Maybe he means with "passive" the signal path - like in the Omnicraft GT-4A:
What a sophisticated power supply....nearly passive too.
If you really need one, since ages you can buy one here - hey, and you can choose beetween the GT-4:
http://www.ebay.com/itm/Omni-Craft-GT-4-4-Channel-Noise-Gate-Vintage-Rack-/170627125015#ht_522wt_609
and the GT-4A:
http://www.ebay.com/itm/Omni-Craft-GT-4A-4-Channel-Gate-Vintage-Rack-/170615156470#ht_571wt_778
BTW, its surprising that such a thing ever could be sold - just saying....