[sdiy] Moog Source based LFO + SYNC

[Julien Delgoulet]

I think I found a way to do it but only "partially". I still have to work on this.
The idea is to use a FET to discharge the capacitor. It seems to work when I apply a negative voltage on the FET circuit.
So the solution might be to create a negative pulse that will transform  the FET as a closed switch discharging the capacitor rapidly ...
Now I have to create a circuit that creates this negative pulse and test this ...

I didn't study the yusynth VCO (http://yusynth.net/Modular/Commun/VCO/VCO-sch.gif) but it looks like this might be the solution ...

Julien 


Le 13 juil. 2010 à 12:15, Tony Kalomiris a écrit :

> Hi Julien,
> 
> Study the way VCO sync is done on this and other synths and especially the Arp Odyssey LFO keyboard reset circuit and you'll get an idea.
> The Arp service manual has a description of how this is done on the Ody.( I think)
> 
> 
> Tony Kalomiris
> 
> On 2010-07-10, at 2:59 PM, Julien Delgoulet wrote:
> 
>> Hi all,
>> 
>> First post to the mailing list ... so pardon me for the noob questions that can come in the next few days ;-).
>> I'm designing an LFO based on the Moog source schematics.
>> Everything looks good and works fine but I would like to add a SYNC input to it and to be honest I have no clue on how to do it ...
>> 
>> If someone's got an idea ... that would be awesome !
>> 
>> thx
>> 
>> Julien
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>> 
>