Author Topic: Alpha Dog not clipping  (Read 499 times)

Droogie

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Alpha Dog not clipping
« on: May 14, 2017, 09:52:51 AM »
So I got the wiring issue solved and fired this thing up. Volume, gain and filter all work but I don't get any clipping! Weird!
I checked voltages and everything is spot on except pin 4 of the 308 (not metal can version) isn't absolutely o volts, same with gate of 5458—both are @4mV.

Any ideas where to look?
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madbean

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Re: Alpha Dog not clipping
« Reply #1 on: May 14, 2017, 10:18:03 AM »
You can consider 4mv to be 0v.

When you say no clipping you mean when when you turn the soft and hard knobs they do nothing? Remember in the center you will get no clipping.
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Droogie

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Re: Alpha Dog not clipping
« Reply #2 on: May 14, 2017, 12:09:30 PM »
Cool re 4mV. No distortion, hard or soft just clean signal affected by the vol, gain and filter controls. Nothing from hard, soft, or fat.
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madbean

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Re: Alpha Dog not clipping
« Reply #3 on: May 14, 2017, 02:17:48 PM »
Okay. A pic might be a good idea at this point.
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Droogie

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Re: Alpha Dog not clipping—now w/pics
« Reply #4 on: May 15, 2017, 08:51:08 AM »
Here's components:

Confirming that the pads marked "PWR" on the board are for .1u caps

Solder side is basically obscured:

W20k and W1M are in correct spots.
I reflowed parts under 6mm pots; still to do under 9mm pots.
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Droogie

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Re: Alpha Dog not clipping
« Reply #5 on: May 18, 2017, 06:38:54 AM »
So I swapped out the Germ diode and the BS170—both clipping knobs increase volume but still no overdrive or distortion. I'm a bit flummoxed.
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madbean

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Re: Alpha Dog not clipping
« Reply #6 on: May 18, 2017, 06:54:05 AM »
You have incorrect resistors in there. 470k instead of 470R. Not sure those are 2M2 resistors, either.
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Droogie

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Re: Alpha Dog not clipping
« Reply #7 on: May 18, 2017, 08:10:28 AM »
Yaaaaayyy. Just my stupidity! I'll take it! Thanks!
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blearyeyes

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Re: Alpha Dog not clipping
« Reply #8 on: May 20, 2017, 01:59:04 AM »
You have incorrect resistors in there. 470k instead of 470R. Not sure those are 2M2 resistors, either.

I hate it when I do that...
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I built peddles for Bat Thumbs car.

Droogie

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Re: Alpha Dog not clipping
« Reply #9 on: May 21, 2017, 10:26:24 AM »
Yeah, it's funny that a tiny, tiny factor of 1,000 makes a difference...
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hobbits71

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Re: Alpha Dog not clipping
« Reply #10 on: November 13, 2017, 07:31:33 AM »
Well. i made the same mistake with the 470k vs 470R resistors. The pdf still lists the 2 x 470k in the bom. So i assumed they had to be in there. I had no idea where the 1 x 470R had to go. But problem solved. Maby a good idea to change the document.

madbean

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Re: Alpha Dog not clipping
« Reply #11 on: November 13, 2017, 08:36:20 AM »
Sorry about that. I updated the project doc with the removal of the two 470k listed in the BOM.
I own madbeanpedals (duh). I am part owner of Function F(X).