## SSF zero point oscilator

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Artaos
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### Re: SSF zero point oscilator

Question about the ZPO: can it do TZ FM without doing AM of the resulting waveform at the same time? For example: TZ-MOD set to Linear, a modulator into Linear FM input, ZP-INDEX knob at zero, no ZP modulator.
Based on what I understand so far in this discussion, it seems that a rectified version of the modulator would be applied to the core frequency, and that a non-rectified version would be applied to ZP (i.e. doing four quadrant multiplication or ring modulation between the modulator and the ZPO waveform). TZFM suggests a rectified frequency modulator, and a reversal of the waveform, not full amplitude modulation of the waveform. Can the ZPO do that?

ari ellis
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### Re: SSF zero point oscilator

Artaos wrote:
Fri Jan 03, 2020 3:18 pm
Question about the ZPO: can it do TZ FM without doing AM of the resulting waveform at the same time? For example: TZ-MOD set to Linear, a modulator into Linear FM input, ZP-INDEX knob at zero, no ZP modulator.
Based on what I understand so far in this discussion, it seems that a rectified version of the modulator would be applied to the core frequency, and that a non-rectified version would be applied to ZP (i.e. doing four quadrant multiplication or ring modulation between the modulator and the ZPO waveform). TZFM suggests a rectified frequency modulator, and a reversal of the waveform, not full amplitude modulation of the waveform. Can the ZPO do that?
From my bystander's vantage point I would think not quite, since my understanding is that if the TZ-MOD is set such that the incoming modulator is rectified, the modulator also gets sent to the through-zero VCA, and that this is how the reversal of the waveform is accomplished. But analogPedagog might have something to say here.

All this said, I would also think that the difference between pure reversal and ring modulation would be pretty minimal... And probably not musically important. If you used a square wave modulator there would presumably be no meaningful difference at all?

EDIT: It's even better than that. analogPedagog explains below how a nonlinear TZVCA design makes the polarity reversal on the ZPO closer to pure polarity reversal than an ordinary ring mod would be.
Last edited by ari ellis on Fri Jan 03, 2020 4:30 pm, edited 1 time in total.

johannes
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### Re: SSF zero point oscilator

after reading this thread i would like to hear more zpo sounds. but it seems there is not much audio online ... at least on soundcloud
or did i miss something?

analogPedagog
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### Re: SSF zero point oscilator

Artaos wrote:
Fri Jan 03, 2020 3:18 pm
Question about the ZPO: can it do TZ FM without doing AM of the resulting waveform at the same time? For example: TZ-MOD set to Linear, a modulator into Linear FM input, ZP-INDEX knob at zero, no ZP modulator.
Based on what I understand so far in this discussion, it seems that a rectified version of the modulator would be applied to the core frequency, and that a non-rectified version would be applied to ZP (i.e. doing four quadrant multiplication or ring modulation between the modulator and the ZPO waveform). TZFM suggests a rectified frequency modulator, and a reversal of the waveform, not full amplitude modulation of the waveform. Can the ZPO do that?
There is no TZFM without a waveform reversal, but if you wanted just the FM component, you can set ZP all the way CW/CCW and only the slightest effect may occur, depending on the amplitude of the modulation. No extra ZP modulator is needed when an FM input is set to TZ-MOD.

Maybe it wasn't clear in some of the discussions, but the 4-quandrant multiplier is not linear, and operates very quickly at the zero crossing performing the waveform reversal. What you describe as full amplitude modulation is occurring much more quickly than a standard amplitude modulator.

So what is happening is not the same as using a normal TZVCA - I think this is an important point and may be what is central to your question?

I know I have been pretty open on how the ZPO works, but in case it isn't known, some already past/present designs have used a switch, or manage current flow into the VCO core, among others. I wouldn't be surprised if I am not the first to use a VCA to accomplish this. Point is, there are a number of techniques that have been used to manage this function in an analog implementation. This is simply one more with the extra feature of decoupling the two major TZFM components

analogPedagog
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### Re: SSF zero point oscilator

johannes wrote:
Fri Jan 03, 2020 3:45 pm
after reading this thread i would like to hear more zpo sounds. but it seems there is not much audio online ... at least on soundcloud
or did i miss something?

Here is an audio demo for Linear TZFM, using sine waves only for both the carrier and modulator. Went pretty random on this one to try and cover a lot of frequencies of both the ZPO and the modulation source.

There is some dynamic FM in there involving using an envelope into Zero Point. An ADSRVCA is used for the ZPO sine output and the same envelope is used to modulate Zero point.

More to come;

muffdiver
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### Re: SSF zero point oscilator

This was my first patch with ZPO:

---,---,---,---,---,---,---,---,---,---,---,---,---,---,---,---,

---`---`---`---`---`---`---`---`---`---`---`---`---`---`

ari ellis
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### Re: SSF zero point oscilator

muffdiver wrote:
Fri Jan 03, 2020 6:33 pm
This was my first patch with ZPO:

Awesome sounds bud!

brandonlogic
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### Re: SSF zero point oscilator

analogPedagog wrote:
Fri Jan 03, 2020 5:36 pm
johannes wrote:
Fri Jan 03, 2020 3:45 pm
after reading this thread i would like to hear more zpo sounds. but it seems there is not much audio online ... at least on soundcloud
or did i miss something?

Here is an audio demo for Linear TZFM, using sine waves only for both the carrier and modulator. Went pretty random on this one to try and cover a lot of frequencies of both the ZPO and the modulation source.

There is some dynamic FM in there involving using an envelope into Zero Point. An ADSRVCA is used for the ZPO sine output and the same envelope is used to modulate Zero point.

More to come;

Thanks! I was looking forward to hearing a demo with only sines. Sounds good! Although it sounds quite different then most sine wave fm I’ve used, like the super smooth doepfer 110-4’s or rubicon for example. It sounds a bit more rough, like there’s some extra harmonics going on, more so than what you typically get with analog sine carrier and modulator, especially towards the end. Is that a result of how fm is implemented?

analogPedagog
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### Re: SSF zero point oscilator

brandonlogic wrote:
Fri Jan 03, 2020 7:02 pm
analogPedagog wrote:
Fri Jan 03, 2020 5:36 pm
johannes wrote:
Fri Jan 03, 2020 3:45 pm
after reading this thread i would like to hear more zpo sounds. but it seems there is not much audio online ... at least on soundcloud
or did i miss something?

Here is an audio demo for Linear TZFM, using sine waves only for both the carrier and modulator. Went pretty random on this one to try and cover a lot of frequencies of both the ZPO and the modulation source.

There is some dynamic FM in there involving using an envelope into Zero Point. An ADSRVCA is used for the ZPO sine output and the same envelope is used to modulate Zero point.

More to come;

Thanks! I was looking forward to hearing a demo with only sines. Sounds good! Although it sounds quite different then most sine wave fm I’ve used, like the super smooth doepfer 110-4’s or rubicon for example. It sounds a bit more rough, like there’s some extra harmonics going on, more so than what you typically get with analog sine carrier and modulator, especially towards the end. Is that a result of how fm is implemented?
It is a bit stronger due to the implementation, but I am also using a very fast attack time on the envelope to modulate zero point.

But specifically, since the ZP is not attenuated while the FM is, the effect is stronger. If I could jam it in there, I would have added an overall FM+ZP VCA attenuator. So to achieve the more familiar softer tones, you would need to process the modulator through an attenuator or VCA before going into the ZPO while using TZFM. I can whip up a demo of that soon if you like.

brandonlogic
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### Re: SSF zero point oscilator

analogPedagog wrote:
Fri Jan 03, 2020 7:47 pm
brandonlogic wrote:
Fri Jan 03, 2020 7:02 pm
analogPedagog wrote:
Fri Jan 03, 2020 5:36 pm
johannes wrote:
Fri Jan 03, 2020 3:45 pm
after reading this thread i would like to hear more zpo sounds. but it seems there is not much audio online ... at least on soundcloud
or did i miss something?

Here is an audio demo for Linear TZFM, using sine waves only for both the carrier and modulator. Went pretty random on this one to try and cover a lot of frequencies of both the ZPO and the modulation source.

There is some dynamic FM in there involving using an envelope into Zero Point. An ADSRVCA is used for the ZPO sine output and the same envelope is used to modulate Zero point.

More to come;

Thanks! I was looking forward to hearing a demo with only sines. Sounds good! Although it sounds quite different then most sine wave fm I’ve used, like the super smooth doepfer 110-4’s or rubicon for example. It sounds a bit more rough, like there’s some extra harmonics going on, more so than what you typically get with analog sine carrier and modulator, especially towards the end. Is that a result of how fm is implemented?
It is a bit stronger due to the implementation, but I am also using a very fast attack time on the envelope to modulate zero point.

But specifically, since the ZP is not attenuated while the FM is, the effect is stronger. If I could jam it in there, I would have added an overall FM+ZP VCA attenuator. So to achieve the more familiar softer tones, you would need to process the modulator through an attenuator or VCA before going into the ZPO while using TZFM. I can whip up a demo of that soon if you like.
Thanks for the explanation! yeah I’d be interested to hear, if you have time sometime.

comacomfort
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### Re: SSF zero point oscilator

analogPedagog wrote:
Fri Jan 03, 2020 5:36 pm
johannes wrote:
Fri Jan 03, 2020 3:45 pm
after reading this thread i would like to hear more zpo sounds. but it seems there is not much audio online ... at least on soundcloud
or did i miss something?

Here is an audio demo for Linear TZFM, using sine waves only for both the carrier and modulator. Went pretty random on this one to try and cover a lot of frequencies of both the ZPO and the modulation source.

There is some dynamic FM in there involving using an envelope into Zero Point. An ADSRVCA is used for the ZPO sine output and the same envelope is used to modulate Zero point.

More to come;

Hmm, also you need to do a demo routing a Full drum voice (or drum samples) into the TZFM input, it makes for a really interesting distortion, waveshaper, i played with it a bit and loved the wild sounds, but i don't have time right now to make demos, i'm surprised nobody routes much content other than oscillators into oscillators.

Even routing a granular synth into it would probably get interesting results.

analogPedagog
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### Re: SSF zero point oscilator

Had a few minutes to spare so here's round 2 of the SINE mods SINE demos.

This is a very similar patch but now with the modulator first going through a passive attenuator. The envelope is again applied to Zero Point and is removed at roughly the 4:20 mark.

Random tunings here, perhaps got a little handy with the frequency but I think you will get the point. Various levels with the attenuator as well as offsetting ZP manually.

Artaos
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### Re: SSF zero point oscilator

analogPedagog wrote:
Fri Jan 03, 2020 4:04 pm
Artaos wrote:
Fri Jan 03, 2020 3:18 pm
Question about the ZPO: can it do TZ FM without doing AM of the resulting waveform at the same time? For example: TZ-MOD set to Linear, a modulator into Linear FM input, ZP-INDEX knob at zero, no ZP modulator.
Based on what I understand so far in this discussion, it seems that a rectified version of the modulator would be applied to the core frequency, and that a non-rectified version would be applied to ZP (i.e. doing four quadrant multiplication or ring modulation between the modulator and the ZPO waveform). TZFM suggests a rectified frequency modulator, and a reversal of the waveform, not full amplitude modulation of the waveform. Can the ZPO do that?
There is no TZFM without a waveform reversal, but if you wanted just the FM component, you can set ZP all the way CW/CCW and only the slightest effect may occur, depending on the amplitude of the modulation. No extra ZP modulator is needed when an FM input is set to TZ-MOD.

Maybe it wasn't clear in some of the discussions, but the 4-quandrant multiplier is not linear, and operates very quickly at the zero crossing performing the waveform reversal. What you describe as full amplitude modulation is occurring much more quickly than a standard amplitude modulator.

So what is happening is not the same as using a normal TZVCA - I think this is an important point and may be what is central to your question?

I know I have been pretty open on how the ZPO works, but in case it isn't known, some already past/present designs have used a switch, or manage current flow into the VCO core, among others. I wouldn't be surprised if I am not the first to use a VCA to accomplish this. Point is, there are a number of techniques that have been used to manage this function in an analog implementation. This is simply one more with the extra feature of decoupling the two major TZFM components
Thank you for your answer. Yes, I think I am confused about how/why the ZP VCA affects the waveform. Let’s take an example of a sine carrier and a sine modulator, to help me understand, at a time t where carrier is +5V and modulator is 0V. (And there is no FM index.) With TZFM, since frequency modulator is 0, frequency should be 0Hz, i.e. the oscillator core should be stopped and the +5V output should be held constant. However if we introduce four-quadrant multiplication (as I understand ZP to be), then the output would be multiplied by 0, meaning output = 0V. So it seems to me that the waveforms are different?

analogPedagog
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### Re: SSF zero point oscilator

Artaos wrote:
Fri Jan 03, 2020 9:31 pm
analogPedagog wrote:
Fri Jan 03, 2020 4:04 pm
Artaos wrote:
Fri Jan 03, 2020 3:18 pm
Question about the ZPO: can it do TZ FM without doing AM of the resulting waveform at the same time? For example: TZ-MOD set to Linear, a modulator into Linear FM input, ZP-INDEX knob at zero, no ZP modulator.
Based on what I understand so far in this discussion, it seems that a rectified version of the modulator would be applied to the core frequency, and that a non-rectified version would be applied to ZP (i.e. doing four quadrant multiplication or ring modulation between the modulator and the ZPO waveform). TZFM suggests a rectified frequency modulator, and a reversal of the waveform, not full amplitude modulation of the waveform. Can the ZPO do that?
There is no TZFM without a waveform reversal, but if you wanted just the FM component, you can set ZP all the way CW/CCW and only the slightest effect may occur, depending on the amplitude of the modulation. No extra ZP modulator is needed when an FM input is set to TZ-MOD.

Maybe it wasn't clear in some of the discussions, but the 4-quandrant multiplier is not linear, and operates very quickly at the zero crossing performing the waveform reversal. What you describe as full amplitude modulation is occurring much more quickly than a standard amplitude modulator.

So what is happening is not the same as using a normal TZVCA - I think this is an important point and may be what is central to your question?

I know I have been pretty open on how the ZPO works, but in case it isn't known, some already past/present designs have used a switch, or manage current flow into the VCO core, among others. I wouldn't be surprised if I am not the first to use a VCA to accomplish this. Point is, there are a number of techniques that have been used to manage this function in an analog implementation. This is simply one more with the extra feature of decoupling the two major TZFM components
Thank you for your answer. Yes, I think I am confused about how/why the ZP VCA affects the waveform. Let’s take an example of a sine carrier and a sine modulator, to help me understand, at a time t where carrier is +5V and modulator is 0V. (And there is no FM index.) With TZFM, since frequency modulator is 0, frequency should be 0Hz, i.e. the oscillator core should be stopped and the +5V output should be held constant. However if we introduce four-quadrant multiplication (as I understand ZP to be), then the output would be multiplied by 0, meaning output = 0V. So it seems to me that the waveforms are different?
So what you are asking is really just analogous to having nothing patched into any FM inputs and setting ZP dead center, in which case frequency = 0, output is completely null. So you are correct about the output becoming 0V, which is also constant.

This will the case with the exception of the SAW and RIPSAW, which are effected by the wave shaper circuitry and will produce a half amplitude pulse and multi-pulse, respectively.

There are ZERO TZVCOs out there that can actually be brought down to 0Hz via FM. Maybe you could get close if the OSC was set low enough but this is not what happens in an analog TZVCO as far as frequency modulation goes.
The effect and I stress effect of falling down to 0Hz is accomplished by reversing the current flow into the VCO core (traditionally).
So in other words, this effect of reaching 0Hz is an extremely fast transient state occurring at whatever point in the wave cycle that the reversal is initiated (traditionally a perfect implementation is supposed to flip near the waveform peak). The non-linear TZVCA in the ZPO behaves in a very similar manner, for that same brief amount of time, the frequency is absolutely zero. The difference on the ZPO is that the reversing nominally occurs around 0V and if you happened to be able to stop it exactly at the TZ point, it will always be at GND potential, not 5V etc.

Artaos
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### Re: SSF zero point oscilator

analogPedagog wrote:
Fri Jan 03, 2020 10:24 pm
Artaos wrote:
Fri Jan 03, 2020 9:31 pm
analogPedagog wrote:
Fri Jan 03, 2020 4:04 pm
Artaos wrote:
Fri Jan 03, 2020 3:18 pm
Question about the ZPO: can it do TZ FM without doing AM of the resulting waveform at the same time? For example: TZ-MOD set to Linear, a modulator into Linear FM input, ZP-INDEX knob at zero, no ZP modulator.
Based on what I understand so far in this discussion, it seems that a rectified version of the modulator would be applied to the core frequency, and that a non-rectified version would be applied to ZP (i.e. doing four quadrant multiplication or ring modulation between the modulator and the ZPO waveform). TZFM suggests a rectified frequency modulator, and a reversal of the waveform, not full amplitude modulation of the waveform. Can the ZPO do that?
There is no TZFM without a waveform reversal, but if you wanted just the FM component, you can set ZP all the way CW/CCW and only the slightest effect may occur, depending on the amplitude of the modulation. No extra ZP modulator is needed when an FM input is set to TZ-MOD.

Maybe it wasn't clear in some of the discussions, but the 4-quandrant multiplier is not linear, and operates very quickly at the zero crossing performing the waveform reversal. What you describe as full amplitude modulation is occurring much more quickly than a standard amplitude modulator.

So what is happening is not the same as using a normal TZVCA - I think this is an important point and may be what is central to your question?

I know I have been pretty open on how the ZPO works, but in case it isn't known, some already past/present designs have used a switch, or manage current flow into the VCO core, among others. I wouldn't be surprised if I am not the first to use a VCA to accomplish this. Point is, there are a number of techniques that have been used to manage this function in an analog implementation. This is simply one more with the extra feature of decoupling the two major TZFM components
Thank you for your answer. Yes, I think I am confused about how/why the ZP VCA affects the waveform. Let’s take an example of a sine carrier and a sine modulator, to help me understand, at a time t where carrier is +5V and modulator is 0V. (And there is no FM index.) With TZFM, since frequency modulator is 0, frequency should be 0Hz, i.e. the oscillator core should be stopped and the +5V output should be held constant. However if we introduce four-quadrant multiplication (as I understand ZP to be), then the output would be multiplied by 0, meaning output = 0V. So it seems to me that the waveforms are different?
So what you are asking is really just analogous to having nothing patched into any FM inputs and setting ZP dead center, in which case frequency = 0, output is completely null. So you are correct about the output becoming 0V, which is also constant.

This will the case with the exception of the SAW and RIPSAW, which are effected by the wave shaper circuitry and will produce a half amplitude pulse and multi-pulse, respectively.

There are ZERO TZVCOs out there that can actually be brought down to 0Hz via FM. Maybe you could get close if the OSC was set low enough but this is not what happens in an analog TZVCO as far as frequency modulation goes.
The effect and I stress effect of falling down to 0Hz is accomplished by reversing the current flow into the VCO core (traditionally).
So in other words, this effect of reaching 0Hz is an extremely fast transient state occurring at whatever point in the wave cycle that the reversal is initiated (traditionally a perfect implementation is supposed to flip near the waveform peak). The non-linear TZVCA in the ZPO behaves in a very similar manner, for that same brief amount of time, the frequency is absolutely zero. The difference on the ZPO is that the reversing nominally occurs around 0V and if you happened to be able to stop it exactly at the TZ point, it will always be at GND potential, not 5V etc.
IMG_2831.jpg
Thank you again. I am very curious about your implementation of the ZPO. I'm seriously considering the module (which is why I'm posting here). I thought I had an okay understanding of what TZFM (*typically*) means, but now I'm confused. I find it easier to use pictures rather than words. I attached a scope view of a completely different oscillator, in green. It is a falling ramp wave, and it is being modulated (linear FM, TZFM) by a triangle wave, in blue. We can clearly see the green falling ramp slowing down, as the blue triangle modulator approaches zero. When the modulator is at zero, the green falling ramp is flat for a brief period of time. As the blue modulator crosses below zero, the falling ramp wave is inverted into a rising ramp wave, and accelerates again. And vice versa on the second crossing from negative modulation to positive modulation. There is no fast transient when the reversal is initiated, and the reversal happens at any point in the waveform, not at the peak. This would be in line with my basic understanding of what people *usually* refer to when they mention through-zero frequency modulation.
Now, based on my (limited) understanding of the ZPO, given the fact that there is a bipolar VCA involved, I would imagine that a ramp through-zero frequency modulated by a triangle wave would result in a different waveform than this, where the green trace would cross zero when the modulator crosses zero (because of the bipolar VCA multiplication). To be clear, I am not arguing what is proper is what is not. I am simply curious about whether or not my understanding of those concepts is erroneous or if I "get it", and I am curious about the ZPO implementation and what it is / sounds like!
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analogPedagog
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### Re: SSF zero point oscilator

Yes, I do understand that you are curious about it.
I did post a couple of sound cloud audio demos, above that do a good job of showing what it sounds like.
Last edited by analogPedagog on Sat Jan 04, 2020 8:05 am, edited 1 time in total.

joey
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### Re: SSF zero point oscilator

Spent a bit of time with the ZPO, and I must say it definitely is not the typical thru zero oscillator.

I think that's a good thing in a way, because we've heard those sounds a billion times by now.

This is something new and cool and special. I dig it a lot.

brandonlogic
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### Re: SSF zero point oscilator

analogPedagog wrote:
Fri Jan 03, 2020 9:18 pm
Had a few minutes to spare so here's round 2 of the SINE mods SINE demos.

This is a very similar patch but now with the modulator first going through a passive attenuator. The envelope is again applied to Zero Point and is removed at roughly the 4:20 mark.

Random tunings here, perhaps got a little handy with the frequency but I think you will get the point. Various levels with the attenuator as well as offsetting ZP manually.

Thanks for the demo it sounds great!

Funky40
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### Re: SSF zero point oscilator

ok, hope my english is doing it: (edit: and sorry, its a LONG POST ! )

The demos show all the hi-frequenzy content percussions.
i´m myself a sucker for such tones, don´t get me wrong.
But i would call this area the: "VERY nice FM area"

To me, one important feature of a "real" TZ-FM VCO ( i don´t see me as a purist in any way btw. ) is that you can set it also to an initial Frequenzy of 0Hz respectivly very close to.
Aboves statement from analog pedagog that it requires FM (to get close to or even to zero Hz) is from a "patching standpoint" not true ( technically thinking it might be, since one might add an offset to the VCO core).

I have had several analogue and digital TZ-FM VCOs. the digital ones never did it btw.
To me, there is something special to have with some TZ-FM VCOs, i would call it: The "special sauce TZ-FM Tones".

This lies within the low frequenzy range. (its all about sine on sine then ! )
IIRC, Ideally one would patch the VCO to a VERY low frequenzy but not completly zero ( which would be its own thing, imo) and further would one work with different pitch sequenzes for carrier and modulator. The modulator having quite drastic pitch changes iirc, the carrier less so.
With some luck, .........and it was allways luck to me, respectivly some try&error to get there......., can you have fantastic Bass tones , with a VERY VERY round and musical tonal touch.

Pinging filters can have a similar effect, since the filter is "coming up" from nothing into audible ringing,.....just to give a picture to what i want to point,
but that effect can have with TZFM VCOs an audible quality that is way different than what filters would spit out.

The ZERO-VCO from Cynthia was spitting out such tones.
While i never "really" could dive into these tones with the Teezer. I never had an idea why.
I allways thought its max FM index might be smaller........? anyway
( i just grabed the Teezer yesterday again out of a box, will install it again later today.....and see)
And i never heard such tones in any TZFM VCO Demo so far i think. Even back then were just a few of the (internet active poeple) aware of that type of patching.

i´d really like to see such patch attempts with the ZPO.
VCO set to low frequenzies, going super low with the applyed pitch CV, modulator goes from VERY high to low or even also super low,
again: its a thing of luck to get matched pairs of pitch versus the "pitch movement" that is going on in the carrier VCO .

Now, what i don´t understand is: if it was different for our ears if the frequenzy turns to zero Volt, respectivly unaudible state versus the Amplitude turning to zero volt, respectivly inaudible state ??
But my guess is that it would or could make a difference within (very) low frequenzy content tones. While i´d see that it might be no different for our ears when the frequenzy runs above a certain level ??

these type of tones even feel like they´d sound the way the curves in the above scope shot are looking.,
i´m personally missing these tones since i sold the ZERO-VCO. Never had them again..........

but here with the ZPO, the interesting part is really how much our ears would hear it as the same (or not) ???
and how much the ongoing frequenzy (of the VCO) plays a role:
zero Volt by frequenzy versus zero volt by amplitude......??? .......Guess thats finally the math here, right ?
( seriously interested..........not beeing a purist......and not saying only the one thing is the right thing , since in modular land ALL modules would lead to own patchings vs. another anyway.... )
For sale / reduced prices ( swiss (we are NON-EU)/ in case it makes sense_ EU/WW)(CHF +- = \$):
lowered prices: Dotcom Q960: 650.- / Q119: 420 / ( i also have one or much likely two 19" Frames)
ATV A-Frame incl. Accu and Bag: 830.-, like new, quasi unused.

brandonlogic
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### Re: SSF zero point oscilator

Funky40 wrote:
Sat Jan 04, 2020 10:26 am

IIRC, Ideally one would patch the VCO to a VERY low frequenzy but not completly zero ( which would be its own thing, imo) and further would one work with different pitch sequenzes for carrier and modulator. The modulator having quite drastic pitch changes iirc, the carrier less so.
With some luck, .........and it was allways luck to me, respectivly some try&error to get there......., can you have fantastic Bass tones , with a VERY VERY round and musical tonal touch.
Interesting! Do you have or know of any audio examples of what this sounds like?

Artaos
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### Re: SSF zero point oscilator

analogPedagog wrote:
Sat Jan 04, 2020 7:11 am
Yes, I do understand that you are curious about it.
I did post a couple of sound cloud audio demos, above that do a good job of showing what it sounds like.
Thank you. Based on your answers, it seems to me that the ZPO is not capable of TZFM. For maximum clarity to other readers, "TZFM" in my posts refers to an oscillator whose frequency decreases as the frequency modulator approaches zero, then holds constant voltage as the frequency modulator is zero, and then smoothly starts oscillating in the reverse direction (reverse shape) as the frequency modulator crosses zero into negative modulation. It's a clear concept, and I share this definition of it with others. A concrete example is seen in the above oscilloscope shot.

Sound is what's important in the end. I personally enjoy the sound of that definition of TZFM. For those who don't, this whole conversation probably doesn't matter. For those who do, I hope this conversation helps. Since (as I now understand it) the ZPO is a regular oscillator core with rectifiers on the FM inputs, and a non-linear four-quadrant multiplier on the output, that is something I can patch with my current non-TZFM oscillators and the rest of my system. Whereas an analog TZFM oscillator (using the definition above) is something hard to design, and something that I am not able to patch from the modules I have, which is why I am interested in acquiring those oscillators. I expect the ZPO implementation of (non-TZ) FM followed by non-linear AM to sound more aggressive and glitchy (which seems supported by the sound demos). I am considering getting one because I like those tones as well. It is simply important to me to understand what my modules are and what they can do.

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### Re: SSF zero point oscilator

brandonlogic wrote:
Sat Jan 04, 2020 10:46 am
Funky40 wrote:
Sat Jan 04, 2020 10:26 am

IIRC, Ideally one would patch the VCO to a VERY low frequenzy but not completly zero ( which would be its own thing, imo) and further would one work with different pitch sequenzes for carrier and modulator. The modulator having quite drastic pitch changes iirc, the carrier less so.
With some luck, .........and it was allways luck to me, respectivly some try&error to get there......., can you have fantastic Bass tones , with a VERY VERY round and musical tonal touch.
Interesting! Do you have or know of any audio examples of what this sounds like?
Yes that would be great - and see if we can also get those sounds with the ZPO?

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### Re: SSF zero point oscilator

brandonlogic wrote:
Sat Jan 04, 2020 10:46 am
Interesting! Do you have or know of any audio examples of what this sounds like?
No, i never heard any recordet demos.
If i had some recordings was it on an older computer whichs harddrive died.
But i saw that aspect also mentioned 2-3 times by other people in the depth of some TZ-FM Discussions.
also allways related to Cynthias ZERO VCO ( which was for a long time the only TZFM VCO available, afaik )

i stumbled just recently over a recording from timoka in the "whats your favorite non-Drum module for percussions" thread
viewtopic.php?f=16&t=188624&start=50

thats much likely the first time i heard a recording giving me the same or at least similar feels.....like what you can have from (some, or just the ZERO?) TZ-FM VCOs ( sine on sine) when focussing on patching Basses.
For example focus at the passage from sec27 to sec52......after listening to the whole ofcourse
well, or just the first 25 seconds. Listen to it again and again........you hear the magic ?
you hear how the lower tones come in ? you can have even "rounder" sounding Tones with TZ-FM, yet still beening VERY Bassy.

Take this recording as an Idea to keep in the backhead, then you hear when you reach into that region
we speak mostly something subtle here. .......Buuut not only. TZ-FM can spit out some strange tones in that "tonal area".

Timokas Demo has a little another tonal quality to it when its about to analyse the gold within those Tones.
if you listen closer can you hear Ringings that are *much* in the vein of a real percussion mebrane. Its absolutely awesome !
The TZFM Bass tones i have in mind would i hang up on the term: "round & deep"........but very similar sounding at first.

try Folks, just patch with low frequenzy tones in the focus.....and look what you come up with with the ZPO.
would be interesting to see.

( as sayed: it was allways a hard work with plain luck involved respectivly going by feel and try and error to get there with the ZERO.
so take it as a grain of salt maybe )
But: i miss those tones since then........(had to sell my zero since it was a 5U unit)
For sale / reduced prices ( swiss (we are NON-EU)/ in case it makes sense_ EU/WW)(CHF +- = \$):
lowered prices: Dotcom Q960: 650.- / Q119: 420 / ( i also have one or much likely two 19" Frames)
ATV A-Frame incl. Accu and Bag: 830.-, like new, quasi unused.

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### Re: SSF zero point oscilator

Funky40 wrote:
Sat Jan 04, 2020 5:46 pm
brandonlogic wrote:
Sat Jan 04, 2020 10:46 am
Interesting! Do you have or know of any audio examples of what this sounds like?
No, i never heard any recordet demos.
If i had some recordings was it on an older computer whichs harddrive died.
But i saw that aspect also mentioned 2-3 times by other people in the depth of some TZ-FM Discussions.
also allways related to Cynthias ZERO VCO ( which was for a long time the only TZFM VCO available, afaik )

i stumbled just recently over a recording from timoka in the "whats your favorite non-Drum module for percussions" thread
viewtopic.php?f=16&t=188624&start=50

thats much likely the first time i heard a recording giving me the same or at least similar feels.....like what you can have from (some, or just the ZERO?) TZ-FM VCOs ( sine on sine) when focussing on patching Basses.
For example focus at the passage from sec27 to sec52......after listening to the whole ofcourse
well, or just the first 25 seconds. Listen to it again and again........you hear the magic ?
you hear how the lower tones come in ? you can have even "rounder" sounding Tones with TZ-FM, yet still beening VERY Bassy.

Take this recording as an Idea to keep in the backhead, then you hear when you reach into that region
we speak mostly something subtle here. .......Buuut not only. TZ-FM can spit out some strange tones in that "tonal area".

Timokas Demo has a little another tonal quality to it when its about to analyse the gold within those Tones.
if you listen closer can you hear Ringings that are *much* in the vein of a real percussion mebrane. Its absolutely awesome !
The TZFM Bass tones i have in mind would i hang up on the term: "round & deep"........but very similar sounding at first.

try Folks, just patch with low frequenzy tones in the focus.....and look what you come up with with the ZPO.
would be interesting to see.

( as sayed: it was allways a hard work with plain luck involved respectivly going by feel and try and error to get there with the ZERO.
so take it as a grain of salt maybe )
But: i miss those tones since then........(had to sell my zero since it was a 5U unit)
Yes, that recording sounds super nice! I think I am understanding that magic you are referring to.

I know that it is more or less approaching the gold but it does sound like a vcf or lpg is at some play in that piece. Off the bat it reminds me of some of the richer tz patches via the zpo followed by the Stereo Dipole to take some of the edge off.

In any case, I will play around with it and see what we can come up with. I do understand as you say it may take some trial and error.

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### Re: SSF zero point oscilator

Funky40 wrote:
Sat Jan 04, 2020 5:46 pm

i stumbled just recently over a recording from timoka in the "whats your favorite non-Drum module for percussions" thread
viewtopic.php?f=16&t=188624&start=50

thats much likely the first time i heard a recording giving me the same or at least similar feels.....like what you can have from (some, or just the ZERO?) TZ-FM VCOs ( sine on sine) when focussing on patching Basses.
For example focus at the passage from sec27 to sec52......after listening to the whole ofcourse
well, or just the first 25 seconds. Listen to it again and again........you hear the magic ?
you hear how the lower tones come in ? you can have even "rounder" sounding Tones with TZ-FM, yet still beening VERY Bassy.
Huh? What you are hearing on the track is Cwejman Res-4 being pinged. It's a quadruple bandpass filter, not a TZ VCO. The Res-4 does sound amazing though.
Last edited by oldenjon on Sat Jan 04, 2020 8:49 pm, edited 1 time in total.
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