Hey, I’m currently failing to find the time to improve glut, maybe I’ll get back to it later this autumn. But of course you can easily modify the effect, as it’s in the separate SynthDef: https://github.com/artfwo/glut/blob/master/Engine_Glut.sc#L86-L91
The input (stereo) signal is going by the sig variable, which you can process as follows:
SynthDef(\effect, {
arg in, out, mix=0.5, room=0.5, damp=0.5, delay=0.1;
var sig = In.ar(in, 2);
sig = DelayN.ar(sig, 1, delay);
Out.ar(out, sig);
}
Compare that to original SynthDef linked above. Note the additional delay argument to the effect SynthDef, you might as well want to add engine command for that if you ever want to automate the parameter.
I also suggest getting comfortable with some basic SuperCollider concepts (SynthDefs, buses, etc.) on a desktop machine, you’ll find it easier to play with the engines later.