Question about how A/B pedals work

[zeppelinfreak]

Okay, so I know A/B pedals let you switch between two lines. But if your amp only has 1 input, how do you turn it back into one line?

So if you have 2 inputs, or two amps, your AB would look like this

. Bass
. |
. |Line
. |
. |
. |
. /\
. / \
. / \
. | |
. Line 1 | | Line 2
. | |
. Amp

But if you have one amp with one input it would look like this


. Bass
. |
. |Line
. |
. |
. |
. /\
. / \
. / \
. | |
. Line 1 | | Line 2
. | |
. \ /
. \ /
. \/
. |
. |
. |
. Amp

My question is this. How are line 1 and line 2 coming back into one line to go into the amp?

Sorry if this is a stupid noob question

EDIT: Shoot, my diagram is messed up. Oh well

[bongomania]

An A/B box can do only one of two things: it can either send a signal to one of two different inputs, like one bass going between two separate amps; or it can switch between two instruments going into one amp. IOW there is no combining or re-mixing with an A/B box.

[Jimbob Jones]

+1

In most situations they're used for one of 2 things:

1. switching between two basses so you dont need to unplug one and plug in the other, you just step on the switch and it mutes bass 1 and lets the signal from bass 2 through, and vise versa.

2. switcing between an amp and tuner: stepping on your AB box cuts the signal going to the amp and sends it to the tuner so you can tune up in silence and then pressing the switch again cuts the signal going to the tuner and sends it to the amp.

          A
         /
in/out -<                  it's as simple as that really!
         \              <- the switch just swaps between A and B, 
          B                hence the name.

[Jazz Ad]

To recombine signals you need a line selector.
These days the LS-2 is pretty much the only one on the market.

[zeppelinfreak]

So hold up. The A/B switch is actually turning the 2 lines into one? Not splitting one line into 2?

**** son, I got a LOT to learn about effects.

[niftydog]

No, and yes. A simple ABY box will do BOTH, but not simultaneously.

[bongomania]

Either/or of those two options, but never both at the same time (unless the unit at hand is more than just an A/B).

[zeppelinfreak]

Ok, I think Im starting to understand. So youd need one A/B to split the line, and another one to turn it back into one line?

[baalroo]

Originally Posted by zeppelinfreak

So hold up. The A/B switch is actually turning the 2 lines into one? Not splitting one line into 2?

**** son, I got a LOT to learn about effects.

actually it's either or... you can run the signal either direction through the thing. it can split a single Input into an A output and B output OR you can literally hook it up "backwards" and it can split Input A and Input B into a single output. In simple terms,

If you want a something that basically let's you switch between two different "chains" of effects but only are using a single bass and amp then what you want is a 2 Loop Bypass Looper, not an A/B box.

The easiest way to initially think of a Bypass Looper is basically an A/B box that also recombines line A and line B all in the same box.

[zeppelinfreak]

Okay, I think Ive finally got this A/B thing figured out.

Dang, I can understand the mathematics behind fuzz, the technical intricacies of a phase shifter, but not a simple A/B switch.

[bongomania]

Originally Posted by zeppelinfreak

I can understand the mathematics behind fuzz, the technical intricacies of a phase shifter

Please don't take this the wrong way, but those are funny things to say. As a pedal freak who does DIY electronic work, I would not think of math relating much to fuzz, nor would I claim to have fully grasped the technical intricacies of phasers.

IOW I'm either impressed or chuckling... Don't know which yet...

[zeppelinfreak]

Originally Posted by bongomania

Please don't take this the wrong way, but those are funny things to say. As a pedal freak who does DIY electronic work, I would not think of math relating much to fuzz, nor would I claim to have fully grasped the technical intricacies of phasers.

IOW I'm either impressed or chuckling... Don't know which yet...

I just like to exaggerate. I just understand that fuzz clips the sine wave, and the basics of the phase shifter. Then I use big words.

[bongomania]

Fair enough. Me too.

[niftydog]

Originally Posted by zeppelinfreak

Ok, I think Im starting to understand. So youd need one A/B to split the line, and another one to turn it back into one line?

Well, kinda, but I don't think anyone really does it that way because you'd need three legs! The common way is to use a mixer to recombine the signals. The other way is to use a Boss LS-2 (or similar custom design) which effectively is a box with two integral effects loops, but only one input and one output.

[Vic Winters]

This is how an ABY (Morley) is wired. If you have knowledge of DPDT switches, you'll get the idea.

[Jonyak]

Originally Posted by bongomania

Please don't take this the wrong way, but those are funny things to say. As a pedal freak who does DIY electronic work, I would not think of math relating much to fuzz, nor would I claim to have fully grasped the technical intricacies of phasers.

IOW I'm either impressed or chuckling... Don't know which yet...

http://en.wikipedia.org/wiki/Fourier_transform

have fun... there is actual alot about fuzz that can be represented and modeled mathematicaly.

also with some basic background in electronics or physics the technical intricacies of a phaser are not to daunting to understand.

http://en.wikipedia.org/wiki/Phaser_%28effect%29

[bongomania]

*ego bristling* I was oversimplifying my position in order to point out the humor I found in his exaggerated statements.

[Jonyak]

Originally Posted by bongomania

*ego bristling* I was oversimplifying my position in order to point out the humor I found in his exaggerated statements.

Ya I found it funny that he knew all that really technical stuff but not a switch... anyways...

A/B/Y great things if you have 2 basses, or 2 amps...

what I want is a 4 in 1 out switch. I have been thinking of making an isolated switch box that would do that. I would put a small amp in it set to unity gain to act as a buffer.

[bongomania]

Eminently doable. Check out the Lehle 3@1 for a good example of a 3-in 1-out with useful extra features, as food for thought for your 4@1 build.