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<div class="moz-cite-prefix">Am 15.03.2017 um 17:13 schrieb Bruno
Afonso:<br>
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cite="mid:CA+z2k4u76eDpP7Xi6T7DHWC5PML20N66Bshf0d8zbV1U34Fjww@mail.gmail.com"
type="cite">
<div dir="ltr">3) you mention jitter several times but there is no
statistical description of the phenomena (mean, std dev, etc) or
even a graphic depiction such as an histogram. Without this it's
hard for the reader to see how relevant it may or not be. <br>
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I calculated the standard deviation and mean value for the delay
between the tempo clock and the gate signal and added a nice diagram
to the PDF. I also added some diagrams showing the total on and off
times for the gate signal at 2 different speeds.
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<div>Personally, I feel it would be cool to simulate the clock
interplay to reproduce obseved experimental data and then
explore the space in order to get it more tight or more loose.
Would it have a big impact on sound and experience? Would
people care or notice if they used a much tighter 303 clock
wise?</div>
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While I'm at it and have all the hardware here I could set up some
A/B testing audio files. Do you think it would be worth the hassle?
<br>
<br>
I have a 303 with a socket for the CPU and not yet returned my
loaned original Roland CPU.<br>
Further I currently have a Quicksilver CPU here that has a much
tighter timing (measured the tempo clock to gate on/off delay to be
in the 0.1ms to 0.35ms range) and of course my own CPU with the
emulated timing like in the original, but I could easily make it
switchable that a button press would turn off the fixed 1ms/2.4ms
interrupt gate latency and probably change the 1.8ms polling
interrupt to a pin change triggered interrupt to follow the tempo
clock tightly. But I guess the QS timing should be tight enough <br>
<br>
So I could record a few patterns with different CPUs in the same
synth hardware to exclude influences by differences in the analogue
part of the machine or different knob settings.<br>
<br>
Would be interesting to find out<br>
A) If people can hear the difference between original sequencer,
emulated sequencer and a tight sequencer<br>
B) What listeners prefer if they are able to distinguish it.<br>
<br>
maybe even add a 4th audio example to the test where the jitter and
latencies are increased slightly?<br>
<br>
cheers,<br>
Julian<br>
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<div>cheers</div>
<div>b</div>
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<div class="gmail_quote">
<div dir="ltr">On Wed, Mar 15, 2017 at 11:14 AM Julian Schmidt
<<a moz-do-not-send="true" href="mailto:elfenjunge@gmx.net">elfenjunge@gmx.net</a>>
wrote:<br>
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<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">I'm
currently working on a TB-303 replacement CPU for the RE-303
project.<br class="gmail_msg">
www.<a moz-do-not-send="true"
href="http://sonic-potions.com/re303" rel="noreferrer"
class="gmail_msg" target="_blank">http://sonic-potions.com/re303</a><br
class="gmail_msg">
<br class="gmail_msg">
Since there is not too much information available, and a lot
of<br class="gmail_msg">
speculations are running wild on the net, I tried to clear
things up a bit.<br class="gmail_msg">
<br class="gmail_msg">
Someone from the RE-303 forums loaned me an original CPU and I
hooked it<br class="gmail_msg">
up to a logic analyzer and did some extensive testing and
measurement<br class="gmail_msg">
sessions.<br class="gmail_msg">
<br class="gmail_msg">
I summed up my findings in a short paper available here:<br
class="gmail_msg">
<a moz-do-not-send="true"
href="http://sonic-potions.com/Documentation/Analysis_of_the_D650C-133_CPU_timing.pdf"
rel="noreferrer" class="gmail_msg" target="_blank">http://sonic-potions.com/Documentation/Analysis_of_the_D650C-133_CPU_timing.pdf</a><br
class="gmail_msg">
<br class="gmail_msg">
I have to admit, a lot of it is definitely from the "hear the
fleas<br class="gmail_msg">
cough" category, as we say in Germany, but at least we now
have data<br class="gmail_msg">
coming from a real CPU.<br class="gmail_msg">
<br class="gmail_msg">
Comments are welcome. I'm a bit rusty in writing proper papers
;)<br class="gmail_msg">
<br class="gmail_msg">
Best,<br class="gmail_msg">
Julian<br class="gmail_msg">
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