Having Oscillation Problems, may Want To Read

Started by Zben3129, November 28, 2007, 10:49:35 PM

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Zben3129

Hi guys,

I built this as my first real stompbox (because of the breadboard layout, extremely useful!), and when I hooked it up, all I got was extreme oscillation. Oscillation is a kinda complicated thing to fully understand, but here we can simply refer to it as extreme feedback in the form of major hum and screech. At least it was for me. If you are having this problem, the first thing to check is ground.

Now I, being the newbie I was back then, assumed that you could just connect the ground of input and output grounds together and save a couple holes. This, as a matter of fact, turned out to be the problem. You MUST connect your grounds of input and output into the ground of the whole circuit.


Just figured I'd post it, even if it just helps 1 or 2 people  :)

gaussmarkov

Quote from: Zben3129 on November 28, 2007, 10:49:35 PM
Hi guys,

I built this as my first real stompbox (because of the breadboard layout, extremely useful!), and when I hooked it up, all I got was extreme oscillation. Oscillation is a kinda complicated thing to fully understand, but here we can simply refer to it as extreem feedback in the form of major hum and screech. At least it was for me. If you are having this problem, the first thing to check is ground.

Now I, being the newbie I was back then, assumed that you could just connect the ground of input and output grounds together and save a couple holes. This, as a matter of fact, turned out to be the problem. You MUST connect your grounds of input and output into the ground of the whole circuit.

Just figured I'd post it, even if it just helps 1 or 2 people  :)

hey!  thanks for this post.  i'll bet more that 1 or 2 people will benefit from it.  :icon_wink:

stkmtd

I think I may have the issue described here, but I'm a little confused as to what the OP's saying.

He says you can't connect input and output ground together, you have to connect them both to the common circuit ground.... but isn't that the same thing (they're still connected in either case)? Unless he means just twisting the ground wires together.

Quackzed

i think he means that you have to connect them ,not only to each other, but to the circuit ground as well. so that everything to ground is connected.
nothing says forever like a solid block of liquid nails!!!

Rawkcraze

still having oscillation.. maybe ill try putting it in an enclosure now and see if that grounds it better