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Software Instruments => DX7 V => DX7 V - Technical Issues => Topic started by: JayHurley on May 28, 2018, 04:21:40 am

Title: Pitch Wheel Note Inaccuracy
Post by: JayHurley on May 28, 2018, 04:21:40 am

The pitch wheel seems to move in quantized steps. If the range is set to 24, it is impossible to play a desired note using pitch bend midi messages, in many cases. Changes to the pitch bend value (-8192 to 8191) often result in no change in output frequency, then after some increase/decrease there is a step change. In my case, starting with a B2, midi note 47, then trying to bend to a G3(55) above it, there is no pitch bend value that gets close to the G3.

10923 is my calculation for correct pitch bend value to go from B2 to G3, but it comes up flat by at least a quarter step. Everything works great with Modular V3, very accurate.

Is this a limitation of the original DX7 hardware (which I do not own so can't test) or is this an issue with the soft synth?

Any help appreciated, I need this to be accurate in order to use the synth. I love the DX7 bigtime so I hope it's possible to fix.

Thanks!

Title: Re: Pitch Wheel Note Inaccuracy
Post by: Matt Arturia on May 28, 2018, 11:29:05 am

Hi,

Are you sure that the Pitch Bend Step value is set to 0 ?

Regards,

Title: Re: Pitch Wheel Note Inaccuracy
Post by: jeffbart on May 28, 2018, 01:54:35 pm

For me, when Pitch Bend Range is 24, and step is 0, there are audible quantised steps, a little finer than semitones, when using the Pitch Wheel. Try 'INIT VOICE" with Range 24.

ARP2600 on 24 semitones has smooth, non quantised pitch bend.

Using a Kurzweil SP4-8 controller. Pitch bend wheel from centre to full up, full down.

Title: Re: Pitch Wheel Note Inaccuracy
Post by: Matt Arturia on May 28, 2018, 02:20:08 pm

I wasn't sure so I checked with our original DX7, even with step at 0 you can still hear litle audible steps. Our software behaves the same so I'm guessing this is by design.

Edit : In fact, the real reason is because the original DX7 only has a 7-bit resolution and no smoothing. That is why you have audible steps.

Title: Re: Pitch Wheel Note Inaccuracy
Post by: jeffbart on May 29, 2018, 03:33:02 am

It's authentic!

Title: Re: Pitch Wheel Note Inaccuracy
Post by: JayHurley on June 25, 2018, 03:18:24 am

Just because we figured out the bit depth of the pitch wheel here, can I ask about the synclavier? It has >24 semitones in settings, but it sounds steppy... can you confirm whether it has full midi-spec resolution on pitch wheel or if it's limited? I love these sounds so much, and I know it's strange to require the full 14bit midi resolution, but so far I'm limited to the modular.