Prophet History : Saw ramp up or down?

[LPF83]

When I first noticed that the saw wave orientation (ramp forward vs ramp reverse) was different between the Rev 1/2 and Rev3 filter options of my Prophet 10, I was a bit surprised, since I had not read about that anywhere prior (I since found a thread on GS that brought it up, but nobody else seemed to be talking about it).  Interesting that a filter choice would affect the oscillator orientation, no?

Then I remembered from reading The Prophet from Silicon Valley.... when Dave switched from SSM chips to Curtis (due to manufacturing / reliability issues), he sent the folks at Emu a letter announcing he would no longer be paying royalties for the SSM design since the Prophet 5 had been basically redesigned with the Rev3.  There was a bit of legal maneuvering over this, a few hard feelings it seems, and the guys at Emu apparently ceased their plans to take the Emulator (which hadn't been released yet) and sampler design ideas to Sequential for proper manufacturing/distribution due to the newly formed friction between the companies that resulted.

So, I was wondering if maybe the saw ramp was reversed across revisions in order to help solidify the proof of redesign.  I mean Dave is a clever fox, and in my mind such a move would have been fully fair play -- but in thinking about it, it makes perfect sense.  In fact it would have been a somewhat brilliant way of proving differentiation between one product or another, visually and scientifically (without making a huge difference in the sound output) to a potential audience of legal lookers on who know nothing about audio engineering or bits and bytes, but can visually recognize the difference between a ramp or a reversed ramp.

I should make it known I started the thread without any intention of a conclusive answer.  I just thought it might make for interesting discussion?

[CPN37]

When I first noticed that the saw wave orientation (ramp forward vs ramp reverse) was different between the Rev 1/2 and Rev3 filter options of my Prophet 10, I was a bit surprised, since I had not read about that anywhere prior (I since found a thread on GS that brought it up, but nobody else seemed to be talking about it).  Interesting that a filter choice would affect the oscillator orientation, no?

Then I remembered from reading The Prophet from Silicon Valley.... when Dave switched from SSM chips to Curtis (due to manufacturing / reliability issues), he sent the folks at Emu a letter announcing he would no longer be paying royalties for the SSM design since the Prophet 5 had been basically redesigned with the Rev3.  There was a bit of legal maneuvering over this, a few hard feelings it seems, and the guys at Emu apparently ceased their plans to take the Emulator (which hadn't been released yet) and sampler design ideas to Sequential for proper manufacturing/distribution due to the newly formed friction between the companies that resulted.

So, I was wondering if maybe the saw ramp was reversed across revisions in order to help solidify the proof of redesign.  I mean Dave is a clever fox, and in my mind such a move would have been fully fair play -- but in thinking about it, it makes perfect sense.  In fact it would have been a somewhat brilliant way of proving differentiation between one product or another, visually and scientifically (without making a huge difference in the sound output) to a potential audience of legal lookers on who know nothing about audio engineering or bits and bytes, but can visually recognize the difference between a ramp or a reversed ramp.

I should make it known I started the thread without any intention of a conclusive answer.  I just thought it might make for interesting discussion?

Am I being stupid, I can’t recreate what I think you are talking about on my Prophet~5 Rev 4. Are you saying that, eg. if you set Osc B to Lo Freq and set it to sawtooth waveform modulating Osc A, and switch filter from Rev 1/2 to Rev 3, that the Osc B sawtooth orientation will change?

[LPF83]

When I first noticed that the saw wave orientation (ramp forward vs ramp reverse) was different between the Rev 1/2 and Rev3 filter options of my Prophet 10, I was a bit surprised, since I had not read about that anywhere prior (I since found a thread on GS that brought it up, but nobody else seemed to be talking about it).  Interesting that a filter choice would affect the oscillator orientation, no?

Then I remembered from reading The Prophet from Silicon Valley.... when Dave switched from SSM chips to Curtis (due to manufacturing / reliability issues), he sent the folks at Emu a letter announcing he would no longer be paying royalties for the SSM design since the Prophet 5 had been basically redesigned with the Rev3.  There was a bit of legal maneuvering over this, a few hard feelings it seems, and the guys at Emu apparently ceased their plans to take the Emulator (which hadn't been released yet) and sampler design ideas to Sequential for proper manufacturing/distribution due to the newly formed friction between the companies that resulted.

So, I was wondering if maybe the saw ramp was reversed across revisions in order to help solidify the proof of redesign.  I mean Dave is a clever fox, and in my mind such a move would have been fully fair play -- but in thinking about it, it makes perfect sense.  In fact it would have been a somewhat brilliant way of proving differentiation between one product or another, visually and scientifically (without making a huge difference in the sound output) to a potential audience of legal lookers on who know nothing about audio engineering or bits and bytes, but can visually recognize the difference between a ramp or a reversed ramp.

I should make it known I started the thread without any intention of a conclusive answer.  I just thought it might make for interesting discussion?

Am I being stupid, I can’t recreate what I think you are talking about on my Prophet~5 Rev 4. Are you saying that, eg. if you set Osc B to Lo Freq and set it to sawtooth waveform modulating Osc A, and switch filter from Rev 1/2 to Rev 3, that the Osc B sawtooth orientation will change?

The simplest test is to use Osc A, look at the wave with an oscilliscope plugin and switch between filters.   I just use Supervision because it comes with Cubase and does a lot more than oscilliscope.

It's going to be weird if I find out mine's an anomaly   I read somewhere else this is the case with vintage units between the first two revs and the third as well.

[Manbird]

When I first noticed that the saw wave orientation (ramp forward vs ramp reverse) was different between the Rev 1/2 and Rev3 filter options of my Prophet 10, I was a bit surprised, since I had not read about that anywhere prior (I since found a thread on GS that brought it up, but nobody else seemed to be talking about it).  Interesting that a filter choice would affect the oscillator orientation, no?

Then I remembered from reading The Prophet from Silicon Valley.... when Dave switched from SSM chips to Curtis (due to manufacturing / reliability issues), he sent the folks at Emu a letter announcing he would no longer be paying royalties for the SSM design since the Prophet 5 had been basically redesigned with the Rev3.  There was a bit of legal maneuvering over this, a few hard feelings it seems, and the guys at Emu apparently ceased their plans to take the Emulator (which hadn't been released yet) and sampler design ideas to Sequential for proper manufacturing/distribution due to the newly formed friction between the companies that resulted.

So, I was wondering if maybe the saw ramp was reversed across revisions in order to help solidify the proof of redesign.  I mean Dave is a clever fox, and in my mind such a move would have been fully fair play -- but in thinking about it, it makes perfect sense.  In fact it would have been a somewhat brilliant way of proving differentiation between one product or another, visually and scientifically (without making a huge difference in the sound output) to a potential audience of legal lookers on who know nothing about audio engineering or bits and bytes, but can visually recognize the difference between a ramp or a reversed ramp.

I should make it known I started the thread without any intention of a conclusive answer.  I just thought it might make for interesting discussion?

Am I being stupid, I can’t recreate what I think you are talking about on my Prophet~5 Rev 4. Are you saying that, eg. if you set Osc B to Lo Freq and set it to sawtooth waveform modulating Osc A, and switch filter from Rev 1/2 to Rev 3, that the Osc B sawtooth orientation will change?

The simplest test is to use Osc A, look at the wave with an oscilliscope plugin and switch between filters.   I just use Supervision because it comes with Cubase and does a lot more than oscilliscope.

It's going to be weird if I find out mine's an anomaly   I read somewhere else this is the case with vintage units between the first two revs and the third as well.

Mine does the same. Curious!

[CPN37]

Could it be an “Easter egg” in the Prophet 10 only and not the Prophet 5? Since the double manual Prophet 10 offered the reverse Sawtooth?

I’ll check my Prophet 5 Osc A nonetheless…although surely the Osc B being set to Lo Freq proves it ain’t happening on mine…

[CPN37]

hmm I downloaded an oscilloscope and sure enough my Prophet 5 exhibits the same behaviour: the sawtooth waveforms have a positive ramp in Filter 1/2, & a negative ramp in Filter rev 3.

I'm probably just ignorant to how this works but how come when you set Osc B to Lo Freq and use a sawtooth waveform to modulate Osc A, that both Filter positions sounds like the Osc B LFO waveform is a positive ramp?

[LPF83]

Could it be an “Easter egg” in the Prophet 10 only and not the Prophet 5? Since the double manual Prophet 10 offered the reverse Sawtooth?

I’ll check my Prophet 5 Osc A nonetheless…although surely the Osc B being set to Lo Freq proves it ain’t happening on mine…

It would be very easy for Dave to invert the wave orientation when the oscillator is in low freq mode on the second filter in order to keep patches relatively compatible and sounding similar between revisions... the orientation is  inconsequential at audio range, but if the LFO shape was reversed it would wipe out any patches from the Rev 1 or 2 that used polymod with OSC B saw when he released the Rev3, so I'm pretty sure that's what is going on.

[LPF83]

When I first noticed that the saw wave orientation (ramp forward vs ramp reverse) was different between the Rev 1/2 and Rev3 filter options of my Prophet 10, I was a bit surprised, since I had not read about that anywhere prior (I since found a thread on GS that brought it up, but nobody else seemed to be talking about it).  Interesting that a filter choice would affect the oscillator orientation, no?

Then I remembered from reading The Prophet from Silicon Valley.... when Dave switched from SSM chips to Curtis (due to manufacturing / reliability issues), he sent the folks at Emu a letter announcing he would no longer be paying royalties for the SSM design since the Prophet 5 had been basically redesigned with the Rev3.  There was a bit of legal maneuvering over this, a few hard feelings it seems, and the guys at Emu apparently ceased their plans to take the Emulator (which hadn't been released yet) and sampler design ideas to Sequential for proper manufacturing/distribution due to the newly formed friction between the companies that resulted.

So, I was wondering if maybe the saw ramp was reversed across revisions in order to help solidify the proof of redesign.  I mean Dave is a clever fox, and in my mind such a move would have been fully fair play -- but in thinking about it, it makes perfect sense.  In fact it would have been a somewhat brilliant way of proving differentiation between one product or another, visually and scientifically (without making a huge difference in the sound output) to a potential audience of legal lookers on who know nothing about audio engineering or bits and bytes, but can visually recognize the difference between a ramp or a reversed ramp.

I should make it known I started the thread without any intention of a conclusive answer.  I just thought it might make for interesting discussion?

Am I being stupid, I can’t recreate what I think you are talking about on my Prophet~5 Rev 4. Are you saying that, eg. if you set Osc B to Lo Freq and set it to sawtooth waveform modulating Osc A, and switch filter from Rev 1/2 to Rev 3, that the Osc B sawtooth orientation will change?

The simplest test is to use Osc A, look at the wave with an oscilliscope plugin and switch between filters.   I just use Supervision because it comes with Cubase and does a lot more than oscilliscope.

It's going to be weird if I find out mine's an anomaly   I read somewhere else this is the case with vintage units between the first two revs and the third as well.

Mine does the same. Curious!

Isn't it?  ...   so apparently what happened was Emu was getting a royalty on the Rev 1/2 due to the SSM chip design.  When Dave switched to CEM, he sent them notice that he wasn't going to pay royalties any more due to the new Rev 3 design changes.  They were a very small company and those royalties were funding a decent portion of their development, so they got lawyers involved and ultimately Dave settled out of court for $70k.   Water under the bridge, but obviously the saw wave orientation thing was brought into the Rev4 design, and it got me thinking it might have been part of a differentiation strategy to show the Rev 3 was a different product (without changing the formula that worked too much).