Jimmyblues1959
500+ Head-Fier
I did the opposite.
I had the Piety in semi regular rotation with other gear but today took delivery of a Magni +
I bought the Magni + because I wanted the three step gain for better use with IEM and hoped the volume ramp was more linear than the Piety so in conjunction with the negative low gain option I would have more range on the pot with IEM. That proved to be the case and Magni + is definitely more IEM friendly, further assisted by the silent volume pot and slightly lower noise floor.
I have spent the last two hours back and forth between the two amps connected to a Modi + and using HD600 with both amps on high gain with a number of different songs streamed from Qobuz highlighting different vocals, instruments etc and to my ear the difference is quite slight. Slight enough where my faith in my auditory memory is significantly brought into question with the 10 seconds or so needed to swap amplifiers.
To my ear the Magni + is perhaps just a little dry by comparison, a little cleaner if you will. I noticed no glaring relative deficiency with the Magni + and just listening without thinking about the amplifier the Magni + is still very enjoyable to my ear, just marginally different.
I think perhaps the edge in detail goes to the Magni + it seems like that cleanliness comes off as a tad dry but enjoyable nonetheless.
EDITED TO ADD: The following day I listened with my DCA Aeon Noire. If anything the difference is even less pronounced, possibly due to the Magni + being fundamentally better suited to the higher current requirements of the low impedance and somewhat low sensitivity planars. The Magni + can drive the Aeon Noire to unsafe volume levels with no apparent distortion even on bass heavy tracks, the Piety would go into shut down protection long before a level that the Magni + can manage with apparent ease.
I still think the Piety is a great little amplifier but it isn't magic and for the moment it has lost its spot on my desk. It is in a cupboard nearby and is a 10 second swap so it will probably come out of retirement now and then.
Audio is a very subjective hobby. As long as the equipment you use allows you to enjoy music, that's what counts.