A/B switch doubts

woj74

Senior member
Messages
153
Hi
The idea is to switch between two guitars and one amp. Looks like A/B switches are designed for switching one guitar/two amps- in/out/out. Do they also work in opposite direction in/in/out or it's a different thing. I got a spare DPDT stomp box switch and a spare box so could create such a switch following of diagrams you can find on web.
 

dbw

Senior member
Messages
4,531
The schematics you see on the web are made to keep things very quiet while switching.  If it's just to switch guitars between sets you can simply use the switch without any active components.
 
G

guitlouie

Guest
I think the typical a-b is made for in-out-out only, but there are products for what you sre trying to achieve.  Morley makes some nice routing pedals like this one:

http://www.morleypedals.com/dabc.html

that may be more what you are looking for.
 

dbw

Senior member
Messages
4,531
Screw that, don't spend an assload of money on what will cost you $10 to build from RadioShack parts.  You don't need fancy buffered switches if you're just switching between two guitars!

The blue parts and LEDs are optional, this is all you need!  Get a couple jacks from RadioShack and a box from Home Depot and away you go.  Don't use a battery with the LEDs unless you add switching jacks to turn it off.
 

woj74

Senior member
Messages
153
Thanks dbw, that's what i meant, three jacks one DPDT switch and a box and don't need to spend $100 on a simple switch. I also found such schematics. They refer to in-out-out mode. What do you think about them?
 

dbw

Senior member
Messages
4,531
Those will work in either direction, too.  The top one seems stupid to me, though... it's got a 3PDT switch, for one, and the LEDs use the same ground as the guitar signal, which means it could affect tone... for instance, if you use a wall wart to power it, it could add a hum to your signal.
 

woj74

Senior member
Messages
153
Your optional led indicator seem to be permanently connected to the battery, think would be possible to use one stereo jack to disconnect battery. I almost know how to do it but not sure wouldn't like to short-circuit anything. Can you update your drawing with that option? Your drawing switches hot wire only and drawing i attached seem to switch both hot and ground. Am i right? Is it enought to swich hot circuit only? Thanks again dbw for your help
 

dbw

Senior member
Messages
4,531
I will draw you a new diagram later... I can't think of any reason you'd need to switch the ground as well.  Maybe Jack or Dimitri can?
 

DiMitriR33

Senior member
Messages
604
woj74 said:
Your optional led indicator seem to be permanently connected to the battery, think would be possible to use one stereo jack to disconnect battery. I almost know how to do it but not sure wouldn't like to short-circuit anything. Can you update your drawing with that option? Your drawing switches hot wire only and drawing i attached seem to switch both hot and ground. Am i right? Is it enought to swich hot circuit only? Thanks again dbw for your help

it appears that the idea is to short the unused jack to ground. if switching amps it will kill some hum in the unused amp.
between guitars i doubt there will be any difference.
 

thumb55

Senior member
Messages
420
Tonebone makes a cool pedal (in theory) called the "Bassbone".  It let's you switch between 2 basses and one rig.  The idea being you might have an active and passive bass with different eq and gain adjustments.  Might work for a guitar?
 

woj74

Senior member
Messages
153
dbw, hope you'll find a while to update your drawing with battery save mod. Thanks in advance.
 
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