Polyphonic mode behavior

[Treelimbjim]

I have observed in polyphonic mode AND patching the VCA Output directly to drive something (reverb, ring mod, oscillator mod) its signal only appears on one voice.

Since the voices rotate round-robin its easy to hear it with two-voice polyphony:
Test patch with poly mode on, set to two voices, patch VCA Output to the reverb input labeled MIXER OUT. Pan hard left, turn up the Right reverb.  The reverb will be present on alternate keystrokes.

What I found puzzling is panning hard left and patching VCA Output to R. IN does not exhibit the single voice behavior.

An implementation issue in polyphony, but not exclusively at the VCA Output.

MacOS 10.13.1
ARP 2600 V3.2.0.1183

[LBH]

This behavior is true if you connect the VCA output into the reverb, instead of keaping the default hardwired VCA connection from the mixer.
But beside this i can't confirm your reporting.

About your panning example, have you remembered to turn down the VCA slider in the mixer? The reverb come from that. The Left and Right inputs don't go thru the reverb.

Can you post screenshots of other examples than with the reverb?

[Treelimbjim]

Thanks, I suspected as much a request. Here goes. This is my first thread on this forum.

BTW, I went through and attempted to re-created the 100 patches from 2600 Patch Book. Some of the patches lent themselves to polyphony and had a little reverb so I stumbled across this anomaly. I'm curious that someone else hadn't come across this and posted about it earlier.

Let me throw out a)OldSchool, a little bone from my CV b)NewSchool, A Lil Cred : I have been inside and worked on, much less played with most of these V Collection devices in the real world. I respect that emulating a hardware device in software is difficult enough. Then it comes to extending from there, it becomes another ball of yarn. Hats off to all ( including you, the fellow readers, players and engineers).

I will do my best to craft a presentation so that it leads you down the same path as I did. MacOS users, watch the left footer text.

<ArrogantUserModeON>
Familiarize yourself with the interface. References to Section (nn.mm...) are from Manual 3.0.0.
There should be unique outlets and controlled labeled
VCA Out (4.1.5)
Mixer Out (4.1.13),
Play mode selector (4.2 Keyboard interface) POLY mode switch
Polyphony menu (Section 3.2.10.4 Maximum Polyphony)
Panoramic Mixer (Undocumented!)

I am clear that patching overrides default behavior. The complexity of a software/device as this, one has to establish certain boundaries.

<ArrogantUserModeOFF>

Select 1 Osc Square from Factory List. Make the following adjustments:
Play Mode: Polyphonic
Polyphony Menu: 2 ( or at least >1 )
Patch VCA Out to Mixer Out
Panoramic Mixer: Left:1.00 Right:0.00
Amount Right Reverb: 0.8

Press and release a key (Section 3.1 or your own rig). Subsequently press and release the same key. Notice how one of the actions presents a full-left tone reminiscent of Factory patch "1 Osc Square", while the other includes a full-right reverb. Or rather, pointing out the garde-robe des rois -- a lack of reverb.

Those of you who choose to mask the anomaly/bug/interpretation by using a large number for polyphony ( >1) will be treated to the reverb output, you just have to cycle through to get the 1:n voice that contains reverb.

[LBH]

I have allready confirmed the issue you show with the screenshot. I asked for the other examples.

And yes it's a problem in Unison and Polyphonic sounds where you wan't reverb on the VCA but also have the mixers VCF output without reverb. This i also think Arturia should look at, even if the original was a monophonic synth.
If we talk original, then you should use mono, and then you don't have the voice issue. But i think it should work in Unison and polyphonic mode too.

And i can confirm that using the L or R in don't have this voice issue either.
I can add, that it's also strange, that if you take keep the pre wired VCA in the mixer and take the output above that VCA mixer slider and put it into the reverb, then you have the voice issue but the pre wired connection don't, as i wrote in my first post.

What i did'nt confirm was about your issues with OSC modulation and Ring modulation.
I don't see this voice issue in all situations. It's not there when modulating OSC's. That's why i ask for a screenshot, because it can be about how things is patched. It's more correct you post screenshots of your stuff.
What i can confirm further now is, that if you connect your examples directly into the reverb input in the ways that's explained, then you have the voice issue in Unison and Poly mode. And that i think should be fixed like other things should.
Also even if the original was mono. Your issues is'nt in mono mode.



About manuals and original patchbook sounds:

If you search the different forums, then you will see, that many think Arturias manuals in many cases could and should be better.

Also if you search the different ARP 2600 forums for all V-Collections, then you will see, that there are differences between the original hardware synth and Arturias version.

You can't create all the sounds from the original patchbook, because the Electronic Switch unfortunately is'nt bidirectional in Arturias version (this is requested), and the Ring modulator also don't match the original. If you see at the Ring modulator then even a switch is missing on Arturias version but it's labels are on the GUI (Audio - DC). Perhaps there are more.
Again remember the original was mono. Your issues is'nt in mono mode.

Unfortunately you can't exspect the patchbook sounds to be excactly the same when using the same parameter settings. But if you tweak the parameters, then you can come very close to the original. Sometimes you might need to do another patching.

[jeffbart]

Yes, did the same for me, including any audio output (e.g. VCF out)  going into the mixer out input. Only the first of 'n' notes will get played. Similarly for the VCF out into VCA input  (under 'Mixer'). Odd behaviour when the slider is e.g. halfway. Only one note appears to be passed through directly. Unfortunately I don't know this section of the 2600 well enough to know if it's meant to do this, or not !

[Treelimbjim]

Here's "1 Osc Triangle" with the VCF driving part of the Ring Mod. Again sending dry left and reverb right.

Where this may show up is in a useful poly or uni patch with a short envelope that would make the reverb pop. It manifested for me replicating 33. Glitter Guitar.