Just made an account to share my experience and give you some feedback
about this amp.
context: I was looking for an airplay2 class d with enough power for peaks. HDMI arc is a big plus.
not much On the market as far as I know: the 2019 Sonos amp and the hk citation.
Speaker is a 3 way passive monitor rated 4 Ohms.
Dipping at 3.2ohms around 150-200 Hz topping at 32Ohms around 1.5kHz.
both tested with digital input hdmi and airplay 2.
after some times with the Sonos amp i can understand comments saying it is bright. This amp is very lean and lack some bass when listen at low level. I guess this could explain why loudness is on by default.
citation amp is much more composed and balanced.low to high and does not induce an overly bright sound
Maybe it is a bit too generous bass-wise.
end of comparison for now. Should you want some subjective statement feel free.
about the citation
on the plus side, sound was very good and clean. Like I didn’t need anything more. I wish I could have kept it but it will go back.
first, when played via AirPlay some piano key strokes provoke audible distortion. For example the very beginning of true Colors by Ane Brun. Le canon de pachelbel by Pierre-Yves Plat.
the issue is not present on the digital inputs. Tested via hdmi Apple TV 4k.
but I can’t justify this kind of work around.
second the volume control should be more linear. not enough steps. From step 3 to 4 is like more than twice the volume.
it certainly does not help that my speakers are 95dB/m/2.8v (or 92/1m/1w). Should be less of a problem for lower sensitive speakers.
third the random audio glitch
some plops and cracks appears. I could not specifically pinpoint what is the cause. Seems related to either a change of track or volume adjustment. This not repeatable. Aka random. at one point I was wondering if all of this was due to the axign processor not fast enough doing it’s thing.
last: the heat. When saying this amp should sound like a class A, I was not thinking it will go as hot as said class A.
this is winter. house temp is around 20 degree Celsius. After a good hour on a night session the amp is very hot. And I can hear a
fan going on for 2 seconds every 5-10 seconds. placing something under to elevate the amp helps. Best trick is to put it vertically on its sides or on its front. Case gets much cooler quickly and fan stays off.
Seems not enough time was spent on cooling system.
it is quite a disappointment when compared to the Sonos that gets barely hot with a passive cooling system.
or the citation amp does not go well with the kind of load my speakers are, and the Sonos is okay.
i checked with Harman customer support and they confirmed the amp should not be used with loads under 4Ohms. Not sur about that as I think manufacturers often stat this to avoid some claim.
i really liked the product on its core purpose: a (very) good sounding device. But there are unfortunately too much drawbacks at the moment.
hope it helps in some way. Really sorry to log in and being mostly negative toward a product. But I think I had to share.
maybe we’ll know more when one of you will do a proper review
thank you all for your participation on this incredibly valuable site
David.
edit: added load chart for the speaker.