Another factor with SUTs is that the SUT will "step down" the impedance that the cartridge "sees" at the phono stage by a factor of the voltage gain squared.
So, for my set-up, at the 40 ohm tap, the gain is 10x the voltage (0.7mV to 7.0mV). My phono stage presents an impedance to the cartrdige of 47k ohm. With the SUT, the stepped down impedance is: 47k ohm/(10^2) = 470 ohm.
This works fine for my Stradavari, as Strats like between 250 - 500 ohms. However, if it did not, my phono stage allows me to use resistors soldered internally to adjust the impedance. The same calculation would be done on this altered impedance to determine the actual impedance the cartrdige sees:
Altered impedance with resistors/(10^2)
Likely that AirTight permits the same.
There are other SUTs out there that are more cost effective. The issue is the transformer windings, which if done less than perfectly can f****p your sound. Tim P is know to be anal retentative about his transformer windings. I paid for "insurance".
I rarely see used EAR gear on AudioGon - maybe satisfied owners??
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