[sdiy] Question how to improve rotary encoder feel

[Tom Wiltshire]

+1 agree. That *is* pretty funky.

Tom

On 9 Jun 2017, at 22:18, paula at synth.net wrote:

> Roman,
> 
> ooo, I like!!
> 
> Paula
> 
> On 2017-06-09 15:02, Roman Sowa wrote:
>> That description is exactly what that pot is, I mean the picture
>> Julian posted. At first glance it looks like regular pot, but it has 2
>> wipers rotated by 180 degrees.
>> And here's my DIY attempt to make such pot from regular cheap dual pot:
>> http://www.synthdiy.eu/files/endlesspot.jpg
>> Roman
>> W dniu 2017-06-09 o 13:49, rburnett at richieburnett.co.uk pisze:
>>> The Ion pots are available from Alesis as replacement parts for repair
>>> work.  Perhaps you could buy one to play with, then see if there is any
>>> manufacturer's info on it to suggest if it's made by one of the usual
>>> suspects like Bourns, Alps, Alpha, etc...
>>> I don't have an Alesis Ion, but an engineer friend who has one explained
>>> the operation of the pots to me like this:
>>> Dual track potentiometers, except one track is rotated 180 degrees
>>> relative to the other track, and no mechanical end-stops so they can
>>> rotate continuously.  When the wiper for one track goes over the
>>> discontinuity in its track, the other wiper is in the middle of its
>>> track.  Some clever software is then used to read the voltages from both
>>> wipers and "hide" the discontinuities in each track by using data from
>>> the other track at that time.  You then get smooth high-resolution
>>> parameter adjustment with endless rotary control, and free from any
>>> glitches or mechanical detents.  That's the theory anyway, perhaps some
>>> Ion users can comment on how well it works in practice?  They've been
>>> around for a while now, so it would be interesting to know how well the
>>> well-used pots are holding up!
>>> I hope that explanation made sense.
>>> -Richie,
>>> On 2017-06-09 12:26, Julian Schmidt wrote:
>>>> I found 2 pics of the ION parts
>>>> http://studiorepair.com/gallery/Alesis/Ion/slides/Alesis_Ion_Potentiometer__STUDIOREPAIR_04032501_1510157530.JPG
>>>> http://studiorepair.com/gallery/Alesis/Ion/slides/Alesis_Ion_Panel_PCB__STUDIOREPAIR_04032501_1510087626.JPG
>>>> julian
>>>> Am 09.06.2017 um 13:17 schrieb Julian Schmidt:
>>>>> I'm all ears if you know a part number or source for affordable
>>>>> endless pots.
>>>>> All I can find are expensive industrial ones in the >10€/piece range
>>>>> and although being 360° endless rotation parts, the resistive taper
>>>>> spans only 340°
>>>>> The Ion pots look more like the normal, cheap 1-2€ pots but my
>>>>> research turned nothing up, yet.
>>>>> julian
>>>>> Am 09.06.2017 um 12:53 schrieb rburnett at richieburnett.co.uk:
>>>>>> You could look at using continuous rotation pots like the Alesis Ion
>>>>>> supposedly uses.
>>>>>> -Richie,
>>>>>> On 2017-06-09 11:30, Julian Schmidt wrote:
>>>>>>> Hello All,
>>>>>>> I have a current idea that could vastly benefit from using encoders
>>>>>>> instead of pots.
>>>>>>> My only gripe is that I never had an encoder where I liked the feel.
>>>>>>> With the standard 24PPR encoders you have to make way too many turns
>>>>>>> to get to a higher value.
>>>>>>> Rotationspeed based value speedups made the feeling even worse on the
>>>>>>> machines I tried. Also a lot of people complain about encoders on
>>>>>>> synths for the same reason.
>>>>>>> Best solution so far is something like on the midibox or AN1X where
>>>>>>> you push the encoder for fine resolution.
>>>>>>> The only one people seem to like are the Nord ones with the LED rings.
>>>>>>> I never had a nord machine in my hands, but Forum research suggests
>>>>>>> that they somehow managed to line up the LED movement on the ring with
>>>>>>> the encoder travel. So if you turn the encoder half a rotation, the
>>>>>>> value LED is at half, too.
>>>>>>> Any idea how they've done this? looking up the specs it seems like
>>>>>>> they are using Bourns ECW1D-C24-SE0049L encoders
>>>>>>> (http://electro-music.com/forum/topic-50251.html).
>>>>>>> 49L is not specified in the datasheet, but my guess would be 48L =>
>>>>>>> 48PPR which would still be too little resolution to even bring a 7 bit
>>>>>>> value up to full range in one revolution.
>>>>>>> Is the front panel resolution just reduced and interpolated on the
>>>>>>> nords?
>>>>>>> So if anybody has some hints how to give an encoder a more
>>>>>>> potentiometer like feeling I'm all ears. Especially if we talk 12 bit
>>>>>>> instead of 7 bit parameter resolution.
>>>>>>> For practical reasons encoders would be great for layered UIs to share
>>>>>>> a set of controls between multiple LFOs or preset saving. LED rings
>>>>>>> are sexy as hell, too. But whenever I use encoders for something other
>>>>>>> than menu diving and editing settings I wish for a pot in my hands ;)
>>>>>>> Cheers,
>>>>>>> Julian
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