[sdiy] Adding "sync" to a Through-Zero Sinewave Oscillator design

[Tom Bugs]

David - does your hard sync do as Don suggests "

the sync pulse should bring it to 0V, ascending.

"

I've always used this hard sync approach but the waveform can rise or 
fall from this reset point.

(sorry, straying off topic)


On 16/09/2018 07:45, David G Dixon wrote:
> The Intellijel Rubicon 2 is a through-zero VCO which I designed, and it has
> both kinds of sync.  We call them "Hard" and "Flip" on the panel, but I
> always think of them as "Reset" and "Reverse".  The Resetting sync is
> achieved in the normal way, with a JFET across the integrator capacitor.
> The Reversing sync is achieved by syncing to the threshold input pin of the
> comparator in the tri-square core.
>
>
>
>> -----Original Message-----
>> From: Synth-diy [mailto:synth-diy-bounces at synth-diy.org] On
>> Behalf Of Donald Tillman
>> Sent: Saturday, September 15, 2018 10:31 PM
>> To: ulfur hansson
>> Cc: synth-diy mailing list
>> Subject: Re: [sdiy] Adding "sync" to a Through-Zero Sinewave
>> Oscillator design
>>
>>
>>> On Sep 15, 2018, at 3:26 PM, ulfur hansson <ulfurh at gmail.com> wrote:
>>>
>>> I love the way traditional triangle core oscillator sync
>> sounds, and much prefer it to the harsher sawcore type sync.
>> with trianglecore sync (I hope I understand this correctly)
>> the waveform changes sign at trigger points rather than doing
>> a hard reset to 0v, right?
>>
>> There are several way to sync a triangle wave.
>>
>> The technically correct way would be to force the oscillator
>> to the start of the waveform.  So if it's advertised as a
>> sine wave, the sync pulse should bring it to 0V, ascending.
>>
>> I'll claim that reversing the direction of the wave is not
>> actually a sync.  The word "synchronize" means to bring an
>> oscillator to the same frequency, and same phase, as another.
>>   I don't think that's remotely possible by flipping the
>> direction of the triangle every cycle.
>>
>> I'd even call it "anti-sync".
>>
>> But if it's an expressive sound, it's probably worth coming
>> up with a better name.
>>
>>    -- Don
>> --
>> Donald Tillman, Palo Alto, California
>> http://www.till.com
>>
>>
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at synth-diy.org
>> http://synth-diy.org/mailman/listinfo/synth-diy
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at synth-diy.org
> http://synth-diy.org/mailman/listinfo/synth-diy
>

-- 
BugBrand LTD
UK company No. 07199808
VAT No. GB 988 2629 57
1 Ninetree Hill
BRISTOL BS1 3SB
United Kingdom
www.bugbrand.co.uk


---
This email has been checked for viruses by AVG.
https://www.avg.com