Apocatastasis (feedback return for cheap digital delays)

Step 2 Schematic

The schematic is really simple though it was a little challenging to get the idea working at first. Basically you are splitting the output and building a passive mixer for the input. I started with a 10k resistor on the instrument input but there was too much of the output mixing in, so i switched it to 1k and that solved the issue. I also found that when the feedback was way off in the weeds (pot turned all the way up) there was a really high pitch every delay and that sucked. putting in the cap solved the issue and after using it for a few practice sessions now i'm happy with it.

Comments

[rathergood]

Thank you for your quick reply. As far as ground goes for a pedal like this, how do I connect them all together? The only circuits that I have ever made I have used a 9V battery, so it was simple to understand where all of the grounds went to. For this, my intuition kinda goes out the window. Thank you for your patience.

[pstretz]

I connected the sleeve terminal of each phone jack and plug to the GND terminal of the potentiometer. If you look at the assembly pic on the next step, you can see the black wires, these are GND. The sleeve on the two phone plug cables are copper, they are also in the bundle.

[rathergood]

I'm a bit new to electronics so I have a few questions. On all the jacks (or jacks/plugs in your case) on your schematic you only have one wire going to it, which I am confused about. Is there some invisible standard that I don't know about, like all the grounds are hooked up to a specific place. I tried figuring it out with the picture, but it isn't quite clear enough to see every connection. Also, just out of curiosity, at a components/conceptual level how/why does this circuit create feedback? Thank you, any help and/or clarification is appreciated

[pstretz]

Oh man, have I so been in your shoes. :) Sorry for not being specific. The sleeve on all the jacks go to ground and they are all mono jacks. This is a pretty standard thing to do. If you look at guitar pedal effects the sleeve on the jack goes to ground about 99% of the time. As far as how it creates feedback, see my reply to A Good Name on the first page, should be right below this reply. It may not be the feedback your thinking of, but this feeds the output from a pedal like an echo or delay back into the input to go through the effect again. Cheap delay pedals seldom have a feedback knob on them anymore. Hope that helps.