The Prophet 12 amoung Prophets

[jdt9517]

I haven't read that, but if it's so, the FM capabilities are quite limited.

[DavidDever]

The traditional ways based upon Dr. Chowning’s theories did not produce even close to a saw.  In the recording I link to below, I put together a saw wave with my DX-7.  The sidebands went well above 10,000 hz using the basic theory.  On the P-12, however, I couldn’t get sidebands much above 4000 hz using sine waves.

Isn't the mod matrix limited to 4 khz? I'm fairly sure that I read it somewhere which would also explain why you won't get sidebands higher than that.

Also - wouldn't you need a feedback loop (and only one operator) on a traditional DX algorithm? That example sounds to me like a traditional non-feedback pair of operators.

[jdt9517]

I think you can do it that way too.  However, I did it the "traditional" way with a pair of DX operators as Dr. Chowning describes in his training book.   Also, I don't think the P-12 has the feedback capability.  So, it wouldn't have been apples to apples.

[Grimulkan]

I think you can do it that way too.  However, I did it the "traditional" way with a pair of DX operators as Dr. Chowning describes in his training book.   Also, I don't think the P-12 has the feedback capability.  So, it wouldn't have been apples to apples.

Couldn't you use the mod matrix for FM feedback? The individual osc outputs are sources there.

I wonder if there is a modulation bandwidth difference between default FM & mod matrix FM. The mod matrix is definitely audio rate, but I don't know how far it goes.

[BobTheDog]

Double up the mod slots to double the FM effect, does that help?

[jdt9517]

I'll give it a try, but to do linear FM, the frequency of the carrier and the modulator waves must stay at the same ratio such as 1:1 or 1:2.  Otherwise, the sound will change from note to note.   So, I can't use an LFO to create it.  It will have to be one oscillator modulating another.

[jdt9517]

Double up the mod slots to double the FM effect, does that help?

Ok.  I tried using the the mod section along with the FM mod directly in the oscillator section.  Bottom line was that the higher frequency sidebands do not appear.  So, there must be some limitation within the programming which prohibits those higher frequencies.

However, I did play around with the FM and got a pretty good digital pad sound using a 1:1 ratio on the first two oscillators, # 1 osc being the carrier and #2 being the modulator. I added #3 as a saw wave.  #2's frequency is being somewhat modulated by LFO which gives the FM part a chorusing effect.  The sound is here.   https://soundcloud.com/jdt9517/p-12-solo

I tried imitating that sound on the P-08 and as predicted, it sounds a lot more analog.  https://soundcloud.com/jdt9517/p-08-solo

I took the sound a little further and made a short background piece.  I'm using the above tracks for the pad, the Pro-2 is playing the solo and bass.  EastWest softsynth is being used for drums.  Yamaha S-90 for piano,  https://soundcloud.com/jdt9517/2017-10-06-p-12-exp

[jdt9517]

Back to do some more analysis here.  For this post, I am comparing the use of two oscillators in the P-12, P-08 and as an analog baseline - the KARP Odyssey.  In each case, I again used the saw tooth wave for comparison both tuned to the same note. The low pass filter was wide open on each synth.  So, all the harmonics were coming through.  The second filter on the P-12 was not engaged.

As I'm sure many of you are aware, putting two oscillators together, in tune, does not have an additive effect.  There is actually cancellation of harmonics.  It's when they are placed somewhat out of tune with each other that all the magic happens.

In this first recording, I started with a single oscillator and slowly turned up the volume on the second.  As the volume increases of the second oscillator, the harmonics cancellation can be heard.  In this first recording, the synths, in order are the P-12, P-08 and Odyssey.  The P-12's cancellation occurred mainly in the mid range.  Some mid-high and low frequencies start being accented as the volume of the second oscillator increases.  With the P-08, the harmonic cancellation is more consistent across the spectrum.  The overall effect is the volume reducing as the second oscillator is dialed in.  The Odyssey, I was not able to get perfect tuning (after all, it's a VCO  ).  When the volume of the second oscillator is increased, there is cancellation, but there is some phasing since the oscillators are not perfectly aligned.

   https://soundcloud.com/jdt9517/2017-01-13-p12-2-oscs-compared

Next, I detuned the oscillators slightly which is the base for many of the classic analog sounds.  I started with the Odyssey, using a slight detuning that I typically used in programming analog synths in the past.  That "classic" sound dialed right in.  I used approximately the same detunings on the P-12 and P-08 using no slop to compare.  I was amazed how close the P-12 got to the classic sound with the minor detuning.  The P-08 is the last sound on this second recording.  I was amazed how un-analog it sounded.  The classic phasing was not there.  While I did not record it, I had to use much more detuning to approach the classic sound. 

What this tells me is that I can use a more traditional approach with the P-12 to get the classic analog sounds.  The P-08 will require more detuning or slop to get there.  While I was not really aware of this, I looked back on some of the programs I have done on the P-08 and found that the detuning was more extreme than I probably would have used on say the P-05.

https://soundcloud.com/jdt9517/2017-01-13-p12-2-ocs-detuned

[Sacred Synthesis]

I'm perhaps not using these recordings as you've intended, but what strikes me is how much warmer and fuller the Prophet '08 sounds compared with the Prophet 12.  But I even preferred the sound of the P'08 over the Odyssey.

[jdt9517]

Your comment is welcome.  It's one thing for me to discuss my opinions.  It's quite another to hear the tracks and decide for yourself.  I'm doing the recording in part to evoke discussion.  It's definitely been a learning experience for me to try to put this together in a disciplined way.

Personally, I liked the sound of the P-12 over the P-08 in that test.  To me, it had a more pleasing phasing sound.  One thing is clear, these are not identical instruments.  Nor do I think one can completely imitate the other.

Here's the latest from tonight.  i went to the square wave on each instrument.  I put each at 50% on the pulse.  The first group is P-08, P-12 then Odyssey.  The differences of the raw waves is pretty substantial.  The Odyssey has the most overtones according to the oscilloscope.  However, it is the least accurate square wave.  The P-08 has more harmonics than the P-12, but the P-12 was the most precise square.   

The second part of the recording is where it starts getting fun.  I brought in the second oscillator and detuned it sharp 1.5 hz on each instrument.  I also used pulse width modulation on each instrument.  To be fair to the Odyssey, I used one LFO to modulate both oscillators for each.   i tried to adjust the speed of the LFO's so they were all going at similar speed.   Also, in each case I slowed down the attack a little and gave them all a little longer release so it sounded a little more like a real patch.  Still no adjustment on the LPF.  So, we are hearing the full breadth of the oscillators in each case.

Verdict?  i think the P-08 and P-12 are in a dead heat in this one.  I'll post the order a little later - but the Odyssey is first on the second round. 

https://soundcloud.com/jdt9517/2017-01-14-p-12-sq-wv-test

[Sacred Synthesis]

https://soundcloud.com/jdt9517/a-new-king

JDT, I really like this little piece.  It would be a nice introduction to a thematic piece, sort of a prelude followed by a fugue.  Is there more to it?

[jdt9517]

Thanks.  Not right now.  It's designed time wise to fit in music library requirements for TV/Film.  It could easily be expanded  - just where I don't know.

If you like this, you might like this recording.  https://www.youtube.com/watch?v=_fp33EBNrsg

In this recording, I took Beethoven's sketches of his Tenth Symphony.  It's in a pop format, but I think his two main themes found at the beginning and in the bridge of this composition are pretty accurate.

BTW, it was recorded at a time when my equipment was relatively crude.  Most of the instruments are played on my Yamaha S-90.

[Sacred Synthesis]

Very nice.

[psionic11]

JDT, I'm a new member, but I've followed this thread for about a month.  Thanks for researching and posting your results.  OSC phasing and harmonics are definitely a key component to that elusive analog quality.

I've had some P12 OSC harmonics and therefore volume phase cancelling that tend to give a kind of sameness to all patch creations.  Guess I need to use more slop and mod routings.  But I''m leaning more to filters and envelopes for getting that *desired response*.  What's your verdict on those versus OSCs?

[jdt9517]

I've had some P12 OSC harmonics and therefore volume phase cancelling that tend to give a kind of sameness to all patch creations.

Would you provide a short recording of what you are experiencing?  I'd like to hear what you feel the problem is before I comment.  There are a number of ways to avoid phase cancellation.  Just want to make sure (1) what you are dealing with is phase cancellation and (2) if not, what are you dealing with?   Thanks!

[jdt9517]

Another little addition to this section.  On another thread, a poster was trying to do sweeps with the high pass resonance filter.  He was turning the knob manually and was complaining about incremental stepping on the sweeps.  I have found that manually doing sweeps on the P-12 using the frequency or resonance knobs will not be completely smooth.  The knob will modify the filter incrementally and will create a minor stepping sound.

For a completely smooth sweep, a pedal set to mod the filter, an LFO, or an envelope needs to be used.

The post also led me to experiment with the HPF some more tonight.   Prior to the Pro 2 and P-12, my experience with a HPF was limited to the Odyssey (both original and the KARP).  The HPF on those instruments was not much more than a tone control. 

This HPF is a totally different beast.   Not only is there the filter itself, but there is a resonance function.  The HPF is self resonating which I did not expect.  My mistake was finding out the filter was self resonating with the volume turned up.     So, when experimenting with the HPF in the P-12 be careful to keep the volume to a low level.  When it resonates it RESONATES!

Attached is a recording I did tonight experimenting with the self resonance of the HPF.  The HP resonance is being controlled by envelope #3 and is set to repeat.  Slow attack and delay.  Sustain and release set to zero.  The amount of envelope is set so it will push the filter slowly in and out of self resonance.  There is reverb and delay added to the track.  Otherwise it is a single track of the P-12.  When you listen to it, make sure your speakers or headphones are set to a lower level. 

https://soundcloud.com/jdt9517/screech