This is the review and measurements of the secretive Topping D50 DAC. Other than a small picture and mention on topping's web site, there is no other information on it. I am in fortunate situation that Topping was kind enough to send me a D50 to review and keep. It was a bonus after I asked to buy the Topping DX7s. Pricing is supposed to be $249. According to Topping, it will NOT replace the D30 which makes sense as the D30 retails for half the price.The front panel sports one of the nicest (OLED?) small displays I have seen:I like the confirmation of bit depth in addition to sample rate when playing content.Note that this is a pure DAC. While it has volume control using a joystick to the right of the display, that only controls the RCA output. There is no headphone amplification feature in there.Sadly my Topping DX7 remote did not work with it so to change the volume you have to be sitting close to the unit.As you barely see, this DAC supports PCM sample rate up to 768 kHz and DSD up to DSD 512 so from format support point of view, it is excellent.Connectivity is typical of smaller DACs where there is simply no room for balanced connections:For S/PDIF use which is how I tested mine, you need to supply your own power supply which I did using my lab linear supply.I should say that the unit despite being very small, is very hefty. It is probably the heaviest small DAC I have teste. This is nice to have as otherwise the cables drag on these units.I am sure you all are interested in how it measures. So let's get into that. As usual, if you are not familiar with what these graphs are, refer to my tutorial on understanding audio measurements: https://www.audiosciencereview.com/forum/index.php?threads/understanding-audio-measurements.2351/ Once again: please note that I was given this unit for free. So read as much or as little bias as you like for this review.Let's start with frequency response and channel matching:This is a highly zoomed display so that you can see small changes in response and any channel imbalance. Measured channel level imbalance was at 0.06 dB as indicated.Next let's look at jitter and noise:Here I am comparing it to its more expensive brothers, the Topping DX7 and DX7s. All three push my measurement gear to the limit. But perhaps the Topping D50 is a bit better in getting rid of those two spikes around 18 kHz. But really, these are as good as it gets given the instrumentations I have (and well better than your hearing!).Let's see the favorite of everyone, linearity test:My jaw dropped when I saw the Topping D50 measurement on the left. This is as perfect as I can measure it. At no time does the variation get to 0.1 dB which is my cut off point. Since I am measuring to -120 dB that translate to better than 20 bits of resolution (120/6 = 20). It betters the Topping DX7s which itself was superb in this regard.The Topping D50 sets the record for how clean it is of any DAC I have tested this way!Folks who complain about my 0.1 dB deviation being too strict, should not see why I picked that number. Using a larger value would make it harder to distinguish this superb performance from lesser DACs.Let's look a sine wave at -90 dB which is the time domain version of this test (more or less):Despite the tiny amplitude of this source signal, we see a very good sine wave out of Topping D50. In contrast the Topping DX7s looks a bit rougher even though by itself it is better than vast majority of DACs I have tested.Next let's look at THD+N distortion and noise measurement:Once again we see that the Topping D50 shows better performance especially in mid to high frequencies (in red).Let's see how it does in intermodulation distortion using SMPTE test signals:Ah. We see the same issue as the Topping DX7s with increased distortion from -40 to -20 level. I continue to suspect that this is due to distortion mitigation feature of this ESS DAC. Hopefully Topping gives us a way to turn that on and off so that we can see if that is the cause or not.Finally let's look at the response when fed a 1 kHz full amplitude signal:Here we see that the Topping D50 matches or possibly beats the Topping DX7s. Compared to the now discontinued DX7, the Topping DX7s has lower noise floor and distortions (by a bit).: Tests performed using my new Audio Precision analyzer:Topping hints at the design criteria for the D50 as a better DAC to use with the Topping DX7s. Based on measurements I have performed, it seems to eke out a bit more fidelity, setting a new record in such measures as linearity.If you do not need headphone functionality, and are willing to spend $249, you have my strong recommendation for Topping D50. It provides superb measured performance with great quality feel.Now you just have to wait until Topping offers it for sale.As always, questions, comments, corrections, jokes, etc. are all welcome!----If you like this review, please consider donating funds for these types of hardware purchase using Patreon ( https://www.patreon.com/audiosciencereview ), or upgrading your membership here though Paypal ( https://audiosciencereview.com/foru...eview-and-measurements.2164/page-3#post-59054 ).