Shallow Water in the 301, how would you approach this build?

Hi there!
Long time lurker, first time poster.

I have had the marvelous ER-301 for a solid couple of months, watched all of Neil’s & Joe’s videos (thank you heaps for those, they were key in my progress with the module), gave a fair chance to most of the custom units available here, and for the first time tried building my own custom unit based on a guitar pedal effect… and failed miserably.

So I am hoping a kind soul can shed some light on how an effect like the Shallow Water could be created in the ER-301.


Based on a traditional analogue chorus/vibrato circuit, the Shallow Water varies the delay and filtration created in relation to the input signal, simultaneously giving an old-tape-like warmth and sporadic flutters of pitch and modulation (further info and the circuit schematics can be found here:


First trouble I encountered was the lack of Anti-alliasing filters on the 301, but even without this piece of the puzzle I could not get to anything remotely similar to what I was expecting.
I would appreciate any insight, help, or experiments.

1 Like

I’m curious what your approach was for generating the psuedo-random modulation?

You might try opening up my Trash Tape custom unit. It might give you ideas for tape style random modulation. You could also try sending an envelope follower to the Age parameter. I’ve never used a Shallow Water so I’m not exactly sure how it works but this might get you close

1 Like

One idea for pseudo random:

Get a regular-shaped LFO (like a sine), maybe modulate its speed a tiny amount, and then have an S&H sample it at slightly modulated intervals, and apply a slew limiter with slightly changing slew times?

That way, you can do things like: “a downward modulation is followed by an upward modulation, but not always. And the fluctuation is fairly regular, but not always. And the wobble is never drastic, but feels alive”.



To be honest I just went full on random, with white noise and a slowly clocked sample and hold…

That is certainly a smarter approach than the one I had. Much more refined and closer to the pseudo-random nature of the Shallow Water. Will try it out as soon as I get back home today!
Thanks for the suggestion

1 Like

I love your Trash Tape unit, it actually was the last push to make me part ways with Magneto…
Outstanding work!!! Thanks for creating and sharing it.
Will try the approach you suggest, and give a shot at reverse engineering the custom unit to fit my needs instead of building it from scratch.

1 Like