The address where I dropped off the Lyr turned out to be another Hifi store (HiFi Studio 79) that they are allowed to use as a pickup and dropoff point and where they display some of the Schiit products. So unfortunately, I couldn't speak to any of the Sonority Audio staff in person.
The owner of HiFi Studio 79 was a great guy, by the way. Already in talks with him about a 'regular' HiFi tube amp.
Sonority Audio had it running for a day and said they encountered no issues. Their technical guy had a look at it last weekend and to my surprise he couldn't find any issues either. They suggested it potentially was an issue with interference on the mains. But since I tried multiple locations in my house and multiple filtered power distributors (among which the one I run my studio equipment off of) I can hardly imagine that would be the case. One would expect that my powered monitor speakers and five other (hifi)-amps would also have a hum if there was a lot of noise on my mains; some of them run unfiltered and are far more sensitive.
They were supposed to ship the Lyr back to me last Monday, but since I hadn't received anything by Thursday, I dropped them an e-mail and they shipped on Friday. UPS should be dropping off the Lyr 2 this Monday.
Sonority Audio promised me that they would hold on to a new Lyr 2 and that they would swap mine for a new one should I still have problems.
From what I've gathered in my e-mail conversations with Ralph and data from the chamber of commerce, I think Sonority Audio is a hobby turned business. The company is registered at a residence in the Hague and run by a father (Ralph) and his son (Dennis). The adress in their letterhead and on their website is the aforementioned other hifi store (Hifi Studio 79) that is owned by someone else. I truly think they mean well, but they treat the company too much as a hobby and not enough as a business. This is apparent in everything from their communication (or lack thereof) to the lack of standard procedures for stuff like shipping, returns and defects. Each time I was the one that had to contact them to get things moving again, like they forgot all about me.
They are also the distributor for MrSpeakers in the Netherlands. I inquired about the Mad Dog Pro's and the Alpha Dog a couple of times during my e-mail conversations with Ralph, but got no response. I might buy them directly from MrSpeakers in the US instead as soon as the Euro appreciates a bit.
Again, I think they mean well, but they still have quite a ways to go.
In any case, I will probably be getting the Lyr 2 back tomorrow. I will keep you posted on how things work out.