It has been a long time since I read Stereophile, but Sam's Corner in the February issue has a write up of the old Halcyon PVA and the Lightspeed Attenuator that I own. The article prompted me to put the Lightspeed back in my system for a whirl. I'm not regretting it. This opto coupler designed passive is truly remarkable. As usual careful system matching applies. I believe minimum amp Zin is 50k ohms and high sensitivity is best. Here is some additional information for anyone interested:
Lightspeed Attenuator
Single input/single output only. I have a version with dual attenuators. One of the designers comments is that this type of design removes the sonic effect of the switch from the equation.
Lightspeed Attenuator
Single input/single output only. I have a version with dual attenuators. One of the designers comments is that this type of design removes the sonic effect of the switch from the equation.