Parameters that don't seem to do anything

I've tried using the built-in accelerate parameter in a huge number of ways -- with and without n, with synths and with samples, over all kinds of value ranges -- and it never seems to do anything.

I also tried to add the muffle parameter, which superpiano suposedly uses, and can't get it to do anything either. I made this change:

--- a/bin/generate-params.hs
+++ b/bin/generate-params.hs
@@ -226,6 +226,7 @@ genericParams = [
   ("f", "vcoegint", ""),
   ("f", "vibrato", ""),
+  ("f", "muffle", ""),
   ("f", "vrate", ""),
   ("f", "voice", ""),

and then running runhaskell generate-params.hs > ../src/Sound/Tidal/Params.h from the root directory. Now muffle is recognized by Tidal but also doesn't seem to do anything.

What's am I missing?


this works?

d1 $ s "superzow" # n  "c" # accelerate 1

OTOH, this looks like superpiano should accept this as well: SuperDirt/default-synths-extra.scd at 15f26e33a06f2a7a42cf4b1f9756e99d14a8a376 · musikinformatik/SuperDirt · GitHub .. but this does not: sc3-plugins/MdaUGens.cpp at fa550fbbe28f78ac1872ed580b21b78ef6b63c42 · supercollider/sc3-plugins · GitHub . Or does it? What does this mean:*, accelerate, sustain)+0.01,

Ah, there was a recent change Apply DirtFreqScale to default synths by ndr-brt · Pull Request #247 · musikinformatik/SuperDirt · GitHub that introduced some extra parameters, but I did not update my local superdirt, so I don't have it? Also, `accelerate` not working with synths · Issue #254 · musikinformatik/SuperDirt · GitHub

Well, I updated SuperDirt (version and updating · Issue #171 · musikinformatik/SuperDirt · GitHub) and this broke accelerate for superzow. Huh.

I don't know what's going on exactly, but keep in mind "superpiano" hooks into the MdaPiano UGen, which unlike almost every other Supercollider synth internally rounds the frequency input to the nearest MIDI note and I don't think supports any kind of pitch glide (like accelerate). So "superpiano" is always going to have odd behavior.

Accelerate works fine for me on other synths but I think my SuperDirt is a actually a bit out of date, so I should check on the newest version.

Not for me.

Is anyone using their own custom parameters for anything? As suggested in the docs for SuperHammond, I just tried using vrate and vibrato, which I defined the same way as described in the OP in this thread, and while they do something it doesn't sound like vibrato at all.

My SuperDirt and Tidal are both up to date:

Tidal --
commit 9f86bc9aa03251065de988e57ffd209665a3acff (upstream/main, origin/master, origin/HEAD, master)
Author: Alex McLean <>
Date:   Tue Jan 11 22:14:43 2022 +0000

SuperDirt --
commit ab4a7dcbcb96a937d1f796f0cb8ac44a38e18e39 (HEAD -> develop, origin/develop, origin/HEAD)
Author: Julian Rohrhuber <>
Date:   Thu Jan 27 09:08:33 2022 +0100