Re: ADI-2/4 Prototyp
But I understand as per ASR forum that the 1st gen ADI is not powerful enough, especially with high impedance headphones?
Was just looking at the manual and it seems that an adapter won't make a difference for the Aeons; the RME simply can't push more current than about 250 mA
The ADIs show very high output wattage for high impedance headphones among the units tested at ASR. This should be obvious when reading (!) the reviews. Simple reason is that most units offer a max of around 19 dBu at 300 Ohms, but the ADI reaches +22 dBu (317 mW). Make that another +6 dB for the balanced Pro, a whopping 1.26 W, which is able to fry most of the high impedance models as they typically not stand more than 500 mW. To compare to some other marketing claims: that is 55 Volt peak to peak at the headphone output.
Then the obvious confusion about level and power. This Aeon user never got to 250 mA, he does not need more power, but has a level issue in his signal chain. I bet that he did not use the available +6 dB Volume as he feared distortion or noise. A quick look at the available level meters would have made clear that the output is far from max and the input level is far too low.
I do feel slightly called out! It's true I've shied away from testing the headroom before deciding to use my other headphone amp because I was worried about driving the ADI-2 into clipping, but I'm not sure I agree with this entirely.
Further to your comments, I've tested some songs and the level meters every now and then do come to close to max (even with software ReplayGain & EQ turned on) when there are very deep/low notes playing:
- Tsuyoshi Ujiki's "Dry Your Tears BGM" from Hokuto No Ken Soundtrack III (original 1986 CD) hits -9 dB peaks, but 0 dBr is quiet. I have to switch ReplayGain to "track mode" for this song (-1 dB peaks, highest I've ever seen) to become "loud," but not "loud enough," at 0 dBr.
- Tupac's "Hail Mary" from The Don Killuminati (original 1996 CD) hits -7 dB peaks and 0 dBr is just "moderately loud." Same goes for a couple of other songs from this album.
- Michael Jackson's "Thriller" from Thriller (first digital pressing 1982 CD with pre-emphasis) hits -3 dB peaks and 0 dBr is "loud," but not "loud enough" (pre-emphasis removed). Couple of other songs from this album also don't get "loud enough," just "loud."
- Hans Zimmer's "Imperfect Lock" from Interstellar (expanded edition 2020 CD) hits -2 dB peaks and 0 dBr is just not loud enough. Many songs from this album don't get higher than "moderately loud" at 0 dBr while hitting -2 dB peaks.
With the exception of the first song, the highest the level meter goes is -2 dB, so definitely not driving in first gear here. Yes, much of the time it is below -10 dB for the entirety of some songs, even with my DSP settings. Again, for most of the music I listen to, the RME works like a charm and gets plenty loud before I even need to push the volume to 0 dBr. It is just that 5% of the time that it simply runs out at 0 dBr. It was the Hans Zimmer music that made me decide to use my SMSL SP200 originally.
Again, I apologize for not having SPL data to quantify my subjective claims of loudness, but I take great care of my hearing and would not risk playing at levels that would be fatiguing except for one or two few songs at a time at most. This may or may not be helpful, but here's how I would describe different levels of loudness:
- "Quiet" is like overhearing music playing from a phone across from the room
- "Moderate" is like a normal conversation/TV listening level
- Moderately loud" is an enthusiastic conversation.
- "Loud" is watching a movie or playing music on my speakers at a "fun" level that's tiring after a few minutes
- "Loud enough" is like movie theater loudness, and not really fun except for a few brief moments.
"Loud enough" makes me cringe if it's any more than one or two quick hits in an otherwise quieter song. My headphones sometimes just don't get "loud," let alone "loud enough," especially in the low bass. It's not an issue with my hearing, because I am sensitive to those frequencies when listening to speakers (or even other headphones). As I suspected earlier, I'm not sure the 93 dB/mW specification for these headphones is correct.