Behringer A/B box is too noisey to use and isn't even an A/B box. Arghh!

[brett]

Hi.
I foolishly bought a Behringer AB100 A/B selector.  It was cheap (less than US$30), and looked ok, so I figured I couldn't compete with it by DIYing.

HOWEVER, it immediately gave me major grief.  For example, if I have a tubescreamer turned up in the "off" line I get a massive amount of hiss.  Maybe it doesn't ground the "off" line or something?

Another issue is impedance.  Nothing on the box tells you that it is a buffer, but it has 500k input impedance.  So I can't run my fuzzface after it.  Also, its low output impedance removes those subtle tonal qualities breated by particular combinations of output impedance and valve amps. (e.g. Rangemasters are very low output Z, Fuzzfaces are very high output Z)

I'm fed up with it.  As far as I'm concerned, it's useless.  I plan to yank the guts out (that'll be fun) and stick in some simple MOSFET switches so that it is just an A/B selector like it says on the box.

Ahhh.... that feels better....