4ms Phaseur problem - no effect, thumps

[T113]

Hi, this is my first post.
I'm no EE, but I can read and follow instructions, and solder fairly well.
Just finished my first Phaseur.  Used PCB from generalguitargadgets.com.
Leds all light, respond to speed and height.  APPEARS to work.
No phasing, clean guitar comes through fine.
Thumps at top and bottom of wave.  It APPEARS to be just before the led's fire.
Had to substitute yellow rectangular LEDs, mouser was out of red.

Any ideas/experience?

[T113]

*nudge*

[(doug harrison)]

It sounds like something simple with your pedal, like one component value or a couple of wires in the wrong places.

-check all the components (especially the resistors) around the input and output transistors.

-check that the input and output capacitors match the schematic or the diagram. Negative leads go toward input or output, whichever.

-recheck all the wires (input and output could be mixed up)


From your description, it sounds like you're almost there.

[T113]

Bump.

Checked everything, even built a second phaseur.  Both do it.

What would happen if the rectangulars were too bright?

(I used yellow from the same mfr, mouser was out of red.  The yellow have a much higher luminosity rating)

[(doug harrison)]

I don't know. I've had more success with power supplies than batteries on that pedal. I think the brighter LEDs would only effect the Height, and you would have to set the Height trimpot differently for different LEDs, but it could be that they're drawing more current and contributing to the thump. One thing I would try is to solder a 100 uF (16V or higher) electrolytic capacitor right across the power rails of the bottom TL074. The LFO is on the bottom of that chip, and some LFOs are known to cause thumping. (Read the current thread on 'Anderton Clicking Trem'.)

[ethrbunny]

Make sure you have the 'in' and 'out' wires from the switches going to the correct jacks. That would give you a working 'clean' sound with no effect.

[T113]

Thanks for the replies, guys!   

Using a godlyke PA-9 power supply.

I'll perform a septiary check (is that even a word?) of the switch/jack wiring.
I must confess, in my frustration, I clipped the pots and jacks from the first non-working one, so the problem COULD have followed me.
I've been doing PC service for 13 years... I should know better than that.   

[T113]

Oh god, I feel stupid. 

Got it working.  I have a flourescent light on a moveable arm over my workbench, like many of us do.
Ok, so I get the 'phaseur_big' diagram, and a magnifying glass w/a single-convex lens set on top of it for max magnification (think low-fi microscope).
I put the light under the phaseur guts, pointing up, board trace-side up, and start hunting. (so I can see through the board).
Next to the 'bottom' TL074, to the left, is the 'Speed 2' wire connection.
To the left of that is a 330 ohm resistor.
I had the TINIEST, speck-on-a-fly's-butt bridge between that and the .01mf cap just north of it.
I get mad, I've checked trace literally a dozen times.
So I pull the other phaseur I tossed aside out of the 'to do' pile.
It's got the same bridge.

Grrrr.     "I are a tek-nissian"

Sure does sound watery!  Not looking forward to the ring tweak, I set the 'siren' off earlier, scared the crap outta me.
But anyway, thanks to those who contributed.