Custom A/B Switcher
In my setup I required something that was able to mute my signal
and had either midi or a footswitch to control it. The dry sound from my
Mesa/Boogie Quad preamp goes through the this device to the
Behringer mixer. The mixer receives signals from both the Quad preamp and
the Digitech GSP2101. The switcher always passes the signal from the preamp through,
unless I need a sound that only comes from the Digitech. And for that I
needed a device that could mute the signal from the preamp. For a while I
used a Kitty Hawk Midi Looper, but this custom designed and built A/B
signal switcher can do the same for me and is much cheaper, but has no
signalloss what so ever (I did use Van Den Hul
cables) and it has absolutely no popping noise at
The idea is real simple. The small aluminium box has one input and two outputs, a adapter input and an input for the footswitch. The output of the preamp goes to the input, output A is connect to the Behringer mixer, output B is not connected and the footswitch is connectrolled by the Nobels MS-8 midi controller. Now if I don't want to hear the signal from the preamp I simply tell the midi controller to switch the custam a/b switcher to output B. Due to the special design the output that goes to the mixer is then switched to ground (with a resistor in between) and this makes sure that it's completely silent.
A friend of mine is an electronics technician and I asked him to design such a device for me. We talked the whole concept through and soon after built it. It's now in my rack and works perfectly. And best of all, it doesn't cost more then $25,- to built one, but it sounds and functions better then many devices that are three or for times as expensive. If you take your time you could even built one yourself, it's really not that hard.