Hiss from VCO

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bcbox
 
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Joined: Thu May 25, 2006 1:30 am

Re: Hiss from VCO

Post by bcbox »

I just saw this one it sounds like you did everything ok.
The x0xi0 schematic might just make things more confusing because it's more specific to the kit itself. just do this:

waveform switch (middle pin)-------> \/\/\/\/-------->|(---------> mixer

resistor = 47k (anything 10k to 100k is ok)
capacitor = 1uF (-) side towards mixer

also, don't forget to connect the ground lead of the cable to analog ground on the x0x.
do you get the noise when plugging in to your mixer as well? or just your computer interface?

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isak
 
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Joined: Wed May 27, 2009 3:54 pm

Re: Hiss from VCO

Post by isak »

thanks Brian :)

i did what u said and its still with this noise.
i dont have a mixer i connect it straight to my sound card (RME)

i try to connect it from (-) of C17 and it was good no noise but very low volume like guest said.
as i said its only from the sqr wave not from the saw wave, the cable is ok.
i take my ground from here..
Image

guest
 
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Joined: Fri Feb 17, 2006 5:35 am

Re: Hiss from VCO

Post by guest »

that ground is only connected back on j7
so make sure the middle wire is still intact

otherwise try putting in the resistor bcbox suggested
or the pot i suggested
im guessing that youre overdriving your soundcard

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isak
 
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Re: Hiss from VCO

Post by isak »

middle wire on J7 is ok i checked it already.
i tried potting 100k resistor along with the 1uF like bcbox said and its still the same, with this noise.
when i say noise i mean when the x0x only powered up with the vco out mod, on sqr mode, no audio is on...only powered up.

guest
 
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Re: Hiss from VCO

Post by guest »

did you try the potentiometer

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isak
 
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Re: Hiss from VCO

Post by isak »

not yet, i dont have 100k pot here.
BTW the pot should be log or lin?

guest
 
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Joined: Fri Feb 17, 2006 5:35 am

Re: Hiss from VCO

Post by guest »

ideally it would be log
but you can try it out with a couple of resistors
try a 100k and a 10k
and just put them in series
and connect the output to the middle

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