ERROR: Out input at index 1 ( 2 ) is not audio rate

I hope to find help with an error message, which I do not understand:
ERROR: Out input at index 1 ( 2 ) is not audio rate

To me the setup looks as if I only use audio buses.
The goal is a simple mixer synthdef with some fx sends and feedback returns (note to myself: have to re-label send volume).

(
//setup some busses
s.newBusAllocators;
~mxch01 = Bus.audio(s, 2);
~mxch02 = Bus.audio(s, 2);
~mxch03 = Bus.audio(s, 2);
~mxch04 = Bus.audio(s, 2);
~fxbus01 = Bus.audio(s, 2);
~fxbus02 = Bus.audio(s, 2);
~fxbus03 = Bus.audio(s, 2);
~returnbus01 = Bus.audio(s, 2);
~returnbus02 = Bus.audio(s, 2);
~returnbus03 = Bus.audio(s, 2);
~ctrbus01 = Bus.control(s, 1);
~ctrbus02 = Bus.control(s, 1);
~ctrbus03 = Bus.control(s, 1);
)

(
SynthDef(\mxr, {
  arg in1 = ~mxch01,  in2 = ~mxch02,  in3 = ~mxch03,  in4 = ~mxch03,
      fxo1 = ~fxbus01, fxo2 = ~fxbus02,fxo3 = ~fxbus03,
      rtn01 = ~returnbus01, rtn02 = ~returnbus02, rtn03 = ~returnbus03,
      stereo_out = 0,
      vol1 = 1 , vol2 = 1 ,vol3 = 1 , vol4 = 1,
      fbk1 = 0, fbk2 = 0, fbk3 = 0, 
      out_vol = 1;
  var input1 = In.ar(in1,2) * vol1;
  var input2 = In.ar(in1,2) * vol2;
  var input3 = In.ar(in1,2) * vol3;
  var input4 = In.ar(in1,2) * vol4;
  var rtnbs1 = InFeedback.ar(rtn01,2);
  var rtnbs2 = InFeedback.ar(rtn02,2);
  var rtnbs3 = InFeedback.ar(rtn03,2);
  var snd1 = Out.ar(fxo1, 2) * fbk1;
  var snd2 = Out.ar(fxo2, 2) * fbk2;
  var snd3 = Out.ar(fxo3, 2) * fbk3;
  var sig = (input1 + input2 + input3 + input4) * out_vol;
  Out.ar(stereo_out, sig);
}).add;
)

Edit: I narrowed it down to the

var snd1 = Out.ar(fxo1, 2) * fbk1;
...

ā€˜2ā€™ is not audio rateā€¦ This is an annoying sclang-ism that could probably be fixed for you. Out.ar(fxo1, DC.ar(2)) that should do the trick (away from pc canā€™t test).1

1 Like

Thanks @jordan, you pointed me in the right direction. I had misinterpreted the manual. the second parameter expects a ā€œchannels arrayā€ and my brain turned it into array size value for some reasonā€¦ More sleep might help :stuck_out_tongue: