Help understanding the ROG Fetzer Valve versions

[mordechai]

There is a lot of information on the ROG sit regarding their Fetzer Valve.  I built the original version and it sounds nice, but I am curious about how the "high gain" version would really function differently.  In that version, the 1M resistor to ground comes before the series resistor, which is lowered to 33K.  This, according to the site, yields much higher impedance...does this allow more dynamic range from the input signal and therefore does it yield a bit more gain?