[LAD] midi beat clock

Tim E. Real termtech at rogers.com
Sat Feb 20 21:44:46 UTC 2010


On February 20, 2010 04:34:29 pm you wrote:
> On Sat, Feb 20, 2010 at 4:22 PM, Tim E. Real <termtech at rogers.com> wrote:
> >> I thought "it's too bad we can't adjust Jack's sample rate on the fly"
> >>  thus allowing Jack to behave like a Voltage Controlled Oscillator in a
> >> PLL, syncing to MTC frame.
> >> I was thinking the VCO 'control' signal would come from a client.
> >> Else Jack itself would have to support MTC.
> >>
> >> But raises the question - which Jack back-ends allow dynamic sample rate
> >>  changes? And with a finite resolution small enough?
>
> none. and AFAIK, only RME hardware allows true varispeed via the sample
> clock.
(Hope the original poster still finds this sync stuff useful...)
Paul does true varispeed mean fully locked all the time, not wavering up and
 down to compensate for quantization in the sample rate values?

Once, I observed this wavering effect as a 'swishing' effect in SBLive cards
 when mixing an original signal with the output.
This was done at 44100Hz to turn on SBLive's (notorious?) always-on 
 conversions to 48000Hz.





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