<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body>
<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; 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="">Hi Richie,</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="">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;
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">rburnett@richieburnett.co.uk</a><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
class="Apple-converted-space"> </span>wrote:</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="">>>> What I don’t
understand though is how this
helps. Increasing the</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="">>>> output
frequency is going to increase
aliasing too, and dividing it</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="">>>> 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; 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="">>>> this work
please, 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="">
<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="">>> It's a standard
trick. With higher DDS clock you
get smaller</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="">>> time-errors, and
then the divide down just removes
transitions between</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="">>> the transitions.
Higher synthesized frequency
allows you to use more</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="">>> of the upper
bits of the DDS, to achieve more
effective bits useable</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="">>> 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;
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">synth@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="">
<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
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-diy@synth-diy.org"
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">Synth-diy@synth-diy.org</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="">
<a
href="http://synth-diy.org/mailman/listinfo/synth-diy"
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://synth-diy.org/mailman/listinfo/synth-diy</a></div>
</blockquote>
</div>
<br class="">
</div>
</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="">
</div>
</blockquote>
</div>
<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">http://synth-diy.org/mailman/listinfo/synth-diy</a><br
class="">
</div>
</blockquote>
</div>
<br class="">
</div>
</blockquote>
</body>
</html>