A disaster!  The following csd gives discontinuities every k-cycle on  
both channels

Looks like time for significant investigation
==John ff


Quoting jpff@cs.bath.ac.uk:

> Well you could try the butlp with a-rate cutoff frequency to see if  
> it still happens.  That code is in git now.
> ==John ff
<CsoundSynthesizer>
<CsOptions>
-d
</CsOptions>
<CsInstruments>

0dbfs=1
nchnls = 2
ksmps = 1000

instr 1
koct lfo 3,4,0
aoct oscil 3,4
asig vco2 0.5,400,4,0.5

asigk butlp asig,cpsoct(7+koct)
asiga butterlp asig,cpsoct(7+aoct)

outs asigk,asiga
endin

</CsInstruments>
<CsScore>
i1 0 10
e
</CsScore>
</CsoundSynthesizer>