Setup and Performance

Setup

If you decide to have the TOPPING A70 Pro amplifier paired with the D70 Pro SABRE DAC as a stack, you have the option of going with balanced dual 3-pin XLR interconnects or single-ended dual RCA interconnects. Knowing that the A70 Pro's big selling point is the amount of power it can put out, I suspect most people will go with the balanced connections thinking that is the only way to get the most power. But really this is where a lot of people get confused between balanced headphone outputs and a balanced connection feeding the amp. If you only care about the power output of the A70 Pro, you can feed it either a single-ended or balanced connection from the DAC. The latter only really helps further reduce channel crosstalk and input sensitivity but really the A70 Pro is designed to have even cleaner sound off the RCA inputs! In practice go with whatever you want, I just went with these XLR interconnects because I had recently used them and they were easily accessible. I also prefer having the amplifier above the DAC so the headphone outputs are closer to reach; there isn't a big deal thermally having one over the other here. Then you need to consider about the other cables required to where, for me anyway, I had the two power cables and the USB cable on the DAC in addition to plugging in the Bluetooth Antenna for when I wanted to use my phone as the source connected to the DAC. The stack is quite solid with all these cables owing to the size and the aluminium alloy chassis used so you do not need to worry about this budging or tilting in either direction in use.


The shared design language as well as the common dimensions of the chassis on both units make for a well-matched stack. Turn both on using the switches on the back and you will hear a soft click before the display turns on to show the TOPPING logo fleetingly before asking you to select the operating language—this can be changed later too. Of course I went with English and now the default home pages on both displays were up wherein you see both set to -30 dB (on a scale of 0 to -100 dB) in addition to other indicators showing the current state of the inputs and outputs as well as the gain setting. A subtle L/R channel level indicator is also present on both displays which is more obvious when something is playing. To make the best use of the display, TOPPING has incorporated what it calls "Aurora UI" and this is where the bottom button to the right comes in too. You can choose between one of three home page screens with the other two being a fancy VU meter—I especially liked this on the amplifier where you can quickly see the output voltage, and hence also how loud it will be, and make sure you aren't in for a nasty surprise when you plug something into the headphones or place them over/inside your ears. The third option is an FFT which I was using on the DAC when I wanted to see what frequencies some songs were playing more over others, but soon I went back to the default playback info screen on the DAC. It's still nice to have these options and I expect to see TOPPING continue to use these displays on future products if the recently announced DX9 is anything to go by. The displays are crisp and have enough clarity/resolution to where you can't really make out the individual pixels, and color reproduction is more than decent for an LCD panel. Oh, and you can set both units to standby mode by using the remotes or holding down the knob buttons.


The remote you get with the D70 Pro SABRE is quite useful in that you can easily do every single thing from a distance, including volume control and input/output channel switching, You can still do all this without the remote using the capacitive buttons and the knob though, including accessing the setup menu. There are several customization options here, including for the display where you can select the home page as seen before, the screen brightness level—auto turns off the display after 30 seconds of inactivity, the reference voltage for the VU meter, and whether or not to display the level meter on the various home pages. The input selection is obvious enough as is the output mode where you can choose to have either or both outputs running, and there's also control over the 12 V trigger. TOPPING provides a choice of seven PCM filters although you need to refer to the manual to know what they are. F-1 (minimum phase) is set by default and that's how I left it since the other filters are more likely to cause treble roll-off than anything else. The advanced settings are neat in offering some things I haven't seen before on TOPPING DACs, including an adjustable sound mode—off, valve, or transistor—which seemingly affects the overall timbre. It's subtle though, and I found it funny that TOPPING is deliberately trying to add some color to its otherwise transparent sound. You can also change the max output level from 4 to 5 V for XLR and 2 to 2.5 V for RCA which apparently people requested, I am not sure why given the platform is super powerful and compatible as it is. You can account for any channel imbalance here too as well as turn on/off Bluetooth and remote control, choose between using the DAC as a preamp or not, provide a custom function to the knob button, and fiddle around with the bandwidth setting in case you somehow notice jitter without an actual audio analyzer.


The setup menu for the TOPPING A70 Pro amplifier will feel familiar now since most of the settings are similar, if not identical. The same Aurora UI used on both units for the display plays a role here. There are amp-specific controls over the gain level—just low and high, more levels would have been nice on this beast—in addition to choosing the output mode and associated headphone output or preamp out be individual or all (both on). The advanced settings allow you to set a safe volume mode which many other reviewers seem to have missed. This helps address a potential issue where an accidental turn of the volume knob can send a lot of power to your headphones and ears by forcing the output to a default volume after 10 seconds if you go over it and do not deliberately set to that level. For example, the unit comes set to -30 dB by default for this reason and you can choose to have a safe volume anywhere or 0 to -80 dB once you have configured the amp and headphones together. This is all the more relevant if you have multiple inputs and outputs in the stack and also have different devices running off the amp at the same time.


Excuse the shaky camera work, I had to zoom in on my phone to take a video each to show the VU meter and FFT screen in action. Let's just say it's far steadier in person but you get the idea of how these work now.


I did try Bluetooth input on the D70 Pro SABRE DAC to see how well it worked, with the DAC automatically going to pairing mode and recognized by my phone. It offers Bluetooth 5.1 connectivity with a rich codec support including SBC, AAC, aptX, aptX HD, aptX Adaptive, and LDAC, with my phone in LDAC mode doing a good job offering that flexibility of having the stack on my office desk when I cared less about the best possible sound quality and more about convenience. There's also coax and optical inputs offered here with up to 24-bit, 192 kHz PCM and DSD64 playback for use with TV tuners, turntables, CD players etc.


The bulk majority of my testing was done with USB input to the DAC and here the display will confirm that the D70 Pro SABRE defaults to 32-bit, 48 kHz PCM playback in Windows. Indeed, the sound controls in Windows confirm as much and you can get 16/24/32-bit PCM playback up to 384 kHz directly without needing any drivers. Your preferred media player should also see it and allow PCM/DSD playback. Roon also sees the device but doesn't identify it, so you have to enable it and set it up in the audio settings tab there.


If you have a device that doesn't accept UAC 2.0, or simply want to try other options, then the TOPPING-skinned XMOS/Thesycon USB audio device drivers will be of interest to you. You can find the installer on the downloads page and the latest version at the time of testing was v5.62.0 from a couple of months ago. Installation is trivial as seen above, and these drivers now allow you to make the most of the TOPPING stack within the Windows operating system.



What these drivers do after installation is create a new output device in Windows, also providing access to the TOPPING USB DAC Driver Control Panel. You would mostly use these drivers in newer Windows builds if you want to have the stack as an ASIO (Audio Stream Input/Output) device. Set the format to your choosing and choose the buffer size based on latency requirements. With that done, go to your media player of choice. I demonstrated above with JRiver and Roon again and set the audio player to the same output. At this point, you can implement further tweaks, but those are player dependent. These drivers also provide 16-bit playback support as seen above, and Roon automatically allows for native DSD playback upto DSD512.

Audio Performance

The TOPPING D70 Pro SABRE DAC is the best ESS DAC implementation I have heard to date, with maybe FiiO taking the second spot on some of its ES9038PRO-based DACs and DAPs. Gone is the dreaded sterile sound and the hint of brightness some perceive with ESS DACs, especially compared to the likes of AKM and Burr-Brown DACs which tend to present a more neutral/mid-forward sound to the ears. We are splitting hairs here though and ultimately the difference between these more mainstream delta-sigma DACs is about the same as what you would get from simply changing the sound modes on this DAC. Suffice to say that it's overall clean, transparent, and never going to hold back any amplifier you are connecting down the chain. It's the A70 Pro amplifier that is more interesting in a few different ways. First up, we need to talk more about that high power output I've been briefly mentioning over the course of this review. Would you believe that this thing can put out at least 17 W per channel at a 16 Ω impedance while still keeping distortion ultra low? This is more power than really 99.9% of people reading this review need and I have to say right away that the best use case for the amp is with harder-to-drive headphones and IEMs. There's a reason TOPPING shows off the A70 Pro with the HIFIMAN Susvara connected in the promo photo, and other such use cases would be the Modhouse Tungsten, the Ploopy Headphones, and perhaps even the likes of the DCA STEALTH and the HEDDphone ONE/TWO. Think low sensitivity transducers thus, especially planar sets when it comes to over-ear headphones. There are a very small number of IEMs which are harder to drive than you would think with the Symphonium Helios/Helios SE, Subtonic Storm, Symphonium Crimson, and the upcoming Nightjar Duality coming to mind which can benefit from having the vast amount of headroom available here.

But really even these harder to drive sets are not going to need the 17 W on offer, except perhaps the Ploopy but that's a whole other story. Even if the actual numbers are slightly under the rated ones, I don't really see the A70 Pro been a must-have simply for this. In fact, even with higher impedance headphones, it can give out a lot of power off the balanced outputs—12.6 W at 32Ω, 6 W at 64Ω, 1370 mW at 300 Ω, and 670 mW at 600 Ω. Go with the single-ended output and things feel more reasonable with "only" 6 W per channel at 16 Ω going down to 165 mW at 600 Ω. This I can see being useful for production rooms where high impedance headphones and a 6.35 mm single-ended headphone output is the norm. But either way please be aware of the safe volume option and also note that the DAC and amp both retain volume memory in various input/output combinations so check twice before playing anything. The good news is the new amplifier architecture ensures a completely black background and doesn't get in the way of you enjoying the sound being played from the headphones/IEMs alike. Note also the frequency response of the stack being pretty much perfect—no complaints here. Don't go expecting to hear magic from the stack when it comes to changing the perceived soundstage or dynamics of the actual sound though—especially from the amplifier. TOPPING advertises clean sound and that's what you get here.