I own a Topping D70S since March 2021 and over the following months compared it vs other dacs, some owned and some borrowed, including the Topping D90.
Some background and context.
I bought the D70S having being adviced by a friend, who designs and builds top level tube amps. All the tests and comparisons have been made both blind and "subjective", with matched levels and same test tracks (I can provide the list), in my friend's reference system (Bladelius Embla server/dac, 4 chassis tube pre + power, Avantgarde speakers) and my personal system (Macbook Pro/Audirvana, MBL custom pre + power, Dynaudio Special Forty speakers). I help my friend when he tunes amps and systems, and we always follow the same evaluation procedure.
I am convinced that it is quite difficult to triangulate a dac performance from other people's comments, as it is influenced by listeners' tastes and, mainly, by dac's synergy with the existing system: in other words, what works for me in my (somewhat unforgiving but greatly musical) system may not work for anyone else.
Both mine and my friends' D70S were tested side by side the following dacs (I was present at all tests):
- Bladelius Embla (my friend's reference, although he added the D70S downstream via AES EBU bypassing the internal Embla dac)
- Soncoz SGD1 (owned)
- Schiit Yggdrasil A1 Unison (borrowed)
- Denafrips Pontus I, original DSP card (borrowed)
- Musician Pegasus (owned)
- Topping D90 (borrowed)
Compared to the D90, the D70s is more extended and "present" in the bass region (tested with piano octaves); going upwards the D90 tends to show some "stridency" in the upper midrange / treble areas. The D70S results more "musical" and "harmonic" than the D90, with a stereo image more extended on the three axis, while the D90 sounds more two-dimensional. On resolving power, both are in the same ballpark, but the D90 brings a hint of listening fatigue with some materials due to its upper registers performance.
As an additional anecdote, both the two friends/clients attending the test, each owning a D90, bought the D70S after the test.
In case of interest for the other comparisons, here some quick notes:
vs Bladelius Embla (a 13.000 Euros beast): I personally prefer the majestic musicality of the Embla, but it resolves less details than the D70S (my "tube friend" actually bypassed the Embla's dac permanently);
vs Soncoz SGD1: no contest with the D70S, as the SGD1 is anemic in the bass region, shows excessive "grit" in the voice region, particularly with male voices, and has an inferior resolving power (choirs are "muddled", whereas the D70S pinpoints every head);
vs Yggdrasil: the Schiit is comparable to the D70S in the bass region, shows better midrange and voices realism, but has a very intrusive and annoying upper midrange - treble sort of enhancement (think about a constant tizz - tizz - tizz in rock tracks). Outside that intrusive treble, I would consider the Yggdrasil overall better than the D70S, but the upper register invasivity was the deal breaker. Looking forward to audition the newly released "Less is more";
vs Pontus I: another "no contest", the Denafrips sounding "bunched in the middle", with undefined bass and a "disembodied" and "cavernous" performance with female voices (more on that with the Pegasus). An easy win for the D70S, although I have the itch to buy the Pontus II after my brief ownership of the Pegasus;
vs Musician Pegasus: the Pegasus started badly, needing 300 hours of burn in before ironing out. But its fundamentals did not change: compared to the D70S, Pegasus' transients are "slower", resulting in less perceived details and a bass region which has body but lacks contours. In a few words, the Pegasus "paints" whereas the D70S "sculpts”, so to speak. The Pegasus is very good with some male voices but, like the Pontus I, gives some female voices (Patricia Barber) a "recessed" character. Some female voices (Laura Fygi) are hair-raising, though. Pegasus upper midrange and treble are softer than in the D70S, more pleasant in a way. In the end, the D70S is more "engaging" with 90% of music. Since I hate switching dacs according to what I listen, the Pegasus went away. Those considerations made me think about the Pontus II.
I understand the initial inquiry was about D70S vs D90, and I added more - probably too much.
Personally, I consider the D70S one of the best "affordable" d/s dacs available. Its Achilles heel can be a sometimes "pointy" upeer register tones - which can also be dependant on materials played, tweeter or anything in between.
Happy to explain and discuss further.
M