Author |
Adding a Frequency CV Input to the Yusynth/Oakley S/H |
br>defutura |
br>I like changing the sampling frequency/rate of the S/H live, but if I want to control it via CV I have to tie up a separate LFO that has an FM input and use that as an external clock. Which seems a shame, seeing as the S/H modules all have internal clocks...
I've looked at the different S/H modules available in MU/5U (MOTM101, Dotcom, Yusynth, Oakley), but none of these allow external control of the internal clock.
So, how difficult is it to add CV control of the internal clock to the Yusynth (or Oakley) S/H circuits?
For reference, here's the schematic for (what I assume is) the internal clock part of the Yusynth S/H:
Thanks! br> br> |
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br>Synthbuilder |
br> defutura wrote: | So, how difficult is it to add CV control of the internal clock to the Yusynth (or Oakley) S/H circuits? |
The Oakley is clocked by an internal VCO. Alas there was no space on the front panel for a CV input but it should be relatively easy to repurpose one of the sockets for voltage control of clock frequency. You'd just need to add a 100K resistor in there, which joins your new socket to the summing node for the VCO. The summing node can be found at the middle pin of Q1.
Tony br> br> |
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br>Troubleshooter |
br>Building a VCO around a single opamp is possible but the cirquit is too diffrent from the one you have allready.
Therefore the simpelest way to get to your goal seems to be a little dedicated VCLFO breakout pcb. Many cirquits available out there such as the simple 555 VCO.
I also built the Yusynth S+H noise combination. Use the internal clock for the drone/scifi sounds, and external clock for random clocked step filter effects etcetera. If I ever need to cv the clock I wouldnt mind dedicating one of my 2 VCLFO's. br> br> |
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br>defutura |
br>Thanks, Tony and Troubleshooter!
So it's that easy to add CV in to the internal VCO on the Oakley? Like this?
No need for any input/output protecting diodes or anything?
Some of the other threads I found on similar topics (i.e. adding CV control to any potentiometer) suggested replacing the potentiometer and its opamp with a little vactrol or opamp VCA, but this seems so much simpler... br> br> |
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br>Synthbuilder |
br> defutura wrote: | So it's that easy to add CV in to the internal VCO on the Oakley? Like this?
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Yes that will do it. Although I'd make the CV input socket normalised to 0V to minimise any interference when there's nothing plugged into it.
Tony br> br> |
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br>defutura |
br> Synthbuilder wrote: | Yes that will do it. Although I'd make the CV input socket normalised to 0V to minimise any interference when there's nothing plugged into it. |
Thanks. I'm not quite sure what that means in practical terms, though. Like this (I'm just feeling my way here...)?
Also, do you have any suggestion on where on the PCB I should connect this jack to 0v? br> br> |
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br>Synthbuilder |
br> defutura wrote: | do you have any suggestion on where on the PCB I should connect this jack to 0v? |
The normalising lug can be taken to 0V anywhere on the board - there's numerous spots to use. But pin 2 of the power header would be handy.
The sleeve connection of the socket can be taken to pin 3 of the power header. Pin 3 is also 0V but is reserved solely for the sleeve connections of the sockets. Pin 2 and Pin 3 are normally joined together at the power supply.
Tony br> br> |
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