Keeley Fuzzhead PCB Layout

liddokun · December 02, 2008, 10:34:44 PM

Now that I think of it, a tone pot would be useful. How would one go about adding a tone pot to this circuit? Any articles that could point me in the right direction, or perhaps a schematic and where to add it? I want to have the diode switching on stomp switch, as well as C3 on a stomp switch to switch between two different values, so it'll be easy to switch between sounds.

The last thing I want to do is that tone pot.
Any help would be great.

liddokun · December 05, 2008, 10:01:31 PM

Just a note, seems my layout has some part value errors.
R16 should be 10k, not 10R.
R11 should be 100K, not 199K.
Might wanna compare with schematic, I might have made typeos.

kurtlives · December 05, 2008, 10:13:28 PM

Quote from: liddokun on December 02, 2008, 10:34:44 PM
Now that I think of it, a tone pot would be useful. How would one go about adding a tone pot to this circuit? Any articles that could point me in the right direction, or perhaps a schematic and where to add it? I want to have the diode switching on stomp switch, as well as C3 on a stomp switch to switch between two different values, so it'll be easy to switch between sounds.

The last thing I want to do is that tone pot.
Any help would be great.

Search Mark Hammers Stupidly Wonderful tone control.

Imo though tone controls aren't that great in designs like these. I like the circuit with fewer controls as opposed to more...If you want tweakibilty I would stick with your input cap idea you were telling me about.

liddokun · December 05, 2008, 10:52:39 PM

Yea Chris, I think I'm going to stick with that one. The current production of this pedal does have an internal tone trim pot, but I find that on circuits such as these, it's fine without a tone pot. The guitar tone pot is good enough.

maerlma · February 20, 2009, 07:25:27 PM

has anybody verified this layout yet?

frank_p · February 21, 2009, 12:09:35 AM

Quote from: maerlma on February 20, 2009, 07:25:27 PM
has anybody verified this layout yet?

Yes I verified it, but I think only Nam built it.

liddokun · August 04, 2009, 09:56:57 PM

There seems to be some problems with my layout.
Mainly, that I should have added traces for a trimpot to bias the AC187.
Second, I can't seem to get the volume pot to work. It only works in reverse, and very small range. Anyone think they know why?

kurtlives · August 04, 2009, 10:18:27 PM

Quote from: liddokun on August 04, 2009, 09:56:57 PM
There seems to be some problems with my layout.
Mainly, that I should have added traces for a trimpot to bias the AC187.
Second, I can't seem to get the volume pot to work. It only works in reverse, and very small range. Anyone think they know why?

Did you try reversing the outer lugs?

frank_p · August 04, 2009, 10:20:25 PM

I verified it by comaring the layout and the schematics (on paper); not on the breadboard, neither build it with the layout. So I can't say that "mine" worked. I don't have any clue about why the potentiometer does not work...

liddokun · August 04, 2009, 10:46:31 PM

Quote from: kurtlives on August 04, 2009, 10:18:27 PM
Quote from: liddokun on August 04, 2009, 09:56:57 PM
There seems to be some problems with my layout.
Mainly, that I should have added traces for a trimpot to bias the AC187.
Second, I can't seem to get the volume pot to work. It only works in reverse, and very small range. Anyone think they know why?
Did you try reversing the outer lugs?

Yea, I tried that. It works now. Which means the schematic is somewhat wrong?

Now I just have to bias the thing.

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Keeley Fuzzhead PCB Layout