Hi TomFrei,

The paper you're referring to presents the source component with a 20K short to ground.  



Our amplifiers have an input impedance of 100K so they will work with tube preamps and or tube output stages, so really the last thing you would want to do is load the signal path with a 20K resistor to ground because it would drop the input signal voltage which in turn would reduce the volume of the amplifier.  Sonically it swamps transparency, and bogs down dynamics.

When stereo mono switches are installed in a ZSB, we don't present the source components with any additional load, we don't wan't you to hear the switch box!  What we do is put a 10K precision resistor in series with the signal so rather than lowering the impedance of the amplifier it's connected to, it actually raises it.  This also protects the source components from being shorted together by offering 20K of impedance between channels.



Thanks for asking!

Steve

Hi Tomfrei,

Please let us know how that amp sounds in a couple weeks!

Thanks,

Steve