Topping D90

This is quite the DAC, $699 for this package is quite interesting.

If you like neutral and detailed sound, you'll fall in love with this DAC, but there are some drawbacks.

For starters the DAC sounds lifeless, don't expect it to increase soundstage, add warmth, improve musicality etc. This is not an audiophile's DAC. It measures almost perfectly with a SINAD of -120dB and THD of 0.000093% on CH1 and 0.000096% on CH2. Impressive measurements making this DAC so neutral and clean it is perfect for mixing or professional use.

If you like ruler flat neutral this is your DAC, otherwise you may be a bit perplexed.

How do you resolve this?

You can opt for a different DAC, such as a Denafrips Pontus or even the Ares II. Or you could add a tube preamp such as a Freya+ from Schiit Audio. Freya+ with Tung-Sol tubes will add warmth and musicality while slightly increasing soundstage, making it close to the performance of my friend's Yggdrasil G1. Another benefit of the preamp is you can then use solely the XLR out of the DAC giving you the best performance (RCA only uses half the DAC). Then if you need single ended out you would take that from the preamp.

Some have reported worse sound quality when using the preamp function, but I did not notice any difference, and measurement wise it is essentially the same (THD still 0.000096% or better).

The included aluminum remote on some Topping D90 orders is worth the $20 extra, it is much nicer than the cheap plastic remote.

Drivers are extremely smooth on Windows 10 and Mac OS, in comparison my SMSL Sanskrit 10th MKII had horrid drivers on Windows causing freezing on occasion until I updated them from the manufactures site. You will not have any trouble with Topping's drivers that they provide to Microsoft.

Summary: This DAC has the details of a $2000 DAC but lacks the textures and qualities a lot of audiophiles may seek, making this a very perplexing product. Honestly, without the Freya+ I don't think I would've kept this DAC. But I do not regret the pairing between the two, in my opinion this setup is superior to the Yggdrasil G1. Now how it compares to Yiggy G2 remains to be heard .

Thanks for reading,
Tom.

Thanks to Shenzen Audio for sending me the Topping D90 for review.

After I reviewed Schiit Audio's Bifrost, I had quite a few people interested in my reviewing the equally priced Topping D90. Topping has been known for its DACs that measure very well, which appeals strongly to a subset of people who want some form of verified performance measure.

While I'm personally not interested in DACs that use the AKM4491 or 4493, my recent good experience with FiiO's M11 Pro and it's AKM4497 DAC made me more interested in the AKM4499-based Topping D90.

I tend to be somewhat wary of well-measuring DACs. Another well-measuring DAC, the Benchmark DAC 1, was a popular DAC over a decade ago when I started on Head-Fi, yet it wasn't exactly the most musical — it tended to sound rather bright, and "digital". Likewise, some of FiiO's DAPs, while measuring well, up to at least the M11, sound a bit sterile.

The DACs that buck this trend have been from Chord, with their FPGA+transistor designs, though somewhat dependant on how they are set-up with a suitable transport.

So, it was with interest that I agreed to review the Topping D90. Functionality-wise, it's about the size of the Schiit Bifrost, and slightly slimmer. Whereas the Bifrost focusses on upgradability and is PCM-only, the Topping attempts to be a jack of all trades, supporting up to 768k input (via USB) as well as DSD. It also supports a pre-amp output (bypass-able for a possible increase in sound quality).

XLR and RCA outputs can be switched on and off separately for a choice of where music goes, the pre-amp can be bypassed, and the digital filters on the AKM4499 can be changed as well.



I ran the D90 initially straight from my Mac Mini Roon server via USB. With both connected to an Audio-gd Master 9 or ALO Audio Studio Six, I could readily A/B them. I subsequently tried both from a Soundaware D300REF streamer, the D90 connected via I2S (and AES briefly) and the Bifrost via S/PDIF.

I2S, for the unfamiliar, is a connection between internal DAC components. While S/PDIF, AES and Toslink carry both digital data and the clock signal in one connection, internally, a DAC separates out the components, transmitting them over separate lines, in much the same way you have composite and component video, with their one and three connections respectively.

Taking the I2S connection outside the DAC, there is a potential for improved sound quality, though whether it makes for an improvement over AES and S/PDIF is likely DAC-dependent. There are also a number of different connection arrangements, so you have to ensure that your digital transport's I2S is compatible with the With the Topping D90's I2S. To that end, the D90 has a special mode, accessed by holding the front power button down while switching it on at the back. This allows a compatible I2S mode to be selected.



Initial impressions reminded me of the FiiO M11 Pro, which uses the AKM4497. The D90 has a smoothness to the sound which makes for pleasant listening, though, regardless of filter choice, was a bit flat-sounding, and with pre-amp mode on, didn't bring out quite the level of nuance and detail that the Bifrost 2 can. The Bifrost 2 brought out a bit more depth and feeling, such how it reproduced instruments on David Chesky's Jazz in the New Harmonic. The subtleties of both the decay of notes and their echo off the recording venue were more noticeable from the Bifrost.

Turning off pre-amp mode brought things closer to the Bifrost, if not quite up to Yggdrasil level. With more apparent detail and less of the "flatness", the D90 seemed to do its best not to impose itself on the music.

Switching to the D300REF as a source seemed to overcome the D90's limitations, bringing it (in a very expensive manner) up to near Yggdrasil level. Listening through an Audio-gd Master 9 with Van Den Hul The Orchid cables to a pair of Final D8000 Pro, the Yggdrasil still just had an edge on depth and nuance when listening to Jazz in the New Harmonic by David Chesky (192/24) or Mark Ribot y los Cubanos Postizos (16/44.1 TIDAL) with the D90 set to filter 1 (linear phase).

Slightly confusing the issue was a small mid-bass hump in the Yggdrasil, a result of uneven crosstalk caused by the DC offset circuit in the output stage that can make the DAC sound like it has a bit more bass on some tracks.

Compared to my other, usual go-to DAC, the Chord Hugo 2, the Topping/Master 9 or THX AAA 789 combo couldn't compete to the direct headphone output in terms of nuance and detail, though only on the best-quality recordings I have here, such as Decca masters and recent Chesky recordings.



Since I wanted to experiment with up-sampling to the D90, I switched to using a Kitsune tuned Singxer SU-1 USB to S/PIDF and I2S converter. Some quick experimentation with HQPlayer to see what, if anything could be achieved by PCM up-sampling, I had some pleasant results from the SINC filters, which produced a very "floaty" sound and the million-tap closed-form-M which emulates something similar to the punchy and precise filter that Schiit Audio uses. The latter I reckon was about spot-on for most music, balancing up the overt smoothness of the DAC beautifully and making for very pleasant listening.

What was most surprising about the comparison, however, was how close it was possible to make the D90 come to the Yggdrasil for about two-thirds of the cost (or more if you include a HQPlayer licence). For most music I don't believe I would be able to make out the difference in a level-matched comparison.



That left my impression of the Topping D90 of a DAC capable of being quite detailed and smooth in the right system, such as one with a good USB, IIS or coax/AES transport. In others, and especially with the pre-amp circuit engaged, it can end up sound a bit flat and un-involving. All the same, one can't ignore the great value it provides for the $700 asking price.

Impressions from viewers of my video confirmed this, with some reporting (mainly the new MQA version) a positive experience, and others feeling it sounded too flat.

As with all DACs, system synergy has to be considered, but I can still recommend the D90 as a standalone DAC, especially for people who wish to go the extra mile to get it sounding good in their system.

FIRST AK4499 DAC TO MARKET
The Topping D90 was the first commercial DAC using AKM's latest and greatest DAC chip, the AK4499. On paper, this DAC chip boasts a THD+N of -124dB, which is lower and better than AKM's previous flagship, the AK4497 at -116dB. Many people believe that DAC technology has been more or less figured out at this point, and that a $100-200 DAC is good enough for most purposes. Therefore, at $700, the Topping D90 is held to a higher standard and must perform flawlessly for it to be a good buy.

Upon release, certain sites measured the D90 and gave it the highest praise. This is exactly why I bought the Topping D90. I thought it would be the last DAC I would ever need to buy. Unfortunately, the Topping D90 stumbled right out of the gate for me.

BROKEN USB IMPLEMENTATION
The first input I tried was USB. Immediately, there were two issues:

• USB noise interference
• Popping sound a few seconds after audio playback stops

There was a faint, but very audible noise coming from my headphones when no music was playing. To make sure it was the D90 and not my amp or cables, I plugged in several other USB DACs into my amp, as well as trying multiple cables. (None of the cables cost more than $15.) No other DACs exhibited the noise. In addition, after a few seconds of no playback, I heard an audible pop. Apparently, in Windows 7, the driver goes to sleep after a few seconds. This is documented at: https://www.head-fi.org/threads/topping-d90.926531/page-2

This is ridiculous. I have plenty of older DACs that don't exhibit this behavior. It doesn't matter if you set Windows settings to always never have the USB device or port sleep. The driver is ordering the DAC to go to sleep, thus the popping.

Fortunately, my PC tower has optical out. The D90's optical input works perfectly, though you're limited to up to 24-bit/192khz instead of up to 32-bit/768khz. I was happy with using optical input exclusively.

CATASTROPHIC FAILURE
For this review, which came 3 months after purchase, I wanted to see if the issues mentioned above were due to Windows 7's USB audio implementation. So I obtained a Windows 10 test laptop. The issues became worse when I plugged the D90 into the laptop. The audio I heard crackled heavily for 1 minute. And then suddenly, the laptop no longer recognized the D90. I tried plugging it back into my PC tower. Nothing. The D90's USB input had completely died. Fortunately, optical input still worked. Did the USB input break because I had the optical cable plugged in with a music signal at the same time? Who knows, but it still shouldn't have broken like that.

CAN'T DISABLE DISPLAY
One additional point of contention is that the display can't be turned off while the unit is operating. You can change how bright it is, but you can't turn it off completely. This is a major distraction when watching movies in a darkened room. You'll need to cover up the display with some electrical tape. Easy fix, but on a $700 unit, this shouldn't even be an issue.

CONCLUSION
With the D90's USB input giving me issues from the very beginning, then suddenly failing on me when writing this review, I can say with certainty that you are playing a slot machine when buying this device. It does have a 1-year warranty, but the exorbitant shipping cost for warranty service from North America to China has discouraged me from sending it in. At least I can still use the unit's optical input, and it does work well enough there, so I'll give it an extra half star for that.

Not recommended at all.