Doepfer

i would start testing without using a modulator and only with
a very simple input signal (a single vco wave).

first reduce the feedback to zero.
dial in a very short delay time and you should not hear
any clock noise coming through. then decrease the delay time
manually and write down the knob setting when the clock noise
gets audible (knob should be around 12 o'clock position).
if you get a different result then please post your
knob setting here.

after that you should try a slow modulator (f.e. an lfo)
as adviced by adam-v.
one important point regarding envelopes, some env modules
spill out up to +10 volts, so sometimes it is necessary to
attenuate the envelope signal, otherwise the hsvco may
reach frequencies where the bbd chip starts doing strange things.
this is of course also depending on the type of bbd chip,
not all chips show the same reactions.

if you want to filter out the clock noise, then use the
cv output of the bbd module and feed it into the cv input of a
lowpass filter. feed the bbd output into the filter input and use
the filter output as your new delayed signal. use the steepest
lowpass filter that you have in your system. the steeper the
filter the more high fequencies are left in the signal.
if you want to get more clean results, then you can use
another lowpass in the same manner to filter the bbd input signal.
this reduces aliasing noises, but has nothing to do with the
clock noise.

best wishes

ingo



--- In Doepfer_a100@yahoogroups.com, "Adam-V" <adam-v@...> wrote:
>
> Seems a bit strange to me. 
> 
> I would start from scratch and just patch a VCO into the BBD input 
and
> monitor the BBD output whilst manually tweaking the delay time to
> check the basic functionality of the module. Then I would try an LFO
> to modulate the delay time to determine that the CV2 input is
> functioning correctly. If that works then I would re-try the 
envelope
> generator just to be sure I had actually connected it properly. 
Then I
> would try a different envelope generator or perhaps recheck the
> envelope generator settings.
> 
> One other thought, the feedback isn't set to a point that the BBD 
is 
> self-oscillating is it?
> 
> Perhaps one of the other members can offer up further ideas.
> 
> Cheers,
> Adam-V
> --- In Doepfer_a100@yahoogroups.com, "regimental1200"
> <regimental1200@> wrote:
> >
> > Sorry, I'm at work now and was just not refering to the correct 
> > jack.  I basically take the output of an envelope and I stick it 
> > into CV2 of the BBD module.  I also dial-in a bit of feedback.  
> > Beyond that, only the MIX OUT is connected.
> > 
> >
>