Amazon Basics Optical Coax DAC Review

[amirm]

This is a review and detailed measurements of the Amazon Basics "192 kHz" Toslink optical and Coax input DAC. I purchased it on member suggestion and costs US $14.

Can't expect more given the price and functionality. As noted there are dual inputs (NO USB -- USB is for power only):

An RCA to 3.5mm adapter cable is included presumably for headphone use.

It is interesting to see full regulatory certification and manufacturing in Vietnam:

I would think if it is just a rebranded generic DAC, it would have come from China.

Amazon Basics DAC Measurements
As usual, we start with our Dashboard, feeding the DAC a 1 kHz digital tone:

I hoped for 96 dB but got 85 dB SINAD (relative sum of noise+distortion). This puts the unit solidly in the "poor" category of all DACs tested:

I was sad to see just 1 volt output. This definitely impacts any headphone listening and makes it less compatible with devices out there.

Noise floor is high by our standards but good enough for the target application:

Someone forgot to enable the output filter (or implement one):

Low level linearity is lost due to noise:

Intermodulation distortion vs level shows that it does do better at max volume than a typical (low performance) phone headphone dongle:

Jitter disturbances are quite low but that is likely due to very high noise floor hiding them:

The biggest issue was when I swept the digital input tone:

The lack of filtering is the reason at high frequencies the graph goes off the chart (the green line at 96 kHz sampling reduces this impact). So we could "forgive" that but not the rise in low frequency distortion. SINAD drops to 50 at 20 Hz! Usually this is caused by poor power supply design. They have the room here to do a good job but obviously they did not to hit a cost target or didn't know better.

I tried to run the Multitone test which is at 192 kHz but could not get the unit to accept that over either Coax or Toslink. The mention of that in the product name is therefore improper. The DAC chip no doubt supports 192 kHz but there is no way to feed it such a digital signal.

Conclusions
There are some signs of quality here given the regulatory certifications and such. I am sure that was part of the product requirement doc (PRD) Amazon gave to whoever designed this. Sadly they did not know to specify other important bits related to fidelity, resulting in a device that clearly could have been better but is not. No doubt it spits out sound though so as a "throw away" product, it works.

In this site, my goal is to find best in class product and sadly, the Amazon Basics DAC is not it. As such, I cannot recommend it.

-----------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

 

[solderdude]

I would think if it is just a rebranded generic DAC, it would have come from China.

It says... Vietnam on the device.
I use the same one (not Amazon) so I can easily extract the audio from a Samsung TV which only has optical audio out to run it to some cheap active desktop speakers to get decent sound.
Once I had to unplug the power when one channel stops giving sound.
Other than that hey work fine otherwise and do their job. I don't think anyone will be using this as a serious DAC though.
Thanks for testing.

Multitone not measured ?

I voted fine... as it is fine for what it is intended to do at this price.

 

[charleski]

Finally! Now the masses can experience the sublime delights of NOS!

 

[Doodski]

It might make a decent project box for somebody.

 

[JSmith]

Yeah this is the same as all those little converter boxes... this is just an Amazon re-badge of same, they wouldn't have had it designed at all.

Was also hoping for slightly better performance even at this price, however good to know these serve their purpose at the very least, but otherwise are worse than average in general. No hidden gem here.


JSmith

 

[GWolfman]

Not horrible to my surprise! However, it still leaves a lot to be desired. I hope Amazon sees this and makes a version/mark 2.

 

[DanielT]

Not horrible to my surprise! However, it still leaves a lot to be desired. I hope Amazon sees this and makes a version/mark 2.

I agree, just thought to write the same. Pretty close to an ok, I think.Or close or close. That is up to everyone to decide, the results are above.
Think about the price as well.

By the way. That was interesting! Thanks for the test Amir.

 

[solderdude]

Finally! Now the masses can experience the sublime delights of NOS!

It oversamples so is not NOS (is a DS DAC) but does not have any digital filtering.
Only in produced ultrasonic crap it acts as a filterless NOS DAC but not in HF roll-off nor noise.

 

[renaudrenaud]

In par with the TotalDac from a measurements point of view. A bit cheaper anyway.

 

[amirm]

Multitone not measured ?

I noted it wouldn't play it because that test uses 192 kHz sampling.

 

[restorer-john]

@amirm Test the D/A for DC offset. That will be what is throwing your THD vs Freq at the low end.

Most of those $10 D/As have no buffer or blocking capacitor and the output comes straight out of the D/A chip itself. The ones I tested had up to 0.5V offset on the L/R RCAs.

 

[Herbert]

Those rebranded devives must be around for a decade now. Mine heavily distorted on this track containing overtone singing when
the Overtones became dominant.

 

[restorer-john]

Finally! Now the masses can experience the sublime delights of NOS!

Filterless, not NOS.

 

[AndreaT]

This does not waste a lot of your money but…it wastes your time, the only truly non-renewable commodity. I’ll pass.

 

[777]

CE is not Conformite Europeenne. That CE is China Export mark

 

[peanuts]

there is so such thing as "china export" according to the EU

"The Commission responded that it was unaware of the existence of any "Chinese Export" mark and that, in its view, the misunderstanding had arisen because a producer had failed to respect the precise dimensions and proportions of the mark as prescribed in the legislation.[15] The Commission was also aware of fraudulent misuse of the mark on products that did not comply with the standards, but that this is a separate issue."

CE marking - Wikipedia

en.wikipedia.org

 

[daftcombo]

In par with the TotalDac from a measurements point of view. A bit cheaper any way.

Actually the totaldac might be the same product put at the center of a big box.

 

[charleski]

It oversamples so is not NOS (is a DS DAC) but does not have any digital filtering.
Only in produced ultrasonic crap it acts as a filterless NOS DAC but not in HF roll-off nor noise.

The audiophile terminology is, unsurprisingly, imprecise and confusing. Any sort of resampling will, by definition, implement a filter, but the filter design (most importantly length) determines how competent it is (how much it rejects out-of-band signals). A decent modern DS DAC has several different stages of oversampling that implement different filters, as seen in fig 18.8 from Pohlman's book:

It's the first oversampling block that performs the alias-rejection filtering (and typically some noise-shaping). In terms of the history of digital audio, such oversampling was introduced very early with R2R DACs. The venerable TDA1541 that pops up is so many 'NOS' designs was actually designed to be used with the SAA7220 digital filter, which oversampled to 176kHz. But the SAA7220 had a lot of problems with jitter due to coupling between the clock and filter supplies and some designers stumbled on the bright idea of ripping it out completely. And boom, 'NOS' was born. There's a DAC design on DIYAudio that implements a 'NOS' DAC using a delta-sigma chip by bypassing the integrated first-stage filter. Obviously oversampling is happening further down the line, but it replicates the conceptual basis, though it's only interesting as a demonstration. A sigma-delta DAC that doesn't have a proper oversampling/shaped filter will display quantisation noise rising at 6dB/octave, which seems very close to what Amir showed here, so I suspect they're doing something similar.

Of course retro-tech audiophiles tend to go all-in on their obsession with obsolete technology, and most these days would insist that a 'NOS' DAC has to be R2R as well. This one probably wouldn't pass muster as providing the true, magical 'NOS' sound, but frankly I find it difficult to care.

 

[solderdude]

Thanks for your explanation.
A modern DS DAC is not like the book example you posted.
This DAC performs nor sounds anything like a NOS DAC, nor a filterless NOS DAC.
It is just a cheap device that lets you use TOSLINK or (caox)SPDIF.

Ferdinand Keil | What's inside a cheap TOSLINK, S/PDIF to Cinch adapter

 

[respice finem]

This is a review and detailed measurements of the Amazon Basics "192 kHz" Toslink optical and Coax input DAC. I purchased it on member suggestion and costs US $14.
View attachment 182186

Can't expect more given the price and functionality. As noted there are dual inputs (NO USB -- USB is for power only):
View attachment 182187
An RCA to 3.5mm adapter cable is included presumably for headphone use.

It is interesting to see full regulatory certification and manufacturing in Vietnam:
View attachment 182188

I would think if it is just a rebranded generic DAC, it would have come from China.

Amazon Basics DAC Measurements
As usual, we start with our Dashboard, feeding the DAC a 1 kHz digital tone:

View attachment 182189

I hoped for 96 dB but got 85 dB SINAD (relative sum of noise+distortion). This puts the unit solidly in the "poor" category of all DACs tested:

View attachment 182190

I was sad to see just 1 volt output. This definitely impacts any headphone listening and makes it less compatible with devices out there.

Noise floor is high by our standards but good enough for the target application:

View attachment 182192

Someone forgot to enable the output filter (or implement one):
View attachment 182193

Low level linearity is lost due to noise:


View attachment 182194

Intermodulation distortion vs level shows that it does do better at max volume than a typical (low performance) phone headphone dongle:

View attachment 182195

Jitter disturbances are quite low but that is likely due to very high noise floor hiding them:

View attachment 182196

The biggest issue was when I swept the digital input tone:

View attachment 182197

The lack of filtering is the reason at high frequencies the graph goes off the chart (the green line at 96 kHz sampling reduces this impact). So we could "forgive" that but not the rise in low frequency distortion. SINAD drops to 50 at 20 Hz! Usually this is caused by poor power supply design. They have the room here to do a good job but obviously they did not to hit a cost target or didn't know better.

I tried to run the Multitone test which is at 192 kHz but could not get the unit to accept that over either Coax or Toslink. The mention of that in the product name is therefore improper. The DAC chip no doubt supports 192 kHz but there is no way to feed it such a digital signal.

Conclusions
There are some signs of quality here given the regulatory certifications and such. I am sure that was part of the product requirement doc (PRD) Amazon gave to whoever designed this. Sadly they did not know to specify other important bits related to fidelity, resulting in a device that clearly could have been better but is not. No doubt it spits out sound though so as a "throw away" product, it works.

In this site, my goal is to find best in class product and sadly, the Amazon Basics DAC is not it. As such, I cannot recommend it.

-----------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

I gave it a "not terrible", since the purpose of these is mostly to get TV sound from Toslink out to an analog amp, or a pair of mostly cheap active speakers. The lack of USB in doesn't matter either for this purpose.