

One PCB ontop the other..
like this OC-2 layout (fits 1590A)
http://www.aronnelson.com/gallery/main.php/v/Renegadrian/chopped+oc2.pdf.html

insanity.. but a funny all in one FXloop 1590A pedal....
I like that thought, but 


If it wasnt for those pesky too big 9mm alpha pots    one "could" fit much more stuff in a 1590A .
a Delay+Reverb+Chorus PT2399, 1590A pedal ... would be.. kind of cool..