That's good to know. It would be interesting to see some actual impedance measurements of the stacked Advents. I did not have such luck driving my Revel F228Be's with Aegir mono-blocks. While the "sound quality" was very good , the Aegirs would "shut down" when presented with higher amplitude bass transients. The Revels drop to 3.42 Ohms at 98 Hz, so they can be a challenge. That being said- the Aegir in stereo mode drove the F228Be's without incident, but Aegir did sound a bit anemic driving the F228Be's. Schiit was aware of the impedance of the Revels before I bought the second Aegir. They came through on their end and provided a full refund when I returned the Aegir amps. I will say that I was sad to send them back, because they sounded very very good!I drove a stacked pair of Advents (OLA) no problem with my Aegir’s run monoblock. Impedance of the stack probably dips below 4 ohms at some frequencies. The stacked Advents sounded fantastic and were somehow competitive (except for rolled off highs) with my ADSL1230s and my JBL L100t’s.

