Atari Punk Console help

Snuffy · October 28, 2006, 04:25:14 PM

I've built 2 identical atari punks that have the same problem.
They don't produce a constant tone, there's no sound. When I turn the pots they just scratch and squeak.

Do I have fried 556 chips? How would I go about debugging this... take a multimeter to the ic pins ..?

tcobretti · October 28, 2006, 05:03:58 PM

I would closely examine the pot wiring. It's weird and might produce scratches and squeaks if wired incorrectly.

Snuffy · October 28, 2006, 05:10:49 PM

I used this layout:
http://i49.photobucket.com/albums/f295/choklitlove/worthekik%20layouts/atarilayout.gif

On the two linear pots lugs 2 & 3 are connected which control the voltage
volume pot the middle lug goes to the output...

Yeah I'm pretty sure its wired up right.

coitmusic · October 28, 2006, 10:35:05 PM

Check your cap values...if these are too small, you'd be making very high pitched sounds, maybe too high to hear well.

Also, the voltage divider near the output seems to be a bit large. The orginal Mims schematc calls for only a 5k volume pot....so I'd try hooking the center lug of you volume pot to the junction between C3 and R2 and see if you hear anything more. Start with the pot turned all the way down!
Good luck!

coitmusic · October 29, 2006, 12:38:29 PM

Sorry, I meant bottom lug of the volume pot to the junction. A simpler way of saying it might be to take the wire from between R2 and R3 and put it between R2 and C3. (That came really close to being a good Star Wars joke.....)

Snuffy · October 30, 2006, 07:03:30 PM

I tried what was mentioned about the volume pot which did not help.
I've got voltage readings at each of the pins if those could help... I noticed I'm getting 0 volts at the output which seemed odd
Yeah, the cap values are small.. 10pf and 100pf... as in .00001uf and .0001uf... Thats what is specified in the layout.

Seljer · October 30, 2006, 07:09:47 PM

err, I see 10nF and 100nF respectively on most layouts/schematics

Snuffy · October 30, 2006, 07:13:32 PM

whats the n for then

Now I'm confused. I used .00001uf and .0001uf caps

Snuffy · October 30, 2006, 08:18:56 PM

Since I'm just some stupid 16yearold punk can somebody help me out here?
My knowledge thus far is that .1uf = .1 micro-farad or 10000

in the layout it says 10pf ...so that would be 10 pico/nano farads or .00001 uf

This is obviously wrong because my punk console doesn't make noise.
I touched some larger value (.01uf) caps in parallel and it did start making noise

So what caps do I need here?

$uperpuma · October 30, 2006, 08:48:15 PM

http://www.radio-electronics.com/info/data/capacitor/capacitor_conversion_chart.php

coitmusic · October 31, 2006, 07:36:39 PM

On the layout that you linked to it has the cap values as 10nf and 100nf also known as .01uf and .1uf.
10,000pf = 10nf = .01uf and usually labeled "103"
1,000pf = 100nf = .1uf and usually labeled "104"

your caps are too small and if you have a dog he now hates your new hobby

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Atari Punk Console help