I have a KLH TNE 7000 noise reduction unit. All those talking about the conversions might want to hear how this takes out pops and ticks. It works great on stero and sq. I haven't tried it on CD-4 yet, but as I understand the unit, it lets everything below 50-60-K pass thru w/o altering it, so I expect the carrier signal would not be affected.
Lance
Lance