Further observations

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hamburgers
 
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Further observations

Post by hamburgers »

The x0x wobble (sample posted in "It just stopped working" http://www.ladyada.net/forums/viewtopic.php?t=861) only seems to happen when the resonance is turned all the way up, and at tempos between 85 and 140 bpm. I will be replacing the cutoff and resonance knobs both, but any other suggestions would be appreciated since my other thread turned into a jumper-related extavaganza. :?

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Post by guest »

it is possible that there is a loose connection
somewhere else in the power supply
the x0x draws more power from the 12v supply
when the resonance is way up
and the output voltage dips
this is what causes the warble sound

either the x0x is drawing way too much power
or the resistance in the power supply is too high

in particular check
r1
c8
r95
c28
make sure they are well connected and of the right values

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Post by hamburgers »

This is a new problem (the box has been working just fine save for a pot issue since December), and all the compnents are the correct values. I'll check those connections, though!

I started noticing it once I hooked it up again after rearranging my room.

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Post by hamburgers »

By the way, would those connections make it act funny just within a certain tempo range?

edit: checked em and they're all good. Guess I'll just have to make really slooooooooooooooow acid.

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Post by hamburgers »

bumping in hopes of a response to the last question

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Post by guest »

its possible that it would only happen
in a certain tempo range
the power supply filter is a low pass filter
so faster tempos wouldnt drain enough
current out of the capacitor to make
a significant voltage change

i dont have an epxlanation for why it would
stop warbling at a low frequency as well though

from experience though
my first 303 clone had an extremely pronounced
warble right within a sweet spot of tempos in the middle
but this was with a resonance mod

sorry i cant be of more help
this is a tough one to diagnose from afar
do you have an oscilliscope

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Post by hamburgers »

No sir, but I suppose I can alyways get a software oscilloscope.

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