a/b switch passive or active?

[teddybear]

what is the difference? which one will cut the sound?

[Processaurus]

You can make a good A/B switch with a DPDT switch, using the extra pole to ground the channel that isn't being used, otherwise its easy to get bleed, if its going from one source to two amps or whatnot.  The only plus of a A/B switch that uses electronic switching is that might be able to switch silently, like the FET switching in the boss pedals.   I was thinking of making a FET based A/B switch with a momentary footswitch, because every momentary switch I've tried as a simple passive A/B has made gross popping/crackling sounds.

[teddybear]

wew, nice explaination.
thx. do u had the schematic?

[dachshund]

Morley has an a/b/y switch, and they post the schematic.
It's pretty darn simple. I've read that it does bleed some, though.

Adding here as food for thought...
http://www.morleypedals.com/abyes.pdf

[The Tone God]

Just to be clear are you asking specifically about the actual switch mechanism being passive (mechanical) or active (solid state) or are you asking about whole A/B circuit signal path being passive (straight wiring) or active (buffered) ?

Andrew

[teddybear]

about using power/ transistor like.
not the mechanism. 

[soulsonic]

I very much prefer to use an active buffer with my A/B boxes, it guarantees no bleed through and lets you add fun tricks like polarity reversing. A good opamp works very well, and can do the job without messing up your sound, especially when used with a bipolar supply.