Porting Madrona Labs' Reverb to 301?

recently madrona labs released a very lovely reverb plugin called altoverb.

i think it sounds great – and apparently it’s pretty lightweight…

the developer, randy jones, was kind enough to make the code available for anyone who would like to port it to other platforms:

I’ve just updated the madronalib source with a couple of new sound examples based on RtAudio. One of these is an Aaltoverb example. If anyone’s interested in porting it to norns (or anywhere), feel free to ask me any questions you have.

The basic algorithm of this is something that I’ve been playing with for a long time, since I made the yafr~ example for Max/MSP (in 2001 or so?) based on the Dattorro paper that gave away the idea behind one reverb “in the style of Greisinger.” (Lexicon)

My newer take on it is that all the allpass delay lines are smoothly modulatable using an idea proposed in “A Lossless, Click-free, Pitchbend-able Delay Line Loop Interpolation Scheme” (Van Duyne, Jaffe, Scandalis, Stilson, ICMC 1997.) So the size can vary from small to large without clicks, which I won’t claim is unique but I don’t hear most reverbs doing.

i’m wondering if a version of this could make it’s way into the 301? i know the C++ layer is currently only accessible to @odevices - so i guess this is a bit of a direct request :wink:



1 Like

Ooooh, sounds lovely! Would be ace to have that one available! :slight_smile:

1 Like

I have nothing to add but some begging. Perty pls?!?

1 Like

I love this idea!

(Just adding to the chorus of enthusiastic supporters.)

+1, I’ve just listened to the demo. Would be cool to have this in the 301

this, if possible. would just be an extra layer of awesome…tom erbe has a few freebies and any new designer would be very wise to offer a few to er301 users to try their algorithms before buying their “x” product, its just how accessible it is to us on the 301


Brian: would this be possible ?

It would really make sense as er301 is a “sound computer” ! :slight_smile:

So should i take the lack of response as being an answer no ? :wink:

EDIT: i mean regarding open source code for fx…

Im sure there’s lots of potential for these type devices such as the er301, but often wonder if they are only mostly meant for people that have the time to learn to program them.

Sorry. I have no concrete answer on this at the moment.

1 Like

I obviously don’t know the big strategy/paradigm of ER301 - is it closed system for 3rd party components, allowing them with some trust, or even future marketplace :slight_smile: but some quality and music reverbs will help. From the other side, I don’t know how much cpu power is needed for quality reverbs. If so much, I will stay with mine OTO BAM and Axe-Fx outside of modular case (I can’t see any quality reverbs in eurorack now).

1 Like

Glad to see this bumped…and yeah, good points. I just hope that good stuff will be shared for the people who arent lucky enough to have had the time/money/ education to learn code.

Seems like porting(is this the right term?) open source code to er301 seems like it would be good for everyone.
Am i right ?


I have no reason to bring this up other than I’m stuck inside and focusing time on the ER-301 and teletype (which I hope to soon add a NerdSeq). Double pretty please!?


I’m not sure how much deep dsp is possible right now since there isn’t an SDK or the ability to implement c++ code yet. I’m also hoping for a slightly better reverb, but reverb is also pretty resource hungry, and my favorite thing about the ER-301 is that it can do multiple things at once, filling in the low spaces of a rack.

1 Like

meanwhile i’d encourage you to take @Joe’s last experiment further by
experimenting with different units in the feedback path he’s showing:

i also can fully recommend to get yourself a Doctor A from Audiothingies for it is exceptionally
suitable for eurorack setups in general and as a dual aux effect for the er-301 in particular.
(2x CV-ins and line-/euro-levels independently settable for ins and outs, dedicated LP/HP filters
for delay and reverb. best thing is: you can route each mono audio in to each effect and mix them
together to a stereo out in the box. and many more. last but not least: it sounds pretty awesome.)


Madrona Labs verb would be divine!!!

And this new @Joe video is equally divine. It’s in the watch list now. :slight_smile: