The PolyMoog in your Virus

Over the years, there were a couple of requests for Vox Humana patches on this forum. Just recently, I stumbled over one of those threads and started to wonder whether it could be done. Since I don't have access to a PolyMoog 280A, I was stuck until I found this:

Zitat von Vstream

Download them here (choose sfz+wav). These wave files can be played on every wav player.

I have tried to program the Vox Humana on different synths. Some were very good but making an "exact" replica is nearly impossible.

Mostly they lack warmth and fatness and sound much to bright in the lower regions.

However the Virus Ti does (should do) an excellent job. The trick is to use a Saw and Pulse waveform. Use correct LFO's settings --> pitch and Pulse width modulation and a 3rd LFO for this classic sound.

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Last night, I downloaded the files (Thanks Joeri!) and used them as reference to try a couple of different approaches on the Virus TI.

Please find attached two patches, which IMO come reasonably close. I tried also to make them use as little resources as possible, on order to keep polyphony high in multi/sequencer mode.

• VoxHmn1 uses the HyperSaw oscillator
• VoxHmn2 uses the suggested approach of combining saw and pulse waves and modulating detune and pulse width with three LFOs
• VoxHmn3 is a refined version, using three LFOs to separately modulate the pitch of both OSC and the PW of OSC 1. Additional refinement include LFO speeds, OSC 1 pulse width, OSC 2 detune, filter characteristics, filter tracking, EQ, and velocity sensitive attack. Use the second filter and effects to taste.

These are sort of raw templates for the basic sound and need their Amp Envelopes, Velocity sensitivity and FX adjusted to taste.

Please let me know what you think. Maybe together, we can create the ultimate PM patches.

Edit: Removed outdated download. Please use patches available below.

I just realized that I uploaded the wrong set of patches. Those were the different trials. Fixed to contain the two sounds described in the first post.

Zitat von jan7geerts

email Matt, and he'll send you the Virus Numan sounds as well

Last night I contacted Matt, and he was kind enough to send me his patches, plus give some additional advice to get closer to the sound. Therefore I reviewed my patches, compared them with Matt's own and his notes. He mentioned that his VH patch only uses 2 LFOs and 2 saws, and that I should set one OSC to pulse, and use a third LFO for PWM, set at a lower rate than the two LFOs modulating the pitch of the two OSCs. Turned out that I was wrong about how the LFOs should affect the OSC. Matt's settings for the LFOs modulating pitch were very helpful go get me in the ballpark for the character. However, it didn't yet sound right, especially the PWM sounded weird.

Spend the better part of this afternoon doing some additional reading and listening and fine tuning. The most important part of this sound seems to be to capture the character of the LFOs, which produce and multidimensional movement and beating. After reading up on the technical aspects of the Polymoog 280a, I figured that there's actually three LFOs, but unlike in the Virus they affect all notes in the same way. Therefore the LFOs in the Virus must be set to mono. However, the one thing I'm still not sure is whether the Polymoog LFOs produce a triangle or sine wave. And I have a hard time figuring that out from the sources I have access to.

One further important aspect is that the PM280 does not have the typical Moog 4 pole ladder Filter, but instead just a very simple 2 pole filter for each note. This filters is incapable of being modulated or any resonance, and the settings are hardwired for each preset. Thus, I also changed the filter on the Virus to not produce any "colour" anymore, but just get rid of the upper harmonics.

About four hours later, I ended up with a patch which to my ears is pretty indistinguishable from the real thing. At least when I compare it to samples and YT videos of the Polymoog Vox Humana sound. Naturally there's a difference, but there's also a difference between any two analogue hardware synths, plus there's a couple of aspects which can be tweaked in the original sound: Modulation intensity, attack, detune, loudness balance over the key range and low pass filter for the lower register.

Please find the file including the patch "VoxHmn3 OZ" attached to the first post.

Some interesting links:

• A critical review of the Polymoog's technology
• Scans of the Polymoog User Manuals

In addition to the Kontakt patch by Stephen Howell using the samples by Joeri Peeters, I used this video as reference

Zitat von jan7geerts

very much interested in this, but with the new Mac Os update, the Virus soft isn't working anymore....

Oops. But there are a couple of threads dealing with those issues. It should work.

Anyway, I did another version of the Vox Humana sound, which IMO is even closer. I mainly changed the speed and amount of the LFOs. Will upload an update soon. I also started to work on the Polymoog 280a Strings I & II presets. Not really there yet, they still require more research and fine tuning.

OK, here they are.

Patches for the Virus TI recreating the first 3 presets of the Polymoog 280a keyboard:

• Vox Humana
• Strings I
• Strings II

These patches are based on the samples made by Joeri Peeters and various information about the inner working and control of the Polymoog 280a keyboard found on the internet. I used the MeldaProduction MOscilloscope and SugarAudio Oscarizor to analyse the samples and continuously compared them to the sound from of the Virus.

Since I don't have a real Polymoog 280 handy, I don't know how close they are to the real thing, but to my ears these patches are almost indistinguishable from the samples even when played side by side. Given that these samples are regarded to be some of the best ever made, I assume any sonic differences to be within the adjustment tolerances of any two original Polymoog keyboards.

Notes for usage:

• Attack is sensitive to key velocity, like on the original.
• The patches select the proper sections on the Virus for direct control of the sound: Control knobs are activated to control Filter 1, Reverb and Phaser.
• Filter 2 and Analog Boost and the Filter Bank are used to get the basic characteristic of the Polymoog. Filter 2 approximates the fixed Polycom filter and adjusts brightness per key.
• Filter 1 is to be used like the main filter on the Polymoog. The original VCF is a single filter for all notes. Thus, for most authentic results, Filter 1 should be set to Low Pass and there should be no key tracking and no envelope applied.
• Use the Detune control knob to adjust detune like on the original.
• Use the Mod Wheel or the soft control labelled Depth to increase the LFO amount for the pitch and pulse width LFOs similar to the original.
• Use the soft control labelled Speed to change the LFO amount for the pitch and pulse width LFOs similar to the original..
• Use the soft control labelled Tone to make the lower keys darker. This is an approximation of the low register filter available on the Polymoog.
• Phaser: Use the Type/Mix control knob to add phaser to taste.
• Reverb: Use the Send control knob to change the amount of reverb.
• For best approximation of high and low register characteristics, two instances of the same patch can be used with different settings for Tone or even lowerering the frequency of Filter 2 for the low register patch. Depending on the preset, you should even consider a slightly wider pulse width for the low register patch. I tried to compensate for that by applying key tracking to the pulse width, but the change of pulse width is definitely not linear across the keyboard. In the low register (below around F2) the pulse width seems to be wider by about 5%.

Any feedback is welcome. If you like these sounds and use them in your music, I'd love to hear about it.

Enjoy!

I just realized it would be more convenient to use Filter 2 to emulate the Polycom filter and have Filter 1 available for the main VCF, which would allow to use the 4 pole and Analog modes for more creative freedom.

However, I don't know how much of a sonic impact swapping the filters has. Mathematically, I'd expect the result to be the same (due to multiplication) but the filters may behave different.

I will have to investigate this.

As expected, the sequence of the Filters does not make any difference, as long as the filters do not introduce any non-linearities such as distortion -- which is not the case for these presets. Thus I swapped the application of Filters 1 & 2.

I also did slight adjustments to the Character, the LFO amounts and added a soft knob to control the speed of all three LFOs, approximating the modulation controls of the original.

Enjoy.

I'd like to add some information on how to approach recreation of Polymoog sounds for future reference:

• The Polymoog uses a TOS (Top Octave Synthesizer) system very much like found in organs. This means that there is actually a single oscillator circuit which creates the basic pitches for all twelve notes at a very high pitch, which are then divided by octave dividers. Therefore, no detuning is to be expected for single keys, and that an LFO modulation will be identical for all notes. There are actually two of these TOS oscillators available, one used to create a sawtooth and the other to create a pulse wave. The pulse width can be modulated, but again identical for all sounding notes. However, the two TOS can be detuned against each other.
• There are 3 LFOs available: One LFO for the sawtooth pitch, one LFO for the pulse pitch and one LFO for the pulse width modulation. Again, unlike in the Virus, where every voice has its own set of 3 LFOs, these are 3 LFOs which modulate all voices identically. I was not able to find any indication whether the LFOs in the Polymoog use a sine or triangle wave, but to my ears a triangle modulation sounded closer to the original.
• On the Polymoog models, there are several filter systems. Unlike other known Moog synthesizers, the Polymoog 280 A did not have the well known Moog ladder filter design. The first filter, provided by the Polycom IC, is a non resonating 2 pole low pass filter for each key, which can not be modulated in any way and is just used to remove brightness. Then there are custom filters for each of the "Modes" (sounds), which can be LP/BP/HP and 12 or 24 dB. On the Polymoog 203 Synthesizer, there is also a 4 pole low pass filter with resonance positioned before the main outputs. This main filter could be modulated with its own LFO, but it does not have a filter envelope. The PM203 also has the Resonator, a three-band multimode filter system with resonating 6dB/octave filters. See here for detailed reference.
• There are no effects on the original. Use chorus, phaser, reverb and delay to fit your music.
• Very important: The PM was designed to sound as clean as possible, so there is no distortion going on at any stage, not even in the filters.

So, to get a generic Polymoog layout, set up your Virus as follows:

• OSC 1: Classic Oscillator set to Pulse, 0 or -12 semitones
• OSC 2: Classic Oscillator set to Saw, 0 or +12 semitones, Detune as desired
• LFO 1: Mono mode (!), Triangle, modulate OSC 1
• LFO 2: Mono mode (!), Triangle, assign to modulate OSC 1 Pulse width
• LFO 3: Mono mode (!), Triangle, assign to OSC 2 pitch
• Filter 1: Use like the Mode or Main filter. Probably no key follow, use LP/BP/HP 12 or 24 db.
• Filter 2: Use like the Polycom filter. Key follow to reduce brightness on lower keys with a 12 db LP.
• Character: Analog Boost, Intensity 75%, Tune 127. I found this to give a similar frequency response to the frequency spectrum as found in good samples. However, I also used the Filterbank with a HP filter to remove some of the rumble. An alternative is to use Vintage 3 character which is produces less sub bass.
• Filterbank: Use to either emulate the main filter (4 pole, 24 dB, LP) or one of the Resonator bands (1 pole, LP/BP/HP).

I hope this helps everyone to get closer to the desired sound.

Happy Holidays

Zitat von GESchwalm

That is some really great research, Oli !! Thank you for sharing! Any advice on coaxing some of that special magical tone (other than choir sounds) of the PPG Wave 2.2 out of the TI2 ?

Please check out this new thread: The PPG Wave in your Virus TI.
And sorry, but I did the choir sounds...