FET attenuator on CE-1 Chorus output. Any possible reasons why?

[maxdm]

I was looking at the CE-1 schematic and noticed that there's an OpAmp which boosts and rectifies the signal, feeding a Capacitor to ground, to get a control voltage, proportional to the input source.  The control voltage then feeds a FET that's placed at the output of the Bucket Brigade chip, which is connected as an attenuator for the signal output.

I haven't figured out if this is used as a noise reduction, for when there is no signal, or as a limiter, to duck the signal when there are peaks in the input signal.

[ElectricDruid]

Given the position *after* the BBD, it's pretty much got to be noise reduction, hasn't it? It'll gate noise off when there's no signal coming in.

If it was a limiter, you'd want it *before* the BBD to prevent loud input signals overdriving the BBD, which probably sounds terrible.