VA1Pole has DC == feedback coefficient at output in LPF mode

[catniptwinz]

Describe the bug
In mode 0 (lpf), VA1Pole has a DC offset equal to its feedback coefficient at its output.

To Reproduce
Evaluate each example and observe the posted values.

{ VA1Pole.ar(Silent.ar, 500, MouseY.kr(-0.99, 0.99), 0).poll * 0 }.play // lpf
{ VA1Pole.ar(Silent.ar, 500, MouseY.kr(-0.99, 0.99), 1).poll * 0 }.play // hpf

Expected behavior
If any DC offset is present at the output of VA1Pole, it will be quite small, as in the HPF example above.

Desktop (please complete the following information):

• OS: Arch Linux (5.14.9-arch2-1)
• Architecture: x86
• SC Version: 3.12.1
• PortedPlugins Version: 0.3.0d-1 (from AUR)

[madskjeldgaard]

Wow - nice catch. Thanks for reporting!