4046 PLL model scarcity.

Lostgallifreyan wrote:
Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote in
news:r05ja71nclq42d4hj387uqlun8b3vnngpo@4ax.com:


? Is it really that useful?



For interesting uses in making electronic music, yes. And perhaps any time a
fast cheap oscillator is wanted. IF the VCO is linear... Again, I point out
that page I linked to:
http://www.birthofasynth.com/Thomas_Henry/Pages/X-4046.html

I thought about using one that way (until I decided that getting a
pitch-based voltage to put into Dieter Doepfer's R2M 'ribbon control' unit
was more than enough for me), and that page shows at least two people
actually did it. Looks like a mighty useful IC to me... Most of the BIG
innovators of VCO's for music making would blush when confronted with specs
like those guys came up with using a 4046. Only the VCO's on the big famous
modular machines even came close.
Those wave forms have noise on the peak of each one! Looks like they
Click to expand...
took measurements possibly using a 1:1 probe or, that circuit just is
crappie!

Jamie
 
On Oct 27, 6:22 pm, Lostgallifreyan <no-...@nowhere.net> wrote:
Phil Hobbs <pcdhSpamMeSensel...@electrooptical.net> wrote innews:4EA8A469..2040204@electrooptical.net:

The metal gate parts are very nice, except for the dead zone in the
phase detector.

The HC parts are far more nonlinear--more like 3:1 in slope, if not
worse, and with VDD = 5V, they crap out at 1 to 1.3 V--they just stop
oscillating.  We had a thread about this back in July--see
http://groups.google.com/group/sci.electronics.design/msg/528c22e578d...

Thanks, that's interesting. Can you tell me more about that resistor that
helps the dead zone problem (which I also don't understand yet)? Is it
loading the output to ground?
Click to expand...
The NXP 74HC9046 doesn't have the dead-zone problem on the digital
phase-comparator (PC2) and page 8 of the data sheet spells out the
problem with the original 4046, and the solution implelmented on the
74HC9046

http://ics.nxp.com/products/hc/datasheet/74hct9046a.pdf

The voltage-controlled oscillator isn't wildly attractive, but at
least the problems with it are spelled out.

You can buy them in small quantities, but not from Farnell

http://search.digikey.com/scripts/DkSearch/dksus.dll?vendor=0&keywords=74HCT9046

http://www.futureelectronics.com/en/Technologies/Product.aspx?ProductID=74HCT9046APWNXP7585573

--
Bill Sloman, Nijmegen
 
Jamie <jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote in
news:JXkqq.3431$yY3.2765@newsfe01.iad:

I thought about using one that way (until I decided that getting a
pitch-based voltage to put into Dieter Doepfer's R2M 'ribbon control'
unit was more than enough for me), and that page shows at least two
people actually did it. Looks like a mighty useful IC to me... Most of
the BIG innovators of VCO's for music making would blush when
confronted with specs like those guys came up with using a 4046. Only
the VCO's on the big famous modular machines even came close.

Those wave forms have noise on the peak of each one! Looks like they
took measurements possibly using a 1:1 probe or, that circuit just is
crappie!
Click to expand...
The kind of 'noise' that a 1 pole passive LPF (RC integrator) ought to fix.
Or a simple clipper, given that the amplitide would be cosnatnt with
frequency. Given that a synthesiser normally uses a 4 pole LPF I doubt they
considered that noise important. Analog synth waveforms vary a LOT more than
theirs do, you should see some of the 'sawtooths' out there! What you saw is
well behaved in comparison.
 
Jamie <jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote in
news:JXkqq.3431$yY3.2765@newsfe01.iad:

Those wave forms have noise on the peak of each one! Looks like they
took measurements possibly using a 1:1 probe or, that circuit just is
crappie!
Click to expand...
Just for the proverbial shits and giggles, take a look at the 'analog'
sawtooth emulations in Yamaha's AN1X synthesiser! >:) If you have one
conveniently placed... I got better than that based on Yamaha's own, the
SY99, using FM synthesis, I got wave shapes that looked and sounded like the
Prophet 5! Even got them scaling correctly over several octaves without
distortion or aliasing, something even Yamaha failed to do with their own
tech, for reasons I can't understand, given that I could do it with front
panel controls. Three of those waveforms in a single voice got me a
well-priced sale of my first SY99, to a guy who owned Minimoogs. He was
totally convinced. That whole experience led me to buy an SY99 again some
years later, and I still have it. BUT, the AN1X sold a lot more machines for
Yamaha, it's extremely popular in the rave scene. Lesson learned: people will
accept some REALLY crappy waveforms if they like the noise they make. Those
PLL-based waves are some of the better ones, by far.
 
Bill Sloman <bill.sloman@ieee.org> wrote in news:bdbc6f2e-3be2-4278-b1a4-
d6f358901227@s11g2000yqi.googlegroups.com:

The NXP 74HC9046 doesn't have the dead-zone problem on the digital
phase-comparator (PC2) and page 8 of the data sheet spells out the
problem with the original 4046, and the solution implelmented on the
74HC9046

http://ics.nxp.com/products/hc/datasheet/74hct9046a.pdf

The voltage-controlled oscillator isn't wildly attractive, but at
least the problems with it are spelled out.
Click to expand...
Thanks, that's useful to me. I might try one, if the HEF4046B VCO doesn't
work well enough. One thing I saw, though not for certain as the graph for
linearity at a few hundred KHz covers less than two octaves worth, is that
linearity may be better at a few hundred KHz rather than audio frequencies.
If the same is true for the HEF4046B I might try a scheme I already
considered, using some division in the loop to get HF output from AF input,
as I only need the voltage, and can scale and offset later. If this can speed
response to bass frequency inputs (something I'm also still uncertain of),
then I'd definitely do this.
 
On Oct 27, 6:22 pm, Lostgallifreyan <no-...@nowhere.net> wrote:
Phil Hobbs <pcdhSpamMeSensel...@electrooptical.net> wrote innews:4EA8A469..2040204@electrooptical.net:

The metal gate parts are very nice, except for the dead zone in the
phase detector.

The HC parts are far more nonlinear--more like 3:1 in slope, if not
worse, and with VDD = 5V, they crap out at 1 to 1.3 V--they just stop
oscillating.  We had a thread about this back in July--see
http://groups.google.com/group/sci.electronics.design/msg/528c22e578d...

Thanks, that's interesting. Can you tell me more about that resistor that
helps the dead zone problem (which I also don't understand yet)? Is it
loading the output to ground?
Click to expand...
Check out the NXP 74HCT9046 which incorporates a solution to the dead
zone problem

http://www.nxp.com/documents/data_sheet/74HCT9046A.pdf

which is discussed on page 8 of the data sheet.

--
Bill sloman, Nijmegen
 
Hello. Did you see my reply last night? More posts from you suggest you may
not have, and that you weren't seeing your own posts getting through either.
In case you see this, here's the reply from last night:

Thanks, that's useful to me. I might try one, if the HEF4046B VCO doesn't
work well enough. One thing I saw, though not for certain as the graph for
linearity at a few hundred KHz covers less than two octaves worth, is that
linearity may be better at a few hundred KHz rather than audio frequencies.
If the same is true for the HEF4046B I might try a scheme I already
considered, using some division in the loop to get HF output from AF input,
as I only need the voltage, and can scale and offset later. If this can speed
response to bass frequency inputs (something I'm also still uncertain of),
then I'd definitely do this.


Bill Sloman <bill.sloman@ieee.org> wrote in news:ad5d8b0f-521d-4186-ab5b-
5abd6560e531@h24g2000yqm.googlegroups.com:

On Oct 27, 6:22 pm, Lostgallifreyan <no-...@nowhere.net> wrote:
Phil Hobbs <pcdhSpamMeSensel...@electrooptical.net> wrote innews:4EA8A469
.2040204@electrooptical.net:

The metal gate parts are very nice, except for the dead zone in the
phase detector.

The HC parts are far more nonlinear--more like 3:1 in slope, if not
worse, and with VDD = 5V, they crap out at 1 to 1.3 V--they just stop
oscillating.  We had a thread about this back in July--see
http://groups.google.com/group/sci.electronics.design/msg/528c22e578d...

Thanks, that's interesting. Can you tell me more about that resistor that
helps the dead zone problem (which I also don't understand yet)? Is it
loading the output to ground?

For the dead zone problem, see the NXP 74HCT9046 which is claimed not
to have it, and discusses the questtion in some detail on page 8 of
its data sheet.

http://ics.nxp.com/products/hc/datasheet/74hct9046a.pdf

The data sheet does include detail on the VCO frequency to voltage
relationship.

--
Bill Sloman, Nijmegen
Click to expand...
 
On Oct 27, 6:22 pm, Lostgallifreyan <no-...@nowhere.net> wrote:
Phil Hobbs <pcdhSpamMeSensel...@electrooptical.net> wrote innews:4EA8A469..2040204@electrooptical.net:

The metal gate parts are very nice, except for the dead zone in the
phase detector.

The HC parts are far more nonlinear--more like 3:1 in slope, if not
worse, and with VDD = 5V, they crap out at 1 to 1.3 V--they just stop
oscillating.  We had a thread about this back in July--see
http://groups.google.com/group/sci.electronics.design/msg/528c22e578d...

Thanks, that's interesting. Can you tell me more about that resistor that
helps the dead zone problem (which I also don't understand yet)? Is it
loading the output to ground?
Click to expand...
For the dead zone problem, see the NXP 74HCT9046 which is claimed not
to have it, and discusses the questtion in some detail on page 8 of
its data sheet.

http://ics.nxp.com/products/hc/datasheet/74hct9046a.pdf

The data sheet does include detail on the VCO frequency to voltage
relationship.

--
Bill Sloman, Nijmegen
 
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