Responsiveness of Pro-2 Knobs

[Paul Dither]

I can adjust the knobs on mine with increments of 1.

All the knobs? I'm just asking, since this only works with the detented enconders in my case.

[BobTheDog]

Well the ones I tried, cutoff and res for the filters.

I get the initial jump (2 or 5) and then they increment by 1.

[Paul Dither]

Well the ones I tried, cutoff and res for the filters.

I get the initial jump (2 or 5) and then they increment by 1.

Gotcha. Yes that happens on mine as well. The jumps appear not only after using the pot for the first time though, but at any time at the extremes. On mine it's impossible to dial in "1" if I start from zero, it will always jump directly to "2" at least. Same for the opposite/maximum value. I can dial in "1" though from a higher value. If I want precise values, I always only use the detented encoders above the display. Conceptionally, the pots always seemed to me for dialing in approximate values.

[BobTheDog]

I must admit I tend to use the encoders as they are always in the "correct" place!

[binman_uk]

Case details so far:

Hi Adam-

Thanks for contacting DSI/Sequential. I'm happy to answer your questions and offer you assistance with your Pro 2. What's the serial number for your synth, and when/where did you purchase it?

First, it's good to note that any time you are using your Pro 2 in a MIDI feedback loop with a DAW or other hardware MIDI devices, this can cause small amounts of latency which, even if it's only a few milliseconds, can possible affect performance. The degree to which this may or may not happen depends on many factors, including the number of devices in a MIDI chain, computer processor power and software resource intensity. Regarding the video example you linked to specifically, are you in a MIDI loop here, as well (with Local Off, I presume)? Does your Pro 2 seem to behave any differently when edited standalone, with no USB/MIDI cables attached?

There are a few other factors that I'll mention that can affect control performance in general, in applications in which an analog potentiometer is digitally scanned and read by a microprocessor, as in most synthesizer applications (the Prophet 5 in 1978 was the first!). The first is hysteresis, which is necessary to smooth out performance. This creates a small amount of "wiggle room" on either end when you turn the pots. The second is the acceleration algorithm that we employ, which is used to increment/decrement greater values when the pots are spun more quickly. Although these factors may or may not be at play in your specific MIDI feedback look scenario, I thought I'd mention them anyway.

Fortunately, thanks to the soft knob/soft button navigation system in conjunction with the OLED display, you can always use a detented rotary encoder to make single value adjustments quickly, if you're having difficult dialing in an exact value with a potentiometer in your particular setup.

I hope this helps. If you have any questions, please feel free to ask.

Best,

Andy
Dave Smith Instruments

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April 11, 2016, 18:37
Adam Cummings
Hi Andy,

Thanks for the reply.
This occurs when no sound is playing and no midi/usb cables are attached. I actually created a forum post for it and it seems like quite a few people are having the same issue:

http://forum.davesmithinstruments.com/index.php/topic,442.0.html

I tried several different OS versions (1.1.15 and 1.2.0.2). The main issue for me here is that if I want to simultanously tweak a few parameters such as cutoff and decay for lets say a bassline, I can't do it without big jumps in the sound. In such cases I can't use the dented knobs either as most knobs are on different parameter pages. If using knobs that switch between parameter pages, the jumps are around 5-6 increments as well, which is pretty high in my opinion.

Is it possible to maybe increase the sensitivity? Or maybe provide a setting in the globals for people to adjust it?

Many thanks,
Adam

April 12, 2016, 01:37
Adam Cummings
I'll be in touch soon with the serial number - I'll have to check when I get home.
I bought it on 26th Nov 2015 from DV247.com here in the UK.

Thanks,
Adam

April 12, 2016, 01:39
Andy Lambert
Dave Smith Instruments
Hi Adam-

Thanks for your response. For clarification, the behavior depicted in the video you linked to is with your Pro 2 in a MIDI feedback loop with Local Off, correct? On the Pro 2 on my desk here, I'm not seeing jumps of 5 or 6 values on the display with small knob movements when the synth is operating standalone (not in a MIDI Feedback loop).

Also, I should note that with all of our instruments, audio is always prioritized over display update behavior, so that above all else, when you manipulate a control, you hear the effect in real time. While displays have become essential editing tools for many of us, myself included, your ears are always the ultimate test!

Thanks for linking to the thread you started on our official forum. We do read what gets posted there, though often other responsibilities make it difficult to do so right away. With technical support matters it's usually most effective for us to address users on an individual basis, as there are almost always individual factors at play when it comes to users experiencing a particular issue. Looking through the forum thread, it seems that what's being reported is explained either by potentiometer hysteresis or the display update priorities. If any user feels that this explanation doesn't account for what they are experiencing, I would encourage them to contact us directly here at technical support.

Regarding the example you give of editing multiple parameters that are on different pages simultaneously, you make a valid point in terms of not being able to use the soft encoders to dial in very small incremental changes in this context. However, from my personal experience using the Pro 2 in a live situation, as well as the more targeted experimentation I've done with the synth today preparing my response, I haven't encountered a scenario in which I get audible jumps when I'm tweaking controls. If you are encountering audible jumps when you're tweaking the front panel pots live, please let me know, along with steps for reproduction! We would definitely want to know if something like that were occurring.

I hope this helps. If you have any questions, please feel free to ask.

Best,

Andy
Dave Smith Instruments

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April 12, 2016, 15:57
Adam Cummings
Hi Andy,

Thanks again for your detailed reply.
In the example I showed there's no cables plugged in other than the power cable, so definitely no midi loop.
It's set to local on but I'm not playing any notes.

It's not exactly an issue with display updates as I'm not too bothered about what the screen actually shows - I used that as an example to show that the jumps are happening. The "wiggle room" either side of the knobs produces no change in sound whatsoever and then the display finally jumps 4-5 increments, the audio jumps along with it (only by a bit as the 4-5 increments would suggest.. but it's definitely audible and makes live tweaking of knobs a quite difficult).
That's the main issue you see.. either side of the knobs there's like a "dead zone" where nothing happens to the audio.

I'll have a play tonight and figure out an exact process to recreate this for you. I'll start with a basic patch with no modifiers and I'll also upload a video.

Thanks,
Adam"

[Cires78]

Hi guys,
My tuppence worth. I think I have the same issue with some of my knobs. One thing I've noticed is that if I'm trying to "zero" a parameter that's say, set at +3, it can be easier if I move the value up and then try to move back to zero rather than trying to "nudge" it down from the initial +3. When I do that, it usually overshoots to a minus value and then the same when I try to correct.
Hope that makes sense. 

[Fuseball]

I think this knob behaviour has been present on all DSI synths since the Prophet 12. The values skipped depend on the range of values for a specific knob. If I recall, a 0-127 range knob has to move by +-3 to get focus and be accurately tracked. On a knob with a wider range - filter cutoff or, even more noticeably, filter envelope amount (which goes from -127 to +127) I think it had to move by +-6 to get focus.

I've always assumed it is a filtering of the physical controls to eliminate any jitter. The Prophet 08 does this too but the tolerances are much finer so it only skips +-1 and the timeout before it filters again is longer. It's not something I ever notice on the '08 but it irritated me on the 12 and Pro 2.

If you hook up a Prophet-6 to a midi monitor or the Soundtower editor it does exactly the same thing too. It's less obvious without a display but very subtle oscillator detuning is trickier than it should be as a result.

[Chry]

Hi Folks,

are there any news regarding this topic or a solution ? I have this Problem too and its very annoying especially at Filter 1. I have seen it at some other knobs too, but not all. IS there any Solution like changing the Potentiometers ?

[BobTheDog]

It is a software thing, maybe they will improve it with the next update?