splitter cable I made causing feedback, needs a diode?

[pricey]

I made a splitter cable so that I could hear my clean tone at the same time as my fuzz tone, looking back it could have been designed significantly better.

When I plug it in it certainly works as I want it to, and I can get a lovely balanced wet/dry mix just by changing the level on the fuzz to my liking, but when I am not playing, it creates a horrible loud whistling feedback.

The cable works as follows:



...........FUZZ.......
..........>....<......
..........|....|......
AMP <----------------< BASS



So basically, my signal gets split before the fuzz box then re-mixed with the clean afterwards.

I guess the reason I'm getting feedback is because distorted output from the fuzz box simply flows 'backwards' down the wire back into the input of the distortion.

Am I right in thinking that a 'diode' is what i need here to ensure current only flows in one direction? Where in the circuit should it go?

Thanks.

[Jazz Ad]

Yes, that's a marvellous feedback loop you made there.
You need buffers to prevent this phenomenon. A single diode isn't going to fix the issue since you're dealing with AC currents.
The simplest way to achieve this is to use a blender such as a Boss LS-2 or any other.

[HogieWan]

A diode would work if you were working with DC, but an audio signal is AC

[pricey]

Right, thanks. At least I've learned from this experience!

[TheBassBloke]

Originally Posted by pricey

I made a splitter cable so that I could hear my clean tone at the same time as my fuzz tone, looking back it could have been designed significantly better.

When I plug it in it certainly works as I want it to, and I can get a lovely balanced wet/dry mix just by changing the level on the fuzz to my liking, but when I am not playing, it creates a horrible loud whistling feedback.

The cable works as follows:



...........FUZZ.......
..........>....<......
..........|....|......
AMP <----------------< BASS



So basically, my signal gets split before the fuzz box then re-mixed with the clean afterwards.

I guess the reason I'm getting feedback is because distorted output from the fuzz box simply flows 'backwards' down the wire back into the input of the distortion.

Am I right in thinking that a 'diode' is what i need here to ensure current only flows in one direction? Where in the circuit should it go?

Thanks.

Hey man,
We'll because you're using Audio signals, which as you may or may not know are waveforms, you're dealing with alternating current. Diodes only with with DC where the current is flowing in one direction :P

best way is to probably just buy a line selector, or maybe ground it..? I would just go for something simple like that beige boss thingo. ls2 i think? Or the xotix x, pretty much the same as the boss, but sexierrrrr

[niftydog]

Originally Posted by TheBassBloke

Diodes only with with DC where the current is flowing in one direction

Semantics, I know, but diodes do "work" with AC signals, but they do strange things to them.

[Jazz Ad]

At least they don't work to prevent feedback, which is our concern here.