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Debugging my MOTM-101

2003-10-31 by Robert van der Kamp

Hi all, 

I completed my first 'real' kit yesterday, the 101, but I've 
got some problems with it, hope you can help.

When powering up the module everything looks fine, the led 
is blinking. Btw, I double checked all the parts and 
polarity, all looks okay to me.


Problem 1: two of the pads of pots VR2 and VR4 are placed 
close together. The pads of VR4 look connected on the 
pcboard printing. The pads of VR2 look similar, but there's 
a very fine line intersecting the bridge between the pads. 
Are the pads of both V2 and VR4 supposed to be connected? 
Or other pots as well?

Problem 2: Measuring the white noise output, I get no more 
than 0.69 VAC, even when the trim pot is fully opened. I'm 
expected to get 0.85 VAC. When listening to the white noise 
output, it is several dB less louder than the pink noise 
output.

The S&H output seems to work, but since it depends on the 
white noise output, I'll wait with that until I get the 
level fixed.

Thanks for any help,
Robert

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