Years ago I came across a little DPA-published table online indicating noise floor and max SPL for 4060 and 4061 through DAD6001 at various reduced phantom supply voltages. I think I linked it here at TS somewhere. I've searched for it a couple times over the past couple years, locally on my HDD, here at TS and more broadly online, yet am unable to find it. Granted, it indicated phantom supply voltages, but some sleuthing with a DAD6001, a switchable 48/24/12V phantom supply and voltmeter would allow one to correlate actual measured supply voltage out of the DAD6001 with the noise and max SPL values from that table.