I want to say right from the start that the Gustard X18 is a brilliant DAC! I am a fan of classical music and jazz and often attend classical music concerts. I've been using the cheap but fantastic Khadas Tone Board DAC for a few years now. My audio system consists of a PC, Khadas Tone Board DAC, Van Den Hul 3T The River interconnect cables, Marantz PM8006 amplifier, Canare 4S11 speaker cables and Graham Chartwell LS6 speakers. I've been looking for a replacement for Khadas lately, so I've been testing a few DACs in my system. They were the Cambridge Audio CXN V2 Network Player (sounds excessively fat, its stereo image is very blurry and lacks detail in the treble), Sound Carrier DAC Tube (sounds beautifully analog, but with muddy bass and veiled treble), SMSL D300 (has nice mids, but has shallow bass and veiled highs) and the TOPPING D90 III Sabre (has beautifully detailed mids, but the highs are very veiled, and the bass sounds very artificial, making a grand concert piano sound like an electric piano). Many of them were better in some ways than my favorite Khadas, but none of them reproduced the sound of acoustic instruments and large orchestras in a natural way.
And then, because of the reputation that Gustard has among my friends, I decided to try the Gustard X18 DAC. Already after the first beats of Stravinsky's Pulcinella, I knew that my Khadas had received a worthy replacement. The Gustard X18 sounds very neutral, has a very deep and authoritative bass, beautiful soft mids and detailed and open highs. A large orchestra sounds very natural, the stereo image is deep, clear and transparent, and the drum, cymbals and triangle sound clean and naturally sharp and have optimal volume. Brass instruments sound naturally shrill and raspy, while strings and woodwinds sound very faithful and have a great timbre. Orchestral highs sound powerful and authoritative with punches in the bass like I've never experienced before in my system.
I have no experience with expensive DACs like Chord Dave, Mola Mola Tambaqui, Nagra Tube DAC, DCS Bartok or Bricasti, but I know that the Gustard X18 sounds absolutely amazing for 669 EUR.
If you're a classical music fan and looking for a good but not too expensive DAC, grab the Gustard X18 while it's still on the market. Well done Gustard!