Tonight I’m working on building a simple A/B box so I can quickly swap between 2 guitars and and output.
The original crappy plastic box I’m using belonged to a stomp box prototyping breadboard but I stopped doing real projects a long time ago.
Basically I’m going to have some LED indicators, 3 jacks and a switch.
Wish me luck (I should be practicing)
Nice, interested in this idea
I had to redo that ground wire it was in the wrong place. Concerned about this old stomp switch it’s seen better days
Well at least I have a working a/b led switcher!
Modding this idea a bit. The plans I was using allow for a power plug or audio jack power (one light stays on)
I think I’m going to install a toggle though for power since this will be on my board.
Power off/on was a pain but I think I worked through my errors.
Onward to the audio signal switching!
A few levels of ugly on the signal soldering but everything is sound. Going to hot glue the LED leads and test
Well I think I need to consider my design a little more. When powered my active bass sounds great, there is a hum on the other line if the jack is empty or my passive bass is plugged in.
When I swap basses it goes with the bass.
The real trouble is I wired the off switch to the ground not the power wire.
What’s crazy here is with it off it’s got crazy noise but the passive bass has less and the active has more.
The design I didn’t 100% follow is using the 3rd set of switch nubs to do something with switching the grounds. I think I need to walk away tonight and tomorrow I’ll move switching to the power and add the 3rd row of ground switches.
I would gladly pay 10x for a bigger stomp switch those terminals are a real pain.
All in all it’s a successful test run. I just need to iron out the noise and we are golden.
Just thinking about this.
LEDs are nice- do you have them wired parallel to the output and what resistors are you using?
I also wonder if it would be possible to use an unpowered 3 way switch to do the same job?
So I have a 1k between power and LEDs and I put a 100k on both inputs between ground and tip. The design didn’t have one on output which maybe it should?
Power is just being used for the LEDs so it should work without.
I was wondering this morning how much shielding is provided by a standard metal box and if that could be part of the noise.
With power the noise is similar to a single coil guitar pickup so it’s not horrible but still.
Fun project I’m sure but did you know you can buy them for as little as $20?https://www.amazon.com/s?k=a%2Fb+switch+guitar+pedal&crid=2GOZP363JYYA3&sprefix=a%2Fb+%2Caps%2C141&ref=nb_sb_ss_ts-doa-p_2_4
Yea I know. The circuit is so simple and I had all of the stuff lying around anyway, I figured I’d give it a shot.
I suspect the commercial one probably has a bunch of shielding. If you think about it you are working with a very low unamplified signal (maybe a little preamp but not much more). the cables that will be coming in and out will all be shielded but none of the cables inside your box are shielded and if supplied with a DC adapter then it is likely to be quite noisy.
I’m no expert but just my thoughts based on my limited electronics knowledge.
FWIW this is the one I’ve had for years.
I just grabbed this one I was going to use it to split my looper pedal to a side chain but I think it can pull double duty since I’ll never use that looper pedal outside of practice.
Wow 
Cool project! You’ve already learned a lot, it seems!
You could extend the tabs on your foot switch with some extra cable, so you don’t have to solder at the switch but can use the cable instead, e.g. pull it out of the box etc.
Cheers,
Antonio
