I purchased both an ADI-2 FS and Topping D90 MQA over the last couple weeks. I have both running in but have spent a little time listening to each. My previous DACs were a SimAudio 380DSD (owned for 5 years) and then a Bricast M3 that I replaced the SimAudio DAC with before deciding to try some of the cheaper but well reviewed DACs like the two mentioned here.
So far my take on the RME is it is offers good detail without being overly forward or analytical. I wouldn't call it warm, maybe sweet and/or slightly laid back. I don't think I will get fatigued listening to it long term. My only reservations so far is it is a little lean sounding (at least compared to the SimAudio sound) and isn't the most dynamic. For its MSRP I think it offers a lot of value and very fine sound.
The D90 I find to be a different beast. It is maybe the most detailed DAC I've heard in my system, more like the M3 fed into my Pass amplifier direct bypassing my preamp. I also find it offers more dynamics and bass than the RME, again more like the M3. I find it also offers a little more fuller sound like what I was used to with the SimAudio, which is a quality I like and did miss a bit with the M3. I personally wouldn't call it lean sounding.
My reservations so far are I find it forward and/or a little sharp, with an analytical sound. I've noticed I've been listening at lower sound levels than usual because I find it fatiguing. I'm hoping that goes away over time, but if it doesn't I'm not sure I can handle it. I'm listening mostly to HD FLAC and WAV downloads that I'm very familiar with. Some of them are as good as I've ever heard, but on some I find it just too much...
Anyhow, I have 30 days to decide, and for $800 and all of the features it provides (e.g. variable volume, filter settings to play with, very solid construction, etc...) it is hard to go wrong for that price.
Cheers
