VCO Mod Question
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VCO Mod Question

by izze on Sun Mar 18, 2012 5:50 pm

Hey Guys.
I am working on my new project, but came across some things that are not exactly clear to me.

I got a 2 VCO Mod, and i want to create a switch to Turn OFF VCO Number 1.
Also i want to add a VCO CV In to VCO 1 (which is IC11 Pin5 and the Point were R89,R90 come together).
How can a VCO CV In be added to the VCO 2 ?

Thanks for anyone who is willing to help
Patrick
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Re: VCO Mod Question

by guest on Mon Mar 19, 2012 4:57 am

im not to certain what the 2nd vco mod looks like
but im going to assume its a replica of the x0x vco
that mixes together before going to the vcf

if you want to shut off vco1
use a 3 position switch for the waveform switch
the middle is off
so no signal will go through

to add a cv in
use a switched jack
and connect the tip to pin5 of ic11
if you want to have slide on this input
connect a 100k resistor from the sleeve to ground
although thats a hack
and wont work under all conditions
to get a better slide youll have to install a switch
or use a switched jack that has more switches on it
either way
you want a 100k resistor in series with your cv
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Re: VCO Mod Question

by Altitude on Mon Mar 19, 2012 6:34 am

Just to add, they make a 3 position switch version of the stock two position switch that is in the kit. Thats what I use on mine and it works great.

For CV gate in, I used the existing CV/Gate jacks that are there and added a DPDT switch that allows me two switch them between in and out
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Re: VCO Mod Question

by izze on Mon Mar 19, 2012 9:53 am

Thanks for the Reply. where can i get this 3 Position Switch to replace my original one ?

@guest.

So on the 2VCO i connect the tip to IC11 (Pin 5) and ground to ground, and i should be fine ?

I am Planning to let the Waveform switch as it is, and make a seperate one just for On/Off. Do i have to cut a trace for that ?
Thanks guys
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Re: VCO Mod Question

by guest on Mon Mar 19, 2012 2:45 pm

the 3 position switch
is only needed if you want to replace the waveform switch
otherwise you can use a normal switch
and cut the trace after the waveform switch
this is the one that runs to r62

it sounds like the cv in is for the 2nd vco only
in that case
you can connect it up as you have said
although i would put at least a 1k resistor
between the tip and pin5
just to protect against over voltage
if you have the slide circuitry installed as well
then use a 100k resistor
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Re: VCO Mod Question

by izze on Mon Mar 19, 2012 2:54 pm

Ok thanks guest.

What exactly do you mean by slide circuitry ? Is this an extra mod should it be on the VCO already ?
So you would put a 1k resistor on each of the CV IN's (VCO1,2) or just VCO2 ?
Just as information i got the x0xsh0p 2VCO (substyler)

Thanks for helping me out once again
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Re: VCO Mod Question

by guest on Mon Mar 19, 2012 4:30 pm

ic12 and c35 implement slide on the x0x
so if these parts dont exist
then you dont have to use the 100k

if you are sending a second cv into the original x0x vco
then you should use the 100k
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