UglyFace Troubles

[gluedtogether]

I will plug in and check the gain, I did check and I do have a 1meg resistor.

Does it matter in the signal is going through the cap before its hits the resistor... I have been trying to compare the layout I am using back to the home-wrecker one and they seem to match up.
http://www.home-wrecker.com/uglyface.html

[Mick Bailey]

You need the resistor before the .1uf input cap.

[slacker]

Here's another thing you can do to try and debug it.

The LM386 stage if it's working properly is basically a booster/distortion, so can test whether this is working by disconnecting it from the rest of the circuit and plugging it into your amp. The easiest way to do this is to remove the wire from the wiper of the sensitivity pot and and disconnect the output jack from the volume control. Then connect the wiper of the sensitivity pot to the output jack. Plug it in and play your guitar though it, the sensitivity pot should act as a volume control and it should be loud.

 

[gluedtogether]

Thanks, the layout I am using has the cap before the resistor, I will switch that and see if that does the trick

If not, I will test the 386 section
thanks to the both of you

[gluedtogether]

I switched the resistor to be in front of the input cap. I am checking the layout against the scheme to see if there are any other parts not in quite the right order. So far , looks to match up

After the switch, I still can get the LED to light. I can get some usuable sounds, but only when the threshold is in on spot. Its very fine in its setting and stops working if I adjust at all.(produce pitched signal without guitar coming through) The frequency seems to have great response

Do I have the pots correct, all are linear beside the volume?

thanks

[Mick Bailey]

Pots are ok - it doesn't really matter if they're log or lin, it's the value that counts. The controls should have a fairly broad adjustment and give you a sound wherever they are set.

What was the result of Slacker's suggestion? Did you get audio output ?

If you could post some pics of your layout it might be helpful - solder side, wiring and component side.

Just one more thing, did you try a replacement 386?

[gluedtogether]

I tried a JRC386 and LM386

I tried slacker's suggestions and didn't get audio output. I disconnected the output from the switch and connected that to lug 2 on the sens pot but didn't get guitar through.

Let me know if the pics provide a good picture of what I am looking at.

Thanks again for following up with me






Thanks

[Mick Bailey]

From the pictures nothing jumps out, but it may be that you have a poor connection somewhere between a component leg and the soldered joint. To check this, test each component leg for continuity from the component side to the copper pad on the other side. You might need to extend your DMM prove with a needle or piece of wire to get to the component leg. I've had to do this on a previous build and it showed up a poor joint.

If you're not getting audio output, you might not be getting input either. You can connect your audio input directly to the input of the 386 which eliminates the input capacitor/resistor. Then use Slacker's suggestion to test for output. Just a thought here - what resistance value do you get if you meter across the input jack with nothing plugged in?

It may seem like an uphill struggle to get this working, but it will be woth it in the end. This has got to be one of my most played-with pedals. Once you get it working there are also some useful mods to play around with.