Splitting and merging signal

[manson]

I want to start my signal chain with an A/B box to split the signal into 2 separate paths. Next, the signal runs through various effects, say a fuzz in path A and a chorus in path B. Then I want both A and B paths to merge back together, and run into a last effect (delay), and into the amp.

For the merging part: can I just wire 2 (input) jacks into 1 (output) jack, simply by connecting the tips and sleeves of the three jacks?
The merge box should not be a mixer or blend control, because the 2 inputs will never have a signal on at the same time. It's not a parallel signal mixer.
It should something like a reversed a/b box, without a switch or any controls.

Is this possible, and what's the best way to do this without losing signal?

Thanks, Peter

[R.G.]

The proper circuit is a mixer, at least a resistive one. It's the only way to keep the two signals from fighting each other.

If you have two effects to meet and "join" to coin a word indicating that they connect to the same output jack without mixing, and both effects have a low-ish output impedance, then when one has a zero signal, it's output is not just not connected, it's actively trying to be 0V as hard as it would try to be the signal if it had one.  If that is simply connected with a wire to a pedal that has an active signal, the two effects fight it out for whether the output can be the signal or zero. You definitely lose volume and may introduce oscillation, distortion or other nasty effects.

The whole point in a mixer is that each signal can, to borrow a phrase, be all it can be without interference from the other signals, even if they're zero.

So you need a mixer. Active mixers give accurate mixing with no volume loss. Passive mixers always involve some volume loss, although this can be small if done right.

[manson]

Right, thanks for clearing that up R.G.

Looking at this mixer that you designed:
http://www.generalguitargadgets.com/diagrams/mixer_sc.gif

It should be as simple as possible, so can the pots be left out and the inputs directly connected to c1 - c4?