Line Magnetic owners...how quiet are they?

518IA is a sweet amp, swapped in NOS tubes except for the 845s, very musical, holds bias well, no hum issues whatsoever. 

I had a LM-216ia. It was not quiet -- it had an audible hum with my Focal Aria 936's and eventually sold it because I could not stand the hum.

I also put it on a scope and measured it. The amp had low THD, but the noise was on the order or a few mV. The transformers had a resonance around 250kHz, which manifested itself in a lot of ringing and overshoot when I tested the amp with square waves.

My take on Line Magnetic is: their amps look cool, but I really did not like their transformers and the humming.

I own a 508ia and experience no hum whatsoever. I have read of the odd number of users who experienced this issue with LM amps, however not at a rate higher than I hear regarding other manufacturers.