Measurements of a $5 DAC

[Robciak]

Hi,

this is a review of digital to analog converter which I bought on a local (Polish) e-commerce platform. Since it is a no-name company, I called it $5 DAC which also indicates its price.
You can easily find similar DACs on Amazon or Aliexpress but the price can vary from $5 to $20. The device is dedicated mostly as a DAC for TV, which which can be powered directly from a TV's USB port.

DAC included power supply cable (without bridge) and optical cable.

Please note:
- I used a old iPhone model charger and the included cable to power the DAC. The performance observed when powering the DAC via USB was lower, and was not included in the measurements below,
- The input level was 0 dBFS. If a different amplitude is used, this will be specified in the measurement description,
- There are no differences between optical and coaxial input so all the following results refer to optical input,
- The following review doesn'tt contain a measurement of built-in headphone amplifier.

Any comments on my measurement procedure or presentation of results are welcome.

This is how 5$ DAC looks like:

Measurements were conducted on Audio Precision APx525 audio analyzer with the following settings:

MEASUREMENTS

RMS Level
Output Level is way under the 2 Volts standard.
Here is a result for 1kHz and in the range 20-20k Hz.

Frequency response
This is what happens when you buy the cheapest DAC because all looks the same. It has an incredibly poor frequency response that drops off after 1 kHz.

FFT spectrum and Jitter
For a 1 kHz input, the FFT shows THD distortion reaching -65 dB for the third harmonic. We can observe all harmonics and each of them takes a high value.

Multitone shows lots of mess even in the low and medium range.

Without surprises, Jitter also showed distortion.

Dynamic Range
Results correspond to around 17 bits for both channels.

THD+N
Total harmonic distortion and noise are very high. The result below gives barely 10 bits dynamic.

Here is a plot describing the THD+N ratio versus the measured level. It is worth noting that increasing levels also increase distortion. Distortion also highly depends on frequency. The below plot shows results for 250, 1k, 6k and 16k Hz. The X-axis also indicates how the measured level differs at different frequencies.

Here is a THD+N in the frequency domain for a 0 dBFS input signal. Unusual behaviour of a curve that rises and then falls sharply.

Intermodulation distortion
Intermodulation distortion has a high value across the band further increasing with frequency.

Summary
As you can see the $5 DAC offers very poor quality and can't be recommended as a TV upgrade.

I am aware that this is a $5 DAC, however the same converter, you can buy on other auctions even for a dozen dollars. At such a price you can find other converters with satisfactory performance.

 

[Salt]

Very welcome report.
You cetainly don't use AP only for checking garbage DAC .....

 

[Berwhale]

Looks similar to the DAC that Amir already measured (with similar results)... https://www.audiosciencereview.com/forum/index.php?threads/worlds-cheapest-dac-review.16594/

*edit* Actually, it's not identical, some of the connectors are in different places.

 

[bachatero]

Where is the panther that got stuck in a blender?

 

[Brian Hall]

Pictures of the interior?

 

[Bleib]

And this is why I don't say all DACs sound the same

 

[Brian Hall]

And this is why I don't say all DACs sound the same

Good ones will.

 

[Bleib]

Good ones will.

For younger ears the wrong filter might ruin the performance a bit

 

[KSTR]

That's one of those "BOM error" DACs (I've seen quite a few so far, in different from factors) where someone selected completely wrong low-pass filter capacitors. Non-existing design review and non-existing production quality control.

 

[Rednaxela]

And this is why I don't say all DACs sound the same

Nobody does.

 

[JSmith]

Pictures of the interior?

... well that was surprising. Seems very buggy...


JSmith

 

[Bleib]

Nobody does.

Not an uncommon claim, I've even read it here @ ASR

 

[antcollinet]

And this is why I don't say all DACs sound the same

No-one else here says this either. Sometimes you might see people say it without the qualifiers (well measuring or measuring transparent etc) but that is only because it is time consuming to add the qualifiers to every statement. Push them on it and they'll clarify - or if they don't someone else will correct them.

 

[Rednaxela]

Not an uncommon claim, I've even read it here @ ASR

All right. Not gonna ask for proof. It only takes one example and I believe you when you say you once came across one.

All DACs is really a lot of DACs though. Most sound the same statements I see here are about transparent DACs not necessarily all DACs.

 

[amirm]

Nice job. Promoted to home page.

 

[Mnyb]

This fr is clearly audible maybe not to some of these reviewers >80 years old .

I vote for BOM error the mfg has no QC wrong component somewhere.

If not in the design someone just put the wrong value in the machine that places them on the boards hence why QC is important.

 

[johnnyx]

It would be fine to drive a pair of analogue VU meters, to give an indication of the level of a digital signal.

 

[DSJR]

Mine dates from 2012 and cost a fiver (UK money) back then. They have changed internally since although the case is similar. Mine just sounded a little 'dirty' at the very back of a mix, but no loss of top - this in the days when I trusted my ears more. Output was also very low but was judged great for older amps with high input sensitivity.

 

[Rja4000]

Thanks for this review.
Interesting.

The below plot shows results for 250, 1k, 6k and 16k Hz. The X-axis also indicates how the measured level differs at different frequencies.

Here is a THD+N in the frequency domain for a 0 dBFS input signal. Unusual behaviour of a curve that rises and then falls sharply.

About the 2 plots above:
It gives a false idea of distortion behaviour at high frequencies, since distortion is limited by the AP bandwidth you selected (unless you changed it for those measurements ?)

At 16kHz, for 22.4kHz BW, no harmonic can be measured, so that's just noise.
And above 7kHz, you don't see the 3rd harmonic either.

You should use a higher bandwidth for the AP to see actual distortion behaviour.
Amir uses 90kHz BW.

 

[CedarX]

Here is a THD+N in the frequency domain for a 0 dBFS input signal. Unusual behaviour of a curve that rises and then falls sharply.

Is this related to the Freq. response of the DAC? What could explain the fall at 7kHz? (EDIT: answered by @Rja4000 above)