This is a review and measurement of Speaka USB "thumb drive" DAC and comparison to AudioQuest Dragonfly Black. It is on kind loan from member Reinhold.The Speak USB DAC is only available in Europe for a measly sum of just 10 Euros. So it would seem to be an unfair fight to compare it to AudioQuest Dragonfly Black which retails for $100 or 81 Euros although this includes Amazon Prime shipping. Either way the Dragonfly is a much more expensive DAC. So why the comparison? Because there is a rumor that the two are based on the same design.The Speaka USB comes in a nondescript gray aluminum (?) packaging of a thumb drive with a cap. There are two LED lights on top and that is it.Power consumption is 70 milliamps. The Dragonfly black on the other hand draws 50 milliamps. This indicates to me that the designs are different.Output impedance is very low at 0.7 ohm. This is at reduced volume to avoid clipping. At that threshold the Speaks delivers 1.32 volts into a 33 ohm load while the Dragonfly only musters 1.18 volt.Let's get into more detailed measurements to see how the two compare. 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/ Let's start with frequency response:We see very good channel balance (output levels) with tiniest bit of droop by 20 kHz.Next let's look at jitter and noise, comparing it to Dragonfly Black:Both have some spikes here and there so a step below good desktop products. Noise floors seem the same but the Speaka has higher output so enjoys a better signal to noise ratio (by about 5 dB). So the winner here is Speaka.Next is everyone's favorite test, USB linearity. This test remains preliminary until I refine it more but I think the overall picture is pretty clear:The Speaka does very well and keeping its output close to idea (flat line). Using my 0.1 dB criteria, it stops at 15 bits of resolution but going beyond nothing bad happens with max error remaining pretty small.The Audioquest Dragonfly Black though, starts to deviate early and drops like a rock after -96 dB. This tells me that this is really a 16 bit DAC implementation and a lousy one at that. Deviation starts to get large at -75 dB which translates to just 12.5 bits of resolution.Speaka is easily the winner here.I was asked to also compare the Speaka to Topping D30. Here is that measurement performed side by side:The Topping D30 is again the next class up with almost perfect reproduction until we get to 18 bits. After that its deviation is small. Speaka holds its own but you do get more when you buy the Topping D30.Digging into linearity in time domain using -90 dB sine wave we get this:We see the issue with Dragonfly Black right away. The output is diminished in level which is the deviation we saw in Linearity graphs earlier. As such it is also swamped with more noise.Here is the Topping D30 (from a previous measurement):It is clearly less noisy which again, is reflected in more accurate response in linearity measurements earlier.After level matching in Roon, there was no audible difference between Speaka and AudioQuest Dragonfly Black in quick AB listening.Unleashing the full output of the Speaka though, put it way ahead of AudioQuest Black. Using my HifiMan HE400i, I had plenty of response and authoritative performance with the Speaka DAC whereas the AudioQuest Dragonfly Black was anemic. I had about 10% reserve on Speaka but none on Dragonfly Black.Results were similar with Sennheiser HD650 which are the least efficient headphones I have.The Speaka USB DAC is the audio bargain of the century. It is a competently designed thumb-drive sized DAC with no obvious flaws. It has just enough drive to produce good listening even with less efficient headphones. It easily blows away the Dragonfly Black and earns myIt falls short of higher priced desktop DACs like Topping D30 which play more formats, more inputs and better measurements. On the latter though the difference is quite small.Much thanks to member @Reinhold for bringing this unit to my attention and allowing us to discover another great jewel. Wish they were available in US and elsewhere outside of Germany. Maybe a group buy can be organized to buy them for interested members.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 ).