Sorry I missed contributing to this thread since my post way back in January of 2018, when I first started running the M7-HPA amp. I have a thousand ish hours on them now and absolutely LOVE them. Zero issues, musical from day one, certainty no harsh midrange or treble and in fact I have been pushing speakers out into room and creeping a bit closer to side walls w no I’ll effect. In conversation w Richard he and Dean set some very ambitious goals for the smaller and much more affordable M5 amps. I believe they attained them. I can’t comment about 5a carbon driven by Pass other than to say I have deep respect for Nelson, his gear is always rugged and top notch. I still have a 400 A :-)
as to Quatros driven by a REF110, I have heard that and the M5 certainly should better it, a more direct comparison might be the REF150 se, Magic midrange like the 5
finally in filters, those of you using outboard high pass consider the model 7 high pass, better caps, more DBS juice and a non resonant case with WEL pigtails... I ran those w model 5a before getting the 7’s
have fun
enjoy the music
as to Quatros driven by a REF110, I have heard that and the M5 certainly should better it, a more direct comparison might be the REF150 se, Magic midrange like the 5
finally in filters, those of you using outboard high pass consider the model 7 high pass, better caps, more DBS juice and a non resonant case with WEL pigtails... I ran those w model 5a before getting the 7’s
have fun
enjoy the music