Yahoo Groups archive

Doepfer

Index last updated: 2026-04-29 00:15 UTC

Message

Re: [Doepfer_a100] Re: a-112 - cv recording?

2009-01-27 by James Husted

I don't think it would be very hard to modify a typical Audio A/D  
converter design to do the job needed here. Remove the AC coupling,  
change the input scale to handle +/-5 Volts and keep it sampling at  
96k and 24bits. My math has never been my strong suit but I imagine  
24bits should cover a 10volt swing pretty easily with the resolution  
needed, and 96kHz should be fine enough timing wise. This could almost  
be done with an adaptor that precision scaled the analog +/-5V down to  
a range that a typical computer A/D could handle (and of course do the  
opposite for the output) and you could then use any interface that  
wasn't AC coupled (hard to find apparently). In any case I can't see  
it being that hard for a company to make a A/D converter that can  
sample modular CV ranges at the speed that typical audio interfaces do  
now and shoot the info to a DAW in a format it could understand.  Like  
I've said before on this list - if the Volta take off you will see a  
hardware solution very soon after. It is not like they have to invent  
something from the ground floor.
-James


On Jan 26, 2009, at 4:17 PM, achtung_999 wrote:
>
> > I would say that 22.5 KHZ would already be quite sufficient for
> > > tracking CV,
> > > everything above that is luxery.
> > >
> > Oh no, certainly not. I'd say 44KHz or thereabouts is the absolute
> > minimum... I leave the math explanation to the math-oriented  
> people in
> > here. My coffee has already worn out...
>
>
> Yes I know that. And that still does not answer my question really..
> Let's say we have an pseudo-ideal CV> digital converter. It would  
> work from
> 0 volts to anything, so no upper limit. (Just assume this..)
> I would shift the CV up by the amount it needs to have the most  
> extreme
> negative amplitude point to be 0 volts.
> Let's assume this is 5 volts. My device now tracks it nicely and  
> records it
> in whichever imaginative software format we might think of.
> I now would like to use this signal to drive my modular.
> I would take the output from the software via my reverse device and  
> shift
> the resulting voltages down 5 volts..
>
> In my opinion this would not be different than the original signal.  
> would
> it?
> Sorry if I was unclear about this.
> And yes, I know it's a hassle ;-)
>



[Non-text portions of this message have been removed]

Attachments

Move to quarantaine

This moves the raw source file on disk only. The archive index is not changed automatically, so you still need to run a manual refresh afterward.