[sdiy] BBD clock bleed

Quincas Moreira quincas at gmail.com
Tue Oct 23 16:36:12 CEST 2018


Great info folks, thanks very much! I think for this video I will heed
Erica's request and keep it as a flanger or slapback. It sounds pretty
awesome doing that !  I already have two Pico DSP and one Erica digital
delay for the longer repetitions...

Cheers and a great day to all!

Q



On Tue, Oct 23, 2018 at 9:26 AM <rburnett at richieburnett.co.uk> wrote:

> I doubt that pursuing any sort of "out-phasing" technique like that to
> reduce the clock feed-through would ultimately be very fruitful.
>
> The amplitude of the clock feed-through likely depends on the
> instantaneous clock frequency.  The phase shift of the feed-through may
> also vary with frequency, and your integrator to convert the clock from
> square to triangle would add 90 degrees worth of phase shift to start
> with anyway...  It would therefore be hard to achieve any significant
> degree of cancellation over a range of clock frequencies, in my opinion.
>
> I'd be looking at a static LPF or some sort of tracking filter to remove
> the clock feed-through, once I was happy that the original design was
> working properly, or at least as good as it can do.
>
> -Richie,
>
>
>
> On 2018-10-23 14:36, Quincas Moreira wrote:
> > I’ve thought of using na integrator to derive a triangle from the
> > clock pulse, then an OTA to distort it into a sine, then invert it and
> > sum it to the BBD output thus cancelling most of the bleed but now
> > we’re talking a full on daughterboard, lol
> >
> > Sent from my iPad
> >
> >> On Oct 23, 2018, at 8:12 AM, Tom Bugs <admin at bugbrand.co.uk> wrote:
> >>
> >> There appears to be minimal input and output filtering also.
> >>
> >>
> >>> On 23/10/2018 14:07, Vladimir Pantelic wrote:
> >>> no output balance trimmer between out1 and out2 on this one
> >>>
> >>>> On 23.10.2018 14:46, Quincas Moreira wrote:
> >>>> Sorry Folks, please follow this link
> >>>> https://drive.google.com/open?id=1O5kKkaJZqom61W8WQKQCfm3gLF83goz0
> >>>>
> >>>> Sent from my iPhone
> >>>>
> >>>> On Oct 23, 2018, at 06:13, Tom Wiltshire <tom at electricdruid.net
> >>>> <mailto:tom at electricdruid.net>> wrote:
> >>>>
> >>>>> The list strips attachments. Can you post a link?
> >>>>>
> >>>>>
> >>>>>> On 23 Oct 2018, at 08:30, Quincas Moreira <quincas at gmail.com
> >>>>>> <mailto:quincas at gmail.com>> wrote:
> >>>>>>
> >>>>>> thanks folks. It’s a new
> >>>>>> module, not yet released V3205 based. Strange that you don’t see
> >>>>>> the
> >>>>>> pdf attachment, I’ll try again in the morning
> >>>>>>
> >>>>>> Sent from my iPhone
> >>>>>>
> >>>>>> On Oct 22, 2018, at 23:59, Pete Hartman <pete.hartman at gmail.com
> >>>>>> <mailto:pete.hartman at gmail.com>> wrote:
> >>>>>>
> >>>>>>> As others have said a lot depends on which BBD we're talking
> >>>>>>> about.
> >>>>>>>
> >>>>>>> Most of my BBD experience is with Blacet's Time Machine.  It uses
> >>>>>>> the MN3005 which has balanced outputs, which can be trimmed to
> >>>>>>> minimize the clock bleed, and it also uses clock dependent
> >>>>>>> filtering
> >>>>>>> and compansion to help reduce the noise further.  I have also
> >>>>>>> played
> >>>>>>> some with the Doepfer A-188-2 which uses a tapped BBD, and that
> >>>>>>> does
> >>>>>>> *not* have balanced outputs, so the bleed is harder to tame.
> >>>>>>>
> >>>>>>> I looked at the Erica site as well, and honestly, I can't tell
> >>>>>>> which
> >>>>>>> one you're asking about either.  Let us know/attach the schem,
> >>>>>>> and
> >>>>>>> I'm sure someone will have suggestions :)
> >>>>>>>
> >>>>>>> Pete
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>> On Mon, Oct 22, 2018 at 8:55 PM Quincas Moreira
> >>>>>>> <quincas at gmail.com
> >>>>>>> <mailto:quincas at gmail.com>> wrote:
> >>>>>>> Hey friends! I'm working in a review of the new Erica Synths BBD
> >>>>>>> module, and I'm getting massive bleed of the clock frequency
> >>>>>>> (though
> >>>>>>> it looks sinusoidal rather than square)
> >>>>>>> Any tips on minimizing this bleed? Anytime the clock steps into
> >>>>>>> audible range it's super loud
> >>>>>>>
> >>>>>>> Schematics included...
> >>>>>>>
> >>>>>>> Thanks!!
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>> --
> >>>>>>> Quincas Moreira
> >>>>>>> Synth Diy Guy
> >>>>>>> _______________________________________________
> >>>>>>> Synth-diy mailing list
> >>>>>>> Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org>
> >>>>>>> http://synth-diy.org/mailman/listinfo/synth-diy
> >>>>>>> _______________________________________________
> >>>>>>> Synth-diy mailing list
> >>>>>>> Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org>
> >>>>>>> http://synth-diy.org/mailman/listinfo/synth-diy
> >>>>>> _______________________________________________
> >>>>>> Synth-diy mailing list
> >>>>>> Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org>
> >>>>>> http://synth-diy.org/mailman/listinfo/synth-diy
> >>>>
> >>>> _______________________________________________
> >>>> Synth-diy mailing list
> >>>> Synth-diy at synth-diy.org
> >>>> http://synth-diy.org/mailman/listinfo/synth-diy
> >>>>
> >>> _______________________________________________
> >>> Synth-diy mailing list
> >>> Synth-diy at synth-diy.org
> >>> http://synth-diy.org/mailman/listinfo/synth-diy
> >>
> >> --
> >> BugBrand LTD
> >> UK company No. 07199808
> >> VAT No. GB 988 2629 57
> >> 1 Ninetree Hill
> >> BRISTOL BS1 3SB
> >> United Kingdom
> >> www.bugbrand.co.uk
> >>
> >>
> >> ---
> >> This email has been checked for viruses by AVG.
> >> https://www.avg.com
> >>
> >> _______________________________________________
> >> Synth-diy mailing list
> >> Synth-diy at synth-diy.org
> >> http://synth-diy.org/mailman/listinfo/synth-diy
> >
> > _______________________________________________
> > Synth-diy mailing list
> > Synth-diy at synth-diy.org
> > http://synth-diy.org/mailman/listinfo/synth-diy
>


-- 
Quincas Moreira
Synth Diy Guy
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20181023/9bf06ce1/attachment.htm>


More information about the Synth-diy mailing list