I find your impressions of various amplifier comparisons with and without the M2Z ZOTL particularly interesting. Your Benchmark amplifier has "vanishing " low distortion specifications. In my experience and understanding this is achieved via very generous use of NFB (negative feedback). This approach also results in a very low output impedance and conversely a high damping factor.
I’m curious how this type circuit will sound with and without the M2Z in the signal chain driving the Double Impacts and how sonically it differs from the LTA ZOTL 40. I look forward to your listening insights of these 2 very different amplifier topologies. I’m not sure if theZOTL 40 utilizes NFB and if so how much. Probably considerably less than the Benchmark given the distortion figures. I’m assuming that the ZOTL isn’t nearly as low. It would be very interesting if you had a zero NFB amplifier as a 3rd variable (SET or a First Watt). Yes,I know, easy for me to say 😊 Fun stuff.
Thanks,
Charles