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<p>Hi again,</p>
<p>I failed to say this... a benefit of using a PI-loop is that the
DC-component out of the ring-modulator is servo-steered to zero,
so no DC-blocking would be needed for the audio output part of the
loop once locked.</p>
<p>So, if one has a ring-mod one wants to dedicate to this, fairly
simple mods can be done. Just some care that not large DC-shifts
is not DC-blocked away. Unlocked the offset should be fairly close
to zero.<br>
</p>
<p>Cheers,<br>
Magnus<br>
</p>
<div class="moz-cite-prefix">On 2020-02-13 16:58, Magnus Danielson
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:9309283a-278e-df24-6a3e-b5cd2129f4dd@rubidium.se">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<p>Hi,<br>
</p>
<p>As you where doing BBD, and care about BBD output noise, why
not try to feed it a 1 kHz or better yet 3 kHz tone from a ...
you know... synthesizer. Then use another oscillator as
measurement lock-up oscillator, this one you want a DC-coupled
linear FM input if you can get it, but otherwise you have to go
with the normal CV input.</p>
<p>As phase-detector you can use a ring-modulator, but here you
want a DC output of the signal, which most does not do as they
have DC-blockers. You could use an XOR-gate if you have
square-waves into it.</p>
<p>Out of the phase-detector, you have two signal paths, one is
the loop filter for the PLL. Here I prefer to build a PI-loop,
which is essentially an integrator. The minimum build-up is an
op-amp with a input resistor and then a capacitor and resistor
in series in the negative feedback path. The minimum setup is
however a bit difficult to dimension things correctly on, as it
get good result when all the parameters is fixed so it's own
values can be fixed. A gain-pot may be needed to scale loop-gain
properly, that helps part of the PLL design problem. The second
path from the phase-detector should have a fixed gain stage
typically. So, a TL-072 with a handful of passives and a
XOR-gate of your choosing. Maybe another op-amp pair to square
signals up if needed.</p>
<p>Then, finally, a spectrum analyzer over the audio frequency
range. Nothing exotic, but good dynamics come into use. I would
maybe use a DN60 because it's lying around, but even the phone
with an app would work. If your oscilloscope can pull a FFT off,
fine.<br>
</p>
<p>If one can insert a signal from an offset oscillator (for a 1
kHz carrier signal, consider a 1,1 kHz tone to measure to
produce the 100 Hz offset) with a known relationship in
amplitude relative the carrier signal, say -30 dB, then one can
calibrate the scale for improved knowledge of noise levels, as
phase-noise is reported in dBc/sqrt(Hz), decibels relative
carrier, and corrected with the filter bandwidth.</p>
<p>It's not that this is very exotic things, it's just that since
you do not use these things like this, they may not be very well
prepared for it, so it's more that which causes you problems.
Some oscillators have PLL capability, I have a pair of JLC Moog
921 clones lying around, which has the PLL in them so it becomes
more the effort of pulling the right signal.</p>
<p>As you getto this, the cleanness of the oscillators etc. may
become a problem, but if you clearly can hear problems, then
maybe you have good enough stuff.</p>
<p>Phase-noise measurements like these isn't all that hard, and if
you work a little more with it, you will find slopes of noise as
well as spikes. The slopes is due to the white and flicker
noise, and as shaped by the resonator bandwidth, as modeled by
Dr. David Leeson in an article in Feb 1966. That and his 2016 50
year lookback is good reads, while just a scratch on the
surface. For long-term stability we use the time-stability
measure called Allan Deviation, of Dr. David Allan, as published
in the same Feb 1966 special issue. For Allan deviation, read
the Wikipedia article on Allan Variance, which I wrote.</p>
<p>One can home-brew quite sensitive phase-noise measurement tools
for very low cost, even for higher frequencies. I have a couple
of more extensive rigs that I use to measure high stability
quartz oscillators and atomic clocks. My basement lab grew
slightly out of hand from measure and perfect the ASM-1 VCOs,
which is where I started.<br>
</p>
<p>Cheers,<br>
Magnus<br>
</p>
<div class="moz-cite-prefix">On 2020-02-13 15:21, Tom Wiltshire
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:5695A29F-585E-46DF-9200-D31806E74704@electricdruid.net">
<meta http-equiv="Content-Type" content="text/html;
charset=UTF-8">
Thanks Magnus.
<div class=""><br class="">
</div>
<div class="">What’s the “ghetto” way of doing such a test?!</div>
<div class=""><br class="">
</div>
<div class="">I don’t have either a reference source of
frequencies that high (25-600KHz) or a spectrum analyser. The
scope does an FFT, but that’s as close as it gets. I don’t
even have a very accurate way to measure frequencies, much
less while they’re jumping about.</div>
<div class=""><br class="">
</div>
<div class="">Tom</div>
<div class=""><br class="">
<div class="">
<div style="word-wrap: break-word; -webkit-nbsp-mode: space;
-webkit-line-break: after-white-space;" class="">
<div style="color: rgb(0, 0, 0); font-family: Helvetica;
font-size: 12px; font-style: normal; font-variant-caps:
normal; font-weight: normal; letter-spacing: normal;
orphans: auto; text-align: start; text-indent: 0px;
text-transform: none; white-space: normal; widows: auto;
word-spacing: 0px; -webkit-text-stroke-width: 0px;">==================<br
class="">
Electric Druid<br class="">
Synth & Stompbox DIY<br class="">
==================</div>
</div>
</div>
<div><br class="">
<blockquote type="cite" class="">
<div class="">On 13 Feb 2020, at 14:15, Magnus Danielson
<<a href="mailto:magnus@rubidium.se" class=""
moz-do-not-send="true">magnus@rubidium.se</a>>
wrote:</div>
<br class="Apple-interchange-newline">
<div class="">
<meta http-equiv="Content-Type" content="text/html;
charset=UTF-8" class="">
<div class="">
<p class="">Hi,</p>
<p class="">The classical wow and flutter test is to
use a reference signal and then measure side-band
noise.</p>
<p class="">One way is to phase-lock an oscillator, as
the phase-lock locks up, the lock forces the output
of the phase-detector to produce side-band. Measure
the noise out of the phase-detector, preferably with
spectrum analyzer. With a separate oscillator being
inserted offset from the carrier, with known
amplitude and offset relative the carrier, the scale
can be calibrated.<br class="">
</p>
<p class="">Report noise amplitude in reference to the
amplitude of the carrier wave. This phase-noise
measurement is essentially what is described in IEEE
Std 1139.</p>
<p class="">Cheers,<br class="">
Magnus<br class="">
</p>
<div class="moz-cite-prefix">On 2020-02-11 13:06, Tom
Wiltshire wrote:<br class="">
</div>
<blockquote type="cite"
cite="mid:5123C853-5DF1-4B57-84D4-664DCA74BD1D@electricdruid.net"
class="">
<meta http-equiv="Content-Type" content="text/html;
charset=UTF-8" class="">
Hi All,
<div class=""><br class="">
</div>
<div class="">I thought I’d give you an update on
this.</div>
<div class=""><br class="">
</div>
<div class="">I’ve been able implement some of the
ideas you all provided, although it wasn’t
straightforward (is it ever?).</div>
<div class=""><br class="">
</div>
<div class="">Moving to the new chip allowed me to
double the NCO clock to 32MHz (idea 1). I also
doubled the frequency increment to use more
resolution in the NCO (idea2). This means that the
NCO output is four times higher than I need it, so
I then have to implement /4 somehow (idea 3).
Luckily there are two “Configurable Logic Cells”
on the chip that can be set up as divide-by-two
flip-flops. Unfortunately they don’t accept the
output from the NCO as an input, so I had to route
the NCO via another module (the “Digital Signal
Modulator”) set-up to pass the NCO straight
through. The final divided NCO output goes to the
“Complementary Waveform Generator” module that
makes the final biphase-output-with-deadband that
I need.</div>
<div class=""><br class="">
</div>
<div class="">In summary, the final “BBD Clock” uses
five different hardware modules on the 16F18313
chip! It looks like this:</div>
<div class=""> </div>
<div class="">NCO -> DSM -> CLC1 -> CLC2
-> CWG</div>
<div class=""><br class="">
</div>
<div class="">Ok, so in theory I should see some
improvement in performance. Now I come to my new
question! -</div>
<div class=""><br class="">
</div>
<div class="">How can I evaluate the performance of
this version against the old version?</div>
<div class=""><br class="">
</div>
<div class="">Currently the only real metric I have
is “does it sound noisy?” when it’s put in the
final circuit. This isn’t great since the noise
level depends very heavily on the exact
relationship between the frequency increment and
the NCO length, so it can vary markedly for quite
small changes.</div>
<div class=""><br class="">
</div>
<div class="">Thanks,</div>
<div class="">Tom</div>
<div class=""><br class="">
<div class="">
<div style="word-wrap: break-word;
-webkit-nbsp-mode: space; -webkit-line-break:
after-white-space;" class="">
<div style="font-family: Helvetica; font-size:
12px; font-style: normal; font-variant-caps:
normal; font-weight: normal; letter-spacing:
normal; text-align: start; text-indent: 0px;
text-transform: none; white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;" class="">==================<br
class="">
Electric Druid<br class="">
Synth & Stompbox DIY<br class="">
==================</div>
</div>
</div>
<div class=""><br class="">
<blockquote type="cite" class="">
<div class="">On 31 Jan 2020, at 12:07, Tom
Wiltshire <<a
href="mailto:tom@electricdruid.net"
class="" moz-do-not-send="true">tom@electricdruid.net</a>>
wrote:</div>
<br class="Apple-interchange-newline">
<div class="">
<meta http-equiv="Content-Type"
content="text/html; charset=UTF-8"
class="">
<div style="word-wrap: break-word;
-webkit-nbsp-mode: space; line-break:
after-white-space;" class="">Ok, so the
advice would be:
<div class=""><br class="">
</div>
<div class="">1) Use the highest NCO clock
I can to minimise jitter</div>
<div class="">2) Increase the frequency
increments as much as possible to use as
much of the available increment
resolution as I can</div>
<div class="">3) Divide the resulting
frequency down if it’s too much high</div>
<div class="">4) Add a little bit of
dither to break up audible cycles/tones</div>
<div class="">5) Sample the LFO at as high
a frequency as possible</div>
<div class=""><br class="">
</div>
<div class="">Is that a fair summary?
Anything I’ve missed? (Noise shaping the
dither, I suppose)</div>
<div class=""><br class="">
</div>
<div class="">For (1) I can move the clock
from 16MHz to 32MHz, so there’s a small
improvement.</div>
<div class="">For (2) we can increase the
frequency increment, assuming I can work
out a way to get the chip to provide the
division for (3). If I could run the NCO
at (say) x8 of the frequency I need,
that might offer some real benefit.</div>
<div class="">The dither (4) doesn’t
really depend on anything else, so that
should be do-able.</div>
<div class="">The LFO sample frequency
should also be able to increase since
the whole chip is running twice as fast
as the previous generation (32 vs 16MHz
again). So everything else being equal,
I might be able to up the LFO sample
rate to 50KHz or so. However, that seems
a bit crazy (audio-rate sampling for an
LFO with a max of 20Hz) and instead I
might do better to add some
interpolation of the frequency increment
at the end of each cycle. E.g. We’re
aiming for an increment of X, and we’ve
got an increment of Y, so next cycle
uses X+x to get a bit closer. The
difficulty there is that we need to know
how many NCO cycles there will be before
our next LFO sample, and that sounds
horribly like division! So maybe just
whacking the LFO sample rate up is in
fact the best you can do for that after
all.</div>
<div class=""><br class="">
</div>
<div class="">Thanks,</div>
<div class="">Tom</div>
<div class=""><br class="">
<div class="">
<div style="word-wrap: break-word;
-webkit-nbsp-mode: space;
-webkit-line-break:
after-white-space;" class="">
<div style="font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps: normal;
font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal; word-spacing:
0px; -webkit-text-stroke-width:
0px;" class="">==================<br
class="">
Electric Druid<br class="">
Synth & Stompbox DIY<br
class="">
==================</div>
</div>
</div>
<div class=""><br class="">
<blockquote type="cite" class="">
<div class="">On 28 Jan 2020, at
13:07, René Schmitz <<a
href="mailto:synth@schmitzbits.de"
class="" moz-do-not-send="true">synth@schmitzbits.de</a>>
wrote:</div>
<br
class="Apple-interchange-newline">
<div class=""><span
style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
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normal; font-variant-caps:
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0px; text-transform: none;
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none; display: inline
!important;" class="">Hi Richie,</span><br
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0); font-family: Helvetica;
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<br style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
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0px; text-transform: none;
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<span style="caret-color: rgb(0,
0, 0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
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text-align: start; text-indent:
0px; text-transform: none;
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word-spacing: 0px;
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text-decoration: none; float:
none; display: inline
!important;" class="">On
28.01.2020 13:23,<span
class="Apple-converted-space"> </span></span><a
href="mailto:rburnett@richieburnett.co.uk" style="font-family:
Helvetica; font-size: 12px;
font-style: normal;
font-variant-caps: normal;
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letter-spacing: normal; orphans:
auto; text-align: start;
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auto; word-spacing: 0px;
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class="" moz-do-not-send="true">rburnett@richieburnett.co.uk</a><span
style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
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none; display: inline
!important;" class=""><span
class="Apple-converted-space"> </span>wrote:</span><br
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0); font-family: Helvetica;
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text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
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text-decoration: none;" class="">
<span style="caret-color: rgb(0,
0, 0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none; float:
none; display: inline
!important;" class="">>>>
What I don’t understand though
is how this helps. Increasing
the</span><br
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0); font-family: Helvetica;
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<span style="caret-color: rgb(0,
0, 0); font-family: Helvetica;
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none; display: inline
!important;" class="">>>>
output frequency is going to
increase aliasing too, and
dividing it</span><br
style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
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<span style="caret-color: rgb(0,
0, 0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none; float:
none; display: inline
!important;" class="">>>>
down again afterwards doesn’t
seem to remove that to me. How
does</span><br
style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
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normal; font-variant-caps:
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text-align: start; text-indent:
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<span style="caret-color: rgb(0,
0, 0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
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0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
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text-decoration: none; float:
none; display: inline
!important;" class="">>>>
this work please, René?</span><br
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<span style="caret-color: rgb(0,
0, 0); font-family: Helvetica;
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text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
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text-decoration: none; float:
none; display: inline
!important;" class="">>></span><br
style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
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<span style="caret-color: rgb(0,
0, 0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
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white-space: normal;
word-spacing: 0px;
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text-decoration: none; float:
none; display: inline
!important;" class="">>>
It's a standard trick. With
higher DDS clock you get smaller</span><br
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<span style="caret-color: rgb(0,
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time-errors, and then the divide
down just removes transitions
between</span><br
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<span style="caret-color: rgb(0,
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the transitions. Higher
synthesized frequency allows you
to use more</span><br
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<span style="caret-color: rgb(0,
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none; display: inline
!important;" class="">>>
of the upper bits of the DDS, to
achieve more effective bits
useable</span><br
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<span style="caret-color: rgb(0,
0, 0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none; float:
none; display: inline
!important;" class="">>>
in the DDS.</span><br
style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none;" class="">
<span style="caret-color: rgb(0,
0, 0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none; float:
none; display: inline
!important;" class="">></span><br
style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none;" class="">
<span style="caret-color: rgb(0,
0, 0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none; float:
none; display: inline
!important;" class="">> Ok,
so this allows you to make
better use of the available DDS
frequency</span><br
style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none;" class="">
<span style="caret-color: rgb(0,
0, 0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none; float:
none; display: inline
!important;" class="">> bit
resolution, by synthesising a
higher output frequency and then</span><br
style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none;" class="">
<span style="caret-color: rgb(0,
0, 0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none; float:
none; display: inline
!important;" class="">>
dividing it down. But it
doesn't do anything to help with</span><br
style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none;" class="">
<span style="caret-color: rgb(0,
0, 0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none; float:
none; display: inline
!important;" class="">>
jitter/aliasing at the top end.</span><br
style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none;" class="">
<br style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none;" class="">
<span style="caret-color: rgb(0,
0, 0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none; float:
none; display: inline
!important;" class="">Here are
your original points:</span><br
style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none;" class="">
<span style="caret-color: rgb(0,
0, 0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none; float:
none; display: inline
!important;" class="">1)
Resampling of the LFO output by
the NCO reset</span><br
style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none;" class="">
<span style="caret-color: rgb(0,
0, 0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none; float:
none; display: inline
!important;" class="">2)
Frequency stepping caused by the
NCO minimum frequency step</span><br
style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none;" class="">
<span style="caret-color: rgb(0,
0, 0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none; float:
none; display: inline
!important;" class="">3) Jitter
cycles caused by the NCO</span><br
style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none;" class="">
<br style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none;" class="">
<span style="caret-color: rgb(0,
0, 0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none; float:
none; display: inline
!important;" class="">Well it
helps updating your NCO more
frequently, because each cycle
is shorter now. I.e. higher
sampling rate of your LFO.</span><br
style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none;" class="">
<br style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none;" class="">
<span style="caret-color: rgb(0,
0, 0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none; float:
none; display: inline
!important;" class="">The NCOs
minimum frequency step is
reduced. Because the tuning word
effectively shifts right,
bringing in room for more LSBs.</span><br
style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none;" class="">
<br style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none;" class="">
<span style="caret-color: rgb(0,
0, 0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none; float:
none; display: inline
!important;" class="">The cycle
to cycle time variation (aka
jitter) is still 1/f(clock) of
your NCO. Not really an
improvement there by the
division, if you run the NCO at
the same frequency as before.
But if you can run the NCO clock
higher then the variation is
reduced.</span><br
style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none;" class="">
<br style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none;" class="">
<span style="caret-color: rgb(0,
0, 0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none; float:
none; display: inline
!important;" class="">Best,</span><br
style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none;" class="">
<span style="caret-color: rgb(0,
0, 0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none; float:
none; display: inline
!important;" class="">René</span><br
style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none;" class="">
<br style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none;" class="">
<span style="caret-color: rgb(0,
0, 0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none; float:
none; display: inline
!important;" class="">--</span><br
style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none;" class="">
<a
href="mailto:synth@schmitzbits.de"
style="font-family: Helvetica;
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normal; font-variant-caps:
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letter-spacing: normal; orphans:
auto; text-align: start;
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text-transform: none;
white-space: normal; widows:
auto; word-spacing: 0px;
-webkit-text-size-adjust: auto;
-webkit-text-stroke-width: 0px;"
class="" moz-do-not-send="true">synth@schmitzbits.de</a><br
style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
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<a href="http://schmitzbits.de/"
style="font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal; orphans:
auto; text-align: start;
text-indent: 0px;
text-transform: none;
white-space: normal; widows:
auto; word-spacing: 0px;
-webkit-text-size-adjust: auto;
-webkit-text-stroke-width: 0px;"
class="" moz-do-not-send="true">http://schmitzbits.de</a><br
style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none;" class="">
<span style="caret-color: rgb(0,
0, 0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none; float:
none; display: inline
!important;" class="">_______________________________________________</span><br
style="caret-color: rgb(0, 0,
0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none;" class="">
<span style="caret-color: rgb(0,
0, 0); font-family: Helvetica;
font-size: 12px; font-style:
normal; font-variant-caps:
normal; font-weight: normal;
letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
white-space: normal;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;
text-decoration: none; float:
none; display: inline
!important;" class="">Synth-diy
mailing list</span><br
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letter-spacing: normal;
text-align: start; text-indent:
0px; text-transform: none;
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word-spacing: 0px;
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text-decoration: none;" class="">
<a
href="mailto:Synth-diy@synth-diy.org"
style="font-family: Helvetica;
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class="" moz-do-not-send="true">Synth-diy@synth-diy.org</a><br
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class="" moz-do-not-send="true">http://synth-diy.org/mailman/listinfo/synth-diy</a></div>
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<br class="">
</div>
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_______________________________________________<br class="">
Synth-diy mailing list<br class="">
<a href="mailto:Synth-diy@synth-diy.org"
class="" moz-do-not-send="true">Synth-diy@synth-diy.org</a><br
class="">
<a class="moz-txt-link-freetext"
href="http://synth-diy.org/mailman/listinfo/synth-diy"
moz-do-not-send="true">http://synth-diy.org/mailman/listinfo/synth-diy</a><br
class="">
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</blockquote>
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<br class="">
</div>
<br class="">
<fieldset class="mimeAttachmentHeader"></fieldset>
<pre class="moz-quote-pre" wrap="">_______________________________________________
Synth-diy mailing list
<a class="moz-txt-link-abbreviated" href="mailto:Synth-diy@synth-diy.org" moz-do-not-send="true">Synth-diy@synth-diy.org</a>
<a class="moz-txt-link-freetext" href="http://synth-diy.org/mailman/listinfo/synth-diy" moz-do-not-send="true">http://synth-diy.org/mailman/listinfo/synth-diy</a>
</pre>
</blockquote>
</div>
_______________________________________________<br
class="">
Synth-diy mailing list<br class="">
<a href="mailto:Synth-diy@synth-diy.org" class=""
moz-do-not-send="true">Synth-diy@synth-diy.org</a><br
class="">
<a class="moz-txt-link-freetext"
href="http://synth-diy.org/mailman/listinfo/synth-diy"
moz-do-not-send="true">http://synth-diy.org/mailman/listinfo/synth-diy</a><br
class="">
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</blockquote>
</div>
<br class="">
</div>
</blockquote>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<pre class="moz-quote-pre" wrap="">_______________________________________________
Synth-diy mailing list
<a class="moz-txt-link-abbreviated" href="mailto:Synth-diy@synth-diy.org">Synth-diy@synth-diy.org</a>
<a class="moz-txt-link-freetext" href="http://synth-diy.org/mailman/listinfo/synth-diy">http://synth-diy.org/mailman/listinfo/synth-diy</a>
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