Anderton Wah/Antiwah vero

[jhlind]

I've drawn a vero for the Anderton Wah/AntiWah, complete with Bipolar power supply.

One problem - the op amp distorts badly when using the .001 and .005 capacitors, as shown on the original schematic.

Has anybody has this happen to them?

I've checked and re-checked the vero. It is correct.

Thank you for help in advance.

[joinpobob]

I breadboarded the circuit this evening. It works, kinda. I used the the .001 and .005 with no "distortion", but I get a hiss at all settings. When I rotate the pot, the hiss changes in tone and sounds like a wah. Is that right?

I have a layout on my blog. Check it out.

[DDD]

At the "extreme" settings of the 50k-L pot outputs of the TL072 OpAmp shortened to the ground through C2 or C4 capacitor.
This may cause high-freguency oscillation (hence hiss) and\or distortion depending on the type of OpAmp.
To avoid this put at least 2 kOhm resistors in series with the 50 kOhm leads or one resistor from the wiper of the pot to the ground.

[ralley]

I recently did a vero layout for the Anderton Wah-Anti Wah and converted it for use with a single +9V supply.  No issues with distortion with this running either with the original 18V bi-polar supply or modified for +9V.  My layout is in the gallery under http://www.aronnelson.com/gallery/main.php/v/diyuser/rob/ might be worth comparing to your layout OP.

This build does have issues with a scratchy sounding pot - I assume I'm getting DC on it, will try a blocking cap.  It also cuts out at either end of the pot, will try a limiting resistor as above.

Rob.

[joinpobob]

Rob,

Thanks for the chiming-in. I tried to look at your layout, but it just showed up as text. Is there a program that I need to open it with? Thanks.

[ralley]

Hi Ryan - yeah you need DIYLC to open the layout - I've uploaded a GIF version (still at http://www.aronnelson.com/gallery/main.php/v/diyuser/rob/) for easy online viewing.

Cheers, Rob.

[ralley]

Over in the pictures thread some guys asked for sound samples of the Anderton Wah-AntiWah, I've uploaded clips of mine to the gallery and linked to them from the Wiki: http://www.diystompboxes.com/wiki/index.php?title=Anderton_Wah-AntiWah.

Rob.

[jhlind]

I recently did a vero layout for the Anderton Wah-Anti Wah and converted it for use with a single +9V supply.  No issues with distortion with this running either with the original 18V bi-polar supply or modified for +9V.  My layout is in the gallery under http://www.aronnelson.com/gallery/main.php/v/diyuser/rob/ might be worth comparing to your layout OP.

Tried the vero build. Also got the high pitch when disengaged and pot turned to extremes. Will try the resistors in series.

HOWEVER, also got LOUD SQUEAL when engaged. Did this ever happen to you? Tried several op amps; all have same results.

[ralley]

No problems here with a loud squeal when engaged.
Rob.