vero board and bypass problems...

[AndrewH]

Hey guys, so I built this effect, it worked great...I  built one on vero board, it worked great too.

I then tried to add a bypass with a DPDT switch (just a standard bypass, not millenium) and the problems started.
The signal still gets through, and the bypass works, however there is a high pitched hum, even when bypassed, what's more, this hum increases when the gain pot is adjusted, even when bypassed.

if I touch, or earth the output (or the lug on the gain pot) the hum disappears.

I think that what is happening is that some of the signal is going back into the circuit and not the output? is this likely? should I then include a large resistor at the output of my circuit, into the bypass? is this a buffered bypass?

Has anyone encountered this problem?

I have made some adjustments to the components in the list, but I doubt these would cause such a problem.

I replaced the 1n914 diodes with 1n4148's
aslo, C2 is a 0,1uF, c3 is 27pF, c5 is 3,3nF

thanks guys.

[The French connection]

Hi Andrew! Is it boxed? Are you talking of Vero (stripboard) or breadboard? It sounds like you have a ground issue...check your wiring and watch the debugging thread.

Good luck!

Dan

[AndrewH]

nope, it's not yet boxed. I am talking about veroboard (strip board I suppose). I had built it on a bread board and then built another on the vero board. I am hoping it is a problem that goes away when I box it?

[cpnyc23]

My first thought is that you should chek your gain pot's ground connection for a cold solder joint.  Try reheating the connection and reflowing some new solder over the connection.  It sounds like the wire might be a little loose inside the solder.

-chris