This is a review and measurements of the Fosi S3 streamer and DAC. It was sent to me by the company and costs US $260.
The labels are hard to read but otherwise, the unit fits the "ID" of other Fosi products. What put a smile on my face was not the front, but the back:
Did not expect the XLR balanced outputs! There is also S/PDIF out allowing you to use an external DAC. Inclusion of Trigger out to power on your amplifier is also a very nice touch.
There is an app to control it as well as a remote control. Power is provided by a small switching power supply, double the size of the typical mobile phone charger.
Support for streaming protocol at this point is limited. Roon is waiting for certification. And Chromecast in my testing truncated to 16 bits. Airplay and UPnP is provided the latter of which I used for my testing.
Fosi S3 Streamer Measurements
As usual, we start with our dashboard, streaming UPnP from my desktop over Ethernet:
I tested Toslink input and got the same excellent results:
Dynamic range is very nice for class:
As is Multitone intermodulation test:
Noise floor in jitter test is not state of the art but again, very good for this category of product:
Finally, we have our typical filter roll off with excellent attenuation above 24 kHz for CD sampling:
Since my analyzer can't control streaming devices, this is all that I could (easily) test.
Addendum: additional tests.
I ran some sweeps for the DAC using Toslink (streaming should be the same).
IMD:
As noted, it is very nice for the class. There are no "humps" and output is as expected.
THD+N vs Frequency:
This is good. Of course, it is not state of the art but neither is the device in that class.
This is the dashboard using RCA Out:
Nearly the same as XLR.
Analog Preamp:
I tested RCA in, XLR Out:
At nearly 100 dB, the SINAD is much better than I expected. RCA performance is the same:
Notice how the output is properly 2 volts for RCA and 4 volts for XLR. So you get unity gain for either output.
Finally, I tested digital in, digital out (Toslink in both cases):
I turned off dither in the generator, giving is ideal, 24-bit, bit-exact output.
Furthermore, the output can be adjusted with volume control! This means you can drive a DAC without volume control, or an active speaker with Toslink digital input.
Really good results.
Conclusions
I must say, I did not expect Fosi to jump into streaming domain given the heavy software burden that brings with it. They have licensed the core technology which eases entry but also causes delays in bug fixes and feature enhancements. We see some of that effect here but what is there is quite solid. Measured performance is excellent as is support for my favorite, balanced output. Value is quite high given the price point.
I am going to give my recommendation to Fosi S3 streamer. I would have ranked it the highest levels if it had support for Roon already available.
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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/
The labels are hard to read but otherwise, the unit fits the "ID" of other Fosi products. What put a smile on my face was not the front, but the back:
Did not expect the XLR balanced outputs! There is also S/PDIF out allowing you to use an external DAC. Inclusion of Trigger out to power on your amplifier is also a very nice touch.
There is an app to control it as well as a remote control. Power is provided by a small switching power supply, double the size of the typical mobile phone charger.
Support for streaming protocol at this point is limited. Roon is waiting for certification. And Chromecast in my testing truncated to 16 bits. Airplay and UPnP is provided the latter of which I used for my testing.
Fosi S3 Streamer Measurements
As usual, we start with our dashboard, streaming UPnP from my desktop over Ethernet:
I tested Toslink input and got the same excellent results:
Dynamic range is very nice for class:
As is Multitone intermodulation test:
Noise floor in jitter test is not state of the art but again, very good for this category of product:
Finally, we have our typical filter roll off with excellent attenuation above 24 kHz for CD sampling:
Addendum: additional tests.
I ran some sweeps for the DAC using Toslink (streaming should be the same).
IMD:
As noted, it is very nice for the class. There are no "humps" and output is as expected.
THD+N vs Frequency:
This is good. Of course, it is not state of the art but neither is the device in that class.
This is the dashboard using RCA Out:
Nearly the same as XLR.
Analog Preamp:
I tested RCA in, XLR Out:
At nearly 100 dB, the SINAD is much better than I expected. RCA performance is the same:
Notice how the output is properly 2 volts for RCA and 4 volts for XLR. So you get unity gain for either output.
Finally, I tested digital in, digital out (Toslink in both cases):
I turned off dither in the generator, giving is ideal, 24-bit, bit-exact output.
Furthermore, the output can be adjusted with volume control! This means you can drive a DAC without volume control, or an active speaker with Toslink digital input.
Really good results.
Conclusions
I must say, I did not expect Fosi to jump into streaming domain given the heavy software burden that brings with it. They have licensed the core technology which eases entry but also causes delays in bug fixes and feature enhancements. We see some of that effect here but what is there is quite solid. Measured performance is excellent as is support for my favorite, balanced output. Value is quite high given the price point.
I am going to give my recommendation to Fosi S3 streamer. I would have ranked it the highest levels if it had support for Roon already available.
----------
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/
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