Digital Processor Reviews

The Topping DM7 DAC ($599.99) is a high-resolution, eight-channel DAC that supports PCM and DSD sources but will not handle any of the common Dolby/DTS codecs. It employs the highly capable and respected ES-9038PRO DAC chip, ESS's flagship. It has just one input, and it's USB. Its eight analog outputs are fully balanced, but they are TRS (tip-ring-sleeve) phone jacks, which are more widely used in pro audio; most audiophiles will require adapters. Finally, it includes a master volume control and individual channel gain controls (all with 0.5dB resolution), but the finicky up/down buttons on the front panel dictate the use of the included remote for volume control. All these are minor, and they can fade in significance based on the DM7's performance.

This is the second Topping audio device I have reviewed in Stereophile. The first—the Pre90 analog stereo preamp—and this eight-channel DAC share many features, many good and some less good. Both occupy the same clean, trim enclosure and sport the same crisply legible display. Both, on paper, claim great technical performance and features, and certainly the Pre90 lived up to the claims, performing well in my system and on the test bench. On the other hand, in certain areas, both are more limited than their competition, and they may be more limited in warranty support (footnote 1). Then again, both are cheap.

Thoughts while unpacking
Since the Topping DM7 has the same physical dimensions as the Pre90, it is no surprise that it comes in the same packaging. The packing materials are inexpensive, but they're elegantly employed. An AC cord, USB cable, and remote control are included. The front panel resembles that of the Pre90, with a square On/Off/ Multifunction button on the left and a legible OLED display dominating the center. During normal use, the DM7's display shows the volume level in large font on the right with the format (PCM or DSD) and bit rate on the left, smaller. To the right of the OLED are two more square buttons (space occupied on the Pre90 by its volume knob) for volume up/down and menu operations. Across the bottom of the back panel is a horizontal line of TRS jacks for output, numbered 1–8, and a single USB-B input port. Above the USB are two 1/8" 12V trigger jacks, input and output. To the right of all these is a power switch and an IEC receptacle.

The analog outputs of the DM7 present several issues. First, phone jacks are uncommon in home audio. This disadvantage was presumably offset by the compactness of TRS connectors; eight XLR jacks would not fit this standard Topping enclosure. One alternative would be mini-XLR connectors, but I'm glad they didn't make that choice: I have found mini-XLRs to be unreliable. Another option, though—my preference—would have been a single DB25 connector, which could be securely screw-locked. In its common configuration, it would connect cables with eight XLR, TRS, or even RCA.

Second, Topping does not specify channel identity on the back panel, in the menus, or in the user manual. In practice, in JRiver and Roon, channels were output in the proper order for all formats up to 7.1: FrontL / FrontR / Center / LFE / SurrL / SurrR / RearL / RearR. Those planning to use the DM7 for multi-amped, active-crossover stereo systems can arrange the channels to suit. Notably, the latest firmware permits level adjustments for individual channels from the remote control.

Finally, some have taken issue with the DM7's lack of unbalanced RCA outputs. Certainly, there is enough space on the back panel for eight RCA jacks, but there is probably not enough space on the balance sheet to provide both balanced and unbalanced outputs. The obvious solution is to use passive XLR-to-RCA cable adapters, but most ground one side of the differential output; Topping advises against that because it results in the loss of 6dB of output voltage and, presumably, a similar reduction in S/N ratio. The best solution is to keep it balanced. If your preamp has only RCA inputs, just use a proper adapter based on a balun or active stage. There may be some reduction in performance, but you may not be able to hear the difference.

Quick setup
Installation of the DM7 was quick and easy. Since my server is PC-based, I needed to download and install Topping's ASIO driver for the DM7; Mac users can skip that step. After I connected a USB cable, Roon and JRiver recognized the device, and I was able to configure the DM7 as an output device.

At the eight outputs of the DM7, I inserted short TRS-to-XLR cables (footnote 2) and plugged those into my eight-channel switch along with the other sources in my system. I could connect them directly to my stack of Pre90 preamps, or I could bypass switches and preamps and plug them directly into my power amps, using the DM7 to control volume. That's probably what most users will do. That's it; setup complete.

The DM7's menu has several interesting options including the ability to choose among seven PCM filters and four DSD filters. I used the Fast Roll-off, Minimum Phase PCM filter and the 70kHz DSD filter, both of which I use on my other DACs. The DM7 also has PRE and DAC modes, which permits or disables volume adjustment; I left it in PRE mode but, for comparison with other DACs, set it to 0dB. According to Topping, this is equivalent to DAC mode, and I found it indistinguishable from it. There are two maximum output levels: 4V, the default, and 5V, each voltage RMS corresponding to full-scale input. I left it at default. The menu also has settings for display time out, triggering, and brightness.

And then there is the matter of volume control. As I noted before, the DM7 has two small up/down buttons. These are okay for menu operations, but they are not suitable for volume control; using the buttons to adjust volume was tedious and slow. Even fine-tuning volume was annoying, as it required switching between buttons. Fortunately, the DM7's remote control, though also based on Up/Down buttons, is more convenient, comfortable, and controllable. It allowed me to avoid frustration and, I am happy to add, its operation was noticeably more reliable than the one on the Topping Pre90. Volume control from within Roon, JRiver, or other music sources is also an option.

The payoff
After I selected the DM7 as the output device in Roon and JRiver, I wanted to hear something new. The timing was just right. For many years, I have really enjoyed Holst's St. Paul's Suite whenever I have come upon it, especially, the third movement Intermezzo. Written to mark the opening of a soundproof music studio in St. Paul's School for Girls in Hammersmith, it is filled delightfully with variants and interlacings of traditional melodies familiar from Holst's other works, such as the Second Suite for Band. The quasi-Oriental section that opens the Intermezzo, with its solo-violin melisma, is perfectly placed and startling. I already had two recordings of the suite, but neither was especially satisfying, so I looked for a better version, in multichannel if possible. HRAudio. net listed three. In my auditions on Qobuz, one stood out, the one by Ensemble Esperanza. I ordered the SACD (Ars Produktion ARS 38 227, SACD), which arrived in time to be ripped and played back for the DM7's debut in my system.

The clarity and spaciousness of the recording was wonderful, the dynamic range impressive, in stereo or multichannel. Both versions approached, but did not equal, similar achievements (in different music) of the much immersive 2L recordings by the Trondheimsolistene; still, the DM7 rendered a traditional and believable soundstage from the Ensemble Esperanza's recording. I heard striking purity in Chouchane Siranossian's solo violin, especially in that wonderful Intermezzo—and also in the suites by Grieg, Bridge, and Nielsen that fill out the disc.

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Footnote 1: It seems to me that Topping has emphasized making a high-quality product at the lowest possible cost, with the expectation that there will be little need for extended warranty support. The basic warranty is only one year, and internet purchases may require shipping to China for warranty repairs or replacement. While none of my Topping devices have failed, buyers need to assess their personal tolerance for dealing with the possibility.

Footnote 2: I used Monoprice TRS-to-XLR cables, but there are many alternatives from other sources of your choice.