Topping D70 DAC Review and Measurements - Stream of Consciousness

• Human interface issues: https://www.superbestaudiofriends.o...nts-stream-of-consciousness.9318/#post-301203
• Effect of filters explained: https://www.superbestaudiofriends.o...nts-stream-of-consciousness.9318/#post-301219
• Subjective impressions: https://www.superbestaudiofriends.o...nts-stream-of-consciousness.9318/#post-301395
• Typical measurements: https://www.superbestaudiofriends.o...ream-of-consciousness.9318/page-2#post-301703
• IMD stuff: https://www.superbestaudiofriends.o...ream-of-consciousness.9318/page-3#post-301778
• CONCLUSION: https://www.superbestaudiofriends.o...ream-of-consciousness.9318/page-3#post-302654

I'm jumping ahead of myself, but I am not impressed. It's like turning back the clock back to sigma-delta nasties of 2010 (sssshhh, sssshhh, sssshhh). If you want the ultimate expression of the AKM sound, get the RME ADI2. If you want something very close to that kind of sound for x10 less money and don't need the RME's features, get the Modi 3. Topping couldn't do anything with the AKM4497, two of them, which is AKM's second to TOTL chip. This will be one of those stream of consciousness / ongoing reviews because I would like this to be complete. Perhaps my initial impressions were wrong and I can revisit. Current and prior owners can chime in if I am missing something, and readers can make "requests" as usual.

Topping D70 (x2 AKM4497) with AKM4490 based Modi 3 to the left (both in back)


One particular annoyance is that the DAC by default is set to only work from the RCA outputs. Evidently there is a relay that allows the outputs to be toggled from RCA to XLR to RCA+XLR. The front panel interface seems simple enough, but for several minutes I could only get it to toggle sources (AES, SPDIF, USB, IIS), but not toggle the output to XLR. I found this highly annoying as practically every DAC in existence will have both sets of output active. Obviously, the next step was for me to consult the instruction manual. As I am not a retired one-percenter, I really don't have time for this shit. Grrrr.

Front panel is elegant with SEL, forward, and back buttons.


Anyway, if someone can tell me how to do the output select without using the remote, please tell me. I'm assuming Topping put a relay in there to max out THD+N / SINAD and SNR.

 

The art of the instruction manual is to get the point, or at least offer a table of contents were I can find the pertinent information. Instead, I was reminded of how well the D70 measures on steady-state sine waves or combination thereof.


I would appear that Topping, which a year ago was just a rando manufacturer, now has a marketing shtick, courtesy of the ASR. I'm not sure how these measurements benefit the end-user. Perhaps I can mount these instructions on a picture frame so I can assure myself that I have one of the best measuring DACs in the world, laughing at people who spent $8k on Bricasti or Rockna DACs, knowing that I outwitted them all.

It wasn't too difficult however to find the pertinent section that would tell me how to toggle the output from RCA to XLR.


Ok guys, after reading the manual, can you tell me how to toggle the output from RCA to XLR? Note that we are reminded yet again of the D70s awesome SINAD and SNR! It's like we can escape Topping telling us how much "science" went into the D70.

 

Yeah, it's the middle button on the Amazon Fire TV, I mean Topping D70 remote.

 

WTH? So I held down the SEL button while I plugged the power cable in. I get the settings menu now. Very intuitive.

Next step is to figure out which filter mode is which, via measurements, since the manual doesn't explain anything about this. I don't understand why the each filter's FR and ripple wasn't shown on the manual since the manufacturer already went through the effort of providing a host of other measurement plots.

 

As an aside, I like what iFi did with their filters, offering simple English labels such as "Measure", "Listen", and "Bitperfect". Whether the consumer knows exactly what is going technically on is irrelevant. The point is so that the consumer can related a word to the sound of a filter. Note the below are with 48kHz sampling frequency. The AD conversion is 96kHz, so I didn't want 44.1kHz sampling rate causing any kind of aliasing.

Mode 1 Filter
Let's take a look at the six filter modes. Note that most of my listening so far has been with Mode 1. It turns out this is a linear phase filter with a sharp knee.

Mode 1 Filter Frequency Response


Mode 1 Filter Impulse Response



Mode 2 Filter
Mode 2 appears to be a linear phase filter like Mode 1, but with a slow roll-off. We trade off some high-frequency roll-off for less ripple.

Mode 2 Filter Frequency Response


Mode 2 Filter Impulse Response


So far, everything appears to be in the order of the AKM4497 datasheet, but we should check just to be sure. It's never a good idea to assume.

 

Mode 3
This is the minimum phase filter. The AKM datasheet calls this the short-delay. This is a bit hint that a minimum phase filter is used. The knee is sharp. There is no pre-ringing, but post ringing is worse than linear phase. Once upon a time, some DAC manufacturers heralded this filter as the next step of realism, because "pre-ringing" doesn't happen in real-life. I always felt minimum phase filters sounded like butt and have always preferred linear phase. In my subjective listening, this filter was the most edgy and difficult to listen to, at least for me. Even from stock HD650s, I could not stand the highs.

Mode 3 Filter Frequency Response


Mode 3 Filter Impulse Response



Mode 4
This is the minimum phase filter or maybe a variant, but definitely with a slow rolloff. The ripple is asymmetrical where these is slightly less pre-ringing to post-ringing.

Mode 4 Filter Frequency Response


Mode 4 Filter Impulse Response


If our heads aren't already spinning with the myriad of choices, we have two more to go!

 

Mode 5
This one is interesting. It looks like a tweaked variant of the linear phase with ripple behavior somewhere between Mode 1 and Mode 2, but with FR closer to Mode 2.

Mode 5 Filter Frequency Response


Mode 5 Filter Impulse Response


Mode 5 vs Mode 2 Filter Frequency Response
GRN = Mode 5
YEL = Mode 2

As we can see, everything is a tradeoff. There's no free lunch.

 

Mode 6
Now, this one is super interesting. It looks like a tweaked variant of Mode 4 minimum phase. The knee of the roll-off extended a bit. As a result, get a little bit more ripple in the impulse response.

Mode 6 Filter Frequency Response


Mode 6 Filter Impulse Response


Mode 6 vs Mode 4 Filter Frequency Response
GRN = Mode 6
YEL = Mode 4

 

I may have other competitive DACs coming in - not too sure that this moment. But this is what I have to compare to:

$100 Modi 3: AKM4490
$600 Motu Ultralite: ESS Sabre - some run of the mill with lot of channels, but same specs at AKM4497
$500 Topping D70: x2 AKM4497



In regards to the D70, under a variety of sources from computer USB (from dedicated USB PCI cards with their own 5V from the power supply) to coax (from Pi2AES) and using various amps Magni 3+ to my custom EC x4-45 with various headphones (Borealis, HD650, Verum, HD800, etc.):

• Not as resolving as I had hoped for. Microdetail just a hair behind Modi 3. I didn't quite believe this, but I went back and forth several times to check. Yeah, there's fine detail, ambient cues, etc. which is missing relative to the other DACs.
• Filters do something, the their effects are not major like I've heard on ESS based DACs where it's offered. I eventually settled for Mode 6, after initially starting with Mode 1. Still, among the DACs here, the D70 sounded the grainiest with a bit of that sigma-delta hash (shhh, shh, shhh). The ESS based Motu actually sounded the most fluid. Sharper transients, squarer sound, as expected from Sabre, but not to a nasty extent - think X-Sabre Pro.
• Thus the Motu Ultralite mk4 had the most evident macro-detail.
• Both Modi 3 and D70 had an overarching thickness and mushiness (Velvet Sound trademark). However, Modi 3 was less thin and also less mushy at the same time. What I mean by this is that during passages without much low frequency content, vocals, instruments and so forth had more "body" than the D70. And during passages with bass content, the D70 sounded more mushy.
• Both Modi 3 and D70 exhibited wide-expansive stage. The Motu blew them both out of the way in terms of soundstage depth and instrument localization depth; however imaging was a hair the behind in terms of precise lateral position.
• The Motu isn't as thick in the lows; however it does have a enveloping warmth. A warmth that's not focused on the upper mids or lower mids, but rather throughout the entire frequency band. Think of the sound an smelly old-school console with transformer coupled inputs and outputs.
• Finally, the Motu is simply more engaging than the others. Better "PRaT", more contrasty microdynamics, greater immediacy. How do I know this? I still had the headphones on past 1am last night listening to music. As @insidious meme says: "You can tell that Marv likes something if he's still listening. The longer the better the gear. He'll rip those headphones off quickly if he doesn't like the sound."
• The Motu Ultralite mk4 could just have a different kind of sound that I happen to prefer. Kudos to their engineers for picking the filter that they felt sounded best so I don't have to fart around for hours over two days. If the AKM Velvet Sound is what you want, the logical step up from the Modi 3 is really the RME ADI-2. The Topping D70 isn't horrible but it's a step back from the Schiit Modi 3.

I'll do a spider-web chart when the time comes.