Audio-GD Master 19 in the house (ignore the MCRU LPS on the right, yes that is supposed to be a led blocker)
My first impressions of Audio-GD Master 19 vs. Massdrop THX AAA™ 789 headphone amps as promised:
Soundstage, especially height, more spacious and natural with M19. THX 789 soundstage in comparison is compressed and seems to be limited to left-center-right with space between somewhat hollow. The most vivid first impression was the first song I played with M19 and thought to myself that this is the most speakerlike sound I have ever heard from traditional headphones without crossfeed technology.
THX 789 emphasizes leading edges of the notes, reminds me of NAIM speaker amplifiers quite a lot, decay seems unnaturally fast. M19 has more balanced approach making listening experience more relaxed (not boring).
M19 has better distinction and more natural timbre with instruments and vocals. THX 789 makes every cymbal sound the same.
THX 789 has punchier bass but on some records it feels almost forced. Again M19 sports more variation and detail retrieval of lower registers seems to be couple of notches higher.
With M19 even in studio recordings it feels like you are listening in a natural lifelike setting. There is more space around the instruments and overall sound is effortless. THX 789 is almost like listening in a laboratory rather than a studio or live gig.
EDM is where THX 789 shines, probably because there is no reference to how different artifical samples are supposed to sound like. M19 can't reach the same level of "urgency". Still undecided if M19 is slow or that I have gotten used to THX 789 sound (probably the latter).
Overall for around €1000 with 10 years manufacturer warranty I am completely ecstatic about this purchase. The external build quality also surprised me. This monster doesn't picture that well but doesn't look out of place at all in my main rig.
The feeling that I would missing out too much when forced to swap from speakers to headphones with the same front end is finally gone. Mission accomplished!
edit: I checked Filip's preview video after my writeup and have to add that I agree with his impressions about dynamics as well. Compared with THX 789 this is another standout and easy victory for the M19.
Associated equipment used in comparison
headphones: MrSpeakers Ether Flow 1.0 with Forza AudioWorks Noir Hybrid HPC (Furutech XLR 4-pin)
sources: Simaudio Moon MiND 180 (streamer) + MCRU LPS via Lifatec TLTLG-OS (optical) & Oppo BDP-103 (media player) via UIT Audio DMP-RCA (coax) to Burmester 052 (dac, also Pure Class A)
interconnectors: UIT Audio IMP-RCA interconnect cables from dac to M19/THX 789 AAA (RCA unbalanced connection, dac has only one set of XLR outs unfortunately)
power: AudioQuest NRG-Y2 (THX 789 AAA), Shunyata Diamondback (BDP-103, M19 & Moon MiND 180) and Siltech SPX-800 (Burmester 052) power cables via Burmester 038 power conditioner with Shunyata Copperhead to wall outlet
audio sources: .flac files stored on a NAS drive & blu-ray concert lossless .m2ts files (LPCM Stereo) played from a USB thumbstick with full 24bit resolution (optical blu-ray discs limit to 16bit via coax due to copy protection)