No analogue controls for analogue filter or oscillators

[robertsthebruce]

I love the sound of the P6, but I have a problem that is showing up more and more frequently as I use it more often. The problem is this: there is literally no way to control either the filter cut off or the pitch manually with actual voltage control. Even the filter jack in the back is a quantized control, which means there is no way to manually sweep the filter without hearing very audible stepping. The same problem exists with the pitch bend wheel/ midi funcion; there is audible stepping in the pitch bend wheel and an octave limit in the midi pitch bend function. What is the point of having a great sounding analogue filter and great sounding analogue oscillators if the only way to control either of them is through low resolution digitally quantized controlls? Again, I love the sound of the oscillators and filter, but this issue is...kind of a big deal. What does everyone else who owns one think? Are you feeling limited by these factors, or am I making a mountain out of a mole hill?

[Robot Heart]

The oscillators step in semitones for easy tuning. The filter is also harmonically tuned across a wide range, so it behaves the same way. To sweep without stepping, you can assign the LFO to the filter.

[robertsthebruce]

Right...I am aware that I can use the on board LFO. The issue I am pointing out is that the synth is also equipped with a filter CV input, the normal musical uses of which would be to control the filter with an expression pedal or modular piece of gear. However, unless you want to use an LFO to play a fast chromatic scale on the resonant filter, that CV input is rendered somewhat musically useless because it is quantized.

Similarly, I realize that the pitch of the oscillators is quantized to allow for easy tuning to one infamously out of tune western scale, but the function I am talking about is the pitch bend wheel, which by it's very definition needs to be able to break the limits of that quantization in order to function.

As both of these issues are clearly being governed and limited by the OS, rather than by hard wired circuitry, it would be nice if they were addressed, in order to render the filter CV input musically useful.

Again, the filter and the oscillators both sound great, but the ability to control them is limited by "features" that it's hard to imagine anyone making musical use of.

[DavidDever]

OK, this does seem strange; I thought that the point of the CV input, as well as the bender, etc., was to provide finer resolution, compared to the front-panel filter cutoff control, etc.

Why is it the case that I can do this on my Prophet-600 Gligli, but could not on a modern polysynth such as the Prophet-6? Is this a hardware constraint?

Also–given that the Prophet-6 and OB-6 share the same underlying control architecture, is this the case with the OB-6 as well?

[blewis]

I guess this is where I say it would be nice to sweep the filter with the Mod wheel and request (yet again) a 0Hz DC LFO setting to do so?

This request seems like a great way to address this reoccurring quantized  pitch/filter freq complaint and add a sensible,  coherent, and simple feature.

[LoboLives]

It would be nice for the new OS to disable the quantization for the tuning.

[Sacred Synthesis]

So the only way to create a smooth low pass filter sweep on the Prophet-6 is to use either an envelope or an LFO?  Is the high pass filter quantized also?  Surely it isn't.

[dslsynth]

So the only way to create a smooth low pass filter sweep on the Prophet-6 is to use either an envelope or an LFO?  Is the high pass filter quantized also?  Surely it isn't.

Are the OS filter the controls so that manual sweeps higher than a certain rate of change would sound smooth?

[Robot Heart]

You *can* get smooth filter sweeps on the Prophet-6 using the cutoff knob, just like any of our instruments. If you are trying to go really slowly, then it steps in semitones for easy tuning. This is how all of our instruments operate.

[robertsthebruce]

Robot Heart. I feel a bit unheard here. I'm not sure how else to say this; I, and I think everyone else in this conversation understands that this is how your instruments operate. That IS the issue. We would like them to operate differently; namely, to have some way to control the filter in a non-quantized way, because I, and many other people CAN actually hear stepping in the filter- not just at ridiculously slow tempos, but at any tempo where a chromatic scale would normally sound like a scale rather than a glissando, since that is literally what the quantized resonant filter on the P6 is doing.

It seems, from the way you advertised the synth, that you would be able to do this with a CV input, but I, and many other people were disappointed to find that we cannot. Why not keep the knob on the front quantized, since you seem so attached to that "feature," but make the advertised CV input on the back an actual CV control, or at the very least, a much higher resolution...this doesn't seem like a ridiculous request to me, and I don't understand why your response is to basically deny that it's really an issue.

I hear that it isn't an issue to you, but it IS actually an issue to me and many of your other customers. Is DSI a company that cares about that?

[Robot Heart]

I'm sorry you feel unheard. I hear you, I'm simply telling you how the instrument operates. I'm not trying to claim anything is or is not an issue for anyone. But because I know how our development works I am able to make reasonably accurate assumptions on how a feature request might play out, and I am communicating realistic expectations to you. It doesn't mean you have to like what I say though.

We do care about our customers, of course. We write down every request that is suggested, and many customer requests end up in the instruments.

I can tell you with the utmost certainty, because of my job function I am the single largest advocate for our customer base when features are discussed. While I am on the customer's side in most cases, I do not have the final authority to determine what will become a feature and what will not. Also, we simply cannot accommodate every request. This can be difficult and frustrating for anyone because naturally everyone's personal request is "the most important one", and it is, for their personal workflow. 

I *will* add it to the feature request list, and I *will* bring it up the next time the Prophet-6 OS is discussed. I will warn you though, given all our instruments operate in the same manner for this particular request it is very unlikely the behavior will change. The Prophet-6 OS is relatively mature at this point and we have our hands full with other projects, so it will probably be a number of months at the earliest before it is revisited. Hopefully we both have a better understanding of each other's respective positions at this time.

[Sacred Synthesis]

I make changes to the filter cut off frequency constantly while playing.  For quite a few compositions/improvisations, it's fundamental to the music, especially towards the end.  I've tried using foot pedals for this and, regardless of the pedal's quality (I've used the Moog as well as the old DSI), there's no comparison between using the foot and using the hand.  Trying to make a slow perfectly smooth sweep with your foot - whether while sitting or standing - is virtually impossible.  It's especially difficult if the filter change is slight or very slow.  And if you happen to be playing bass pedals, then forget it.  So, even if it worked smoothly, a filter sweep on the Prophet-6 made with a pedal is still of minimal use. 

I realize the Prophet-6 is the way it is, and that may never change.  So be it.  I'm not here to complain about it.  I'm simply saying that - for future reference - an instrument that cannot create a smooth filter sweep with a hand manipulated parameter - be it a knob, or much more preferably, a modulation wheel - is an instrument that cannot create a smooth filter sweep.  Period.  Pedals are difficult enough to use even for making volume changes, but all the more for something so delicate as filter changes, even when you can narrow their range.  Pedals should not be required for functions that are so essential to synthesis.

[dslsynth]

Maybe take a closer look at the algorithm filtering the front panel knob events for the filter cutoff knob(s)? Its a performance feature so it will not change how existing programs work but only how the filter cutoff knob behaves during changes. Maybe I should say: how the voice code reacts to the changes.

[LoboLives]

I've never had a problem with the filter being quantized at all. My ears can't detect it at all when I sweep....I mean you would have to be sweeping at an insanely slow rate for it to be detrimental I would assume.

[Robot Heart]

Sacred Synthesis-

The operation of the cutoff knob on the Prophet-6 is exactly like the Prophet 08; make no mistake about it.

[Sacred Synthesis]

Robot Heart -

Then what is the issue here?  The Prophet '08 filter sweep - however you do it - is as smooth as butter.  I use it constantly, always by the modulation wheel, and often very slowly and slightly.  I'm just trying to get a sense of the same on the Prophet-6, and it would seem that Robertsthebruce has a faulty unit.

[Robot Heart]

It's not a faulty unit, the issue has been described in detail. It is due to the way the filter and the oscillators are harmonically tuned. It is possible to have some stepping between semitones when doing very slow sweeps manually. If you turn the knob at a reasonable speed you will not hear it.

[Sacred Synthesis]

Is this the case even when no resonance is used?  We all expect the "stepping" of harmonics as you pass through the filter's range with a high resonance.  And does the high pass filter also have this issue?

[Robot Heart]

If you are used to any of our other instruments, the Prophet-6 behavior is identical.

[blewis]

Then what is the issue here?  The Prophet '08 filter sweep - however you do it - is as smooth as butter.  I use it constantly, always by the modulation wheel

If you always use the mod wheel for Prophet-08 filter sweeps, that may be an indication of what the difference/issue is. You can't manually modulate the filter with the mod wheel on the Prophet-6. You can only adjust the depth of an LFO modulating the filter.

Again DSI/Sequential, give us a DC 0Hz setting for the square LFO and you'll be able to tell customers they can sweep with the mod wheel.

Or, maybe intimate knowledge of the design informs you that this is not a workable solution? I'd be interested in knowing.