Today, let's start with what I'm aiming to be a 3-part review/discussion of the Topping D90SE DAC. I figure I'll take my time on this since things are busy around here and I hope not to purchase more hi-fi DACs going forward, so I might as well savor the moment. ;-) As a "more objective" audiophile who has a vision of aiming for "high fidelity" / "transparency", there is a clear target and end-point to what's needed from hardware performance especially with DACs.
Readers of this blog know that I've had a number of Topping devices reviewed here over the years. In fact, for any single brand of DACs, I think I've reviewed more Topping gear here than other brands. This, I believe, is a reflection of a brand that provides multiple products at price points with features that actually speak to me as a consumer interested in value which includes features, and price. I have certainly not been disappointed by overall quality to this point.
At a current retail price of around US$900, this is not an inexpensive model. As per most of my reviews, I bought this through usual retail channels so what I'm reporting on here is not any potentially specially-selected unit sent from the manufacturer.
Feature-wise, this is a DAC only but accepts multiple inputs - USB, HDMI-style I2S, S/PDIF Coax, S/PDIF TosLink, and wireless Bluetooth 5.0 (SBC, AAC, aptX [LL,HD], LDAC). While it has both unbalanced RCA and balanced XLR outputs, there is no headphone amp. For that, Topping recommends grabbing their top model the Topping A90 (~US$500).
What makes this DAC interesting in mid/late 2021 is that this is reputed to be the highest fidelity converter in the world (available to consumers) at this point in history, Topping's "flagship" device.
Let's take a look...
A. The physical unit & the DAC technology
|Note: Item 11 - Polarity setting is around these other options because it only refers to IIS output polarity as relayed to me by a friend. Apparently this doesn't do anything for the other PCM/DSD inputs.
I guess you'll just have to look at your source device pin-outs to check polarities and which pin is used for DSD signaling. Here's an interesting resource if you want to look up various HDMI pin assignments.
The remote controller is the standard plastic "Topping RC-15A" which is identical to ones supplied with some of their other DACs. For example, the Topping DX3 Pro uses this controller as well. The central round button selects whether RCA / XLR or both outputs active. Left and right selects which digital input. +/- for volume.
Of the lower round buttons, the "FIR" button selects one of 7 digital reconstruction filter options. The "AUTO" button puts the DAC in "auto standby" mode which will put it to sleep after 1 minute of not seeing connection on the selected input and wakes up when it does. The bottom right button is for brightness and there is a selection of Lo/Med/Hi brightness with an "A" setting that is of medium brightness then automatically goes blank if no display changes in 30 seconds, waking again when changes like volume adjustments are made.
At this price point, I would have certainly liked to see a more robust remote controller (metal), preferably customized for this DAC without unmapped buttons (like that headphone button).
Before going into measurements, I think this is a good time to talk about what makes this DAC special in terms of high fidelity performance. At its heart, the D90SE is built on the ESS Tech ES9038Pro DAC chip which actually has been out since 2016 with a potential for mono, 2-channel, and 8-channel conversion output modes. Back in 2017, we considered the Oppo Sonica DAC, and in 2018 looked at the Oppo UDP-205 - both also based on this chip.
Beyond just channels, the ES9038Pro can also function in either current or voltage modes with the current-mode preferred for lowest distortion. And in order to get the cleanest, most linear performance when transforming the current into analogue voltage output, high-quality current-voltage converters (I/VC) have to be implemented. As you can see in the Topping D90SE literature, they've incorporated independent 8-channel I/V conversions. No cutting corners with voltage mode operation, 2-channel mode, or even combining channels before the I/V stage in the D90SE design:
|The Topping D90SE 8-channel I/V conversion using TI OPA1612A "SoundPlus" opamps.
Let's start looking at the measured performance...
B. Measurements: Oscilloscope, digital filters, and MQA
|Display during playback. Note the input --> output settings, sampling rate, type of data (usually "DSD" or "PCM", "OFS" here for MQA), and dB attenuation.
|Note: This was captured with the RME ADI-2 Pro FS hence the rising ultrasonic noise to 192kHz (24/384 sampling).
C. Measurements: Jitter
Conclusions from Part I
- A suggestion for Topping if they update the firmware - I would love to see a "FIR Filter Lock" in the set-up menu that prevents easy switching of PCM/DSD filters with the "FIR" remote control button. In use, I think most listeners select a filter option and stick with it. No need to fool around with this and I don't like accidentally pressing the button and having the filter switch so easily without notice.