[sdiy] pwming a tog

[Michael E Caloroso]

The Polymoog is a TOG based synth using Polycom card PER KEY to
implement PWM.  Each Polycom card a custom IC that included a
waveshaper.

MC

On 9/19/17, Mike HEQX <mike at heqx.com> wrote:
> Yes I did look at the flat keys piece recently as well as the dsp synth
> psuedo-tog which is $25.
>
> http://www.dspsynth.eu/
>
> This really interesting page
>
> http://www.armory.com/~rstevew/Public/SoundSynth/TopOctave/topdividers.html
>
> This article
>
> http://www.logosfoundation.org/kursus/2073.html
>
> and this
>
> http://www.narcisivalter.it/progetti/top-octave-synthesizer-5010.html
>
>
>
>
> On 9/19/2017 7:49 PM, Dave Garfield wrote:
>> Hi, all
>> While it doesn't do PWM, an English company named FlatKeys produces a
>> Top Octave Generator replacement for the classic synths and organs
>> which use a 50240 TOG.  This one isn't just a divider; it generates 12
>> separate top octave waves which are in tune, unlike the originals'
>> approximations.
>> It will also do vibrato, as it has a master clock. It can switch
>> octaves if desired, or transpose keys.
>> The price is £52.80.
>> I haven't tried one out, but have been meaning to for a long time.  If
>> anyone else out there has, I'd love to hear about it - warts and all.
>> Maybe it will work for you, or someone else out there.
>> FK50240 MK50240 <http://www.flatkeys.co.uk/MK50240.html>
>> I am NOT affiliated with FlatKeys in any way, shape, form or manner.
>> Just thought that this might be a good solution for replacing scarce
>> top octave divider chips.
>>
>>
>> 	
>>
>>
>>     FK50240 MK50240
>>
>> 	
>>
>> <http://www.flatkeys.co.uk/MK50240.html>
>>
>>
>>
>> On Tuesday, September 19, 2017 5:32 PM, Tom Wiltshire
>> <tom at electricdruid.net> wrote:
>>
>>
>> Because the standard TOG is based on dividers, you can’t add PWM. Run
>> any width pulse wave through a flip-flop and the output's a square,
>> after all.
>>
>> That said, there were some TOGs the produced 33% pulse waves rather
>> than squares (not sure exactly what the internals were to do that) but
>> there were none that offered PWM.
>>
>> If you had twelve ramp oscillators for the top-octave, you could
>> arrange ramp+squares to give you ramps at various divided octaves, and
>> then use those ramps to produce PWM, but it’d be a lot of circuitry,
>> and it’d probably get a bit sensitive. Have a search for “sub-octave
>> ramp wave” to get the basic idea.
>>
>> HTH,
>> Tom
>>
>> ==================
>>       Electric Druid
>> Synth & Stompbox DIY
>> ==================
>>
>> > On 20 Sep 2017, at 00:06, Mike HEQX <mike at heqx.com
>> <mailto:mike at heqx.com>> wrote:
>> >
>> > I wanted to do something with a TOG and I was hoping I could add PWM
>> to it. Not sure if you can PWM the master clock though, but that's
>> what I want to try. After all you pitch bend it that way.
>> >
>> > I not does that mean 12 pwm on the output of the tog?
>> >
>> >
>> > thoughts?
>> >
>> >
>> > Mike
>> >
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>