SMSL PO100 PRO Review (Digital Interface)

[bellaireinsure]

I have a couple of them and have used them for various connections/conversions. My favorite is from my Intel NUC that I use as a Roon endpoint to my Geshelli DayZee DAC. The DayZee has a USB interface, but I run the USB from the NUC to the PO 100 Pro, then optical out of the PO 100 Pro to electrically isolate the noisy ancient NUC from the downstream DayZee DAC. It also unfolds the MQA files that remain in Tidal. Not sure that is a big deal, but I think the optical connection and the reclocking are meaningful.

 

[Dumdum]

Did you ever compare the output of the smsl po100 2024 to that of the pro (or other devices like the topping d10s) in the digital domain? I am curious if there are any differences…

I presume as this is digital and I have an interface which takes coax digital in that I can also do these tests with my focusrite 8i6 or 18i20 with coax in also?

I have just been triggered into asking this question because a Facebook user stated that bit perfect output doesn’t mean the signal output is identical to another ddc, there can be differences in jitter, clocking differences and similar

I don’t know enough to reply to him other than an smsl po100 pro is transparent and doesn’t add anything to the signal as far as I’m aware… so I figured I’d ask you clever folk on here

Specifically this statement regarding the topping d10 vs d10s

‘the dac improvements were more substantial, but the spidf output still benefitted from slightly better power filtering on the input side.

bit-perfect just means all of the data from the source file makes it out, without sample rate conversions or dithering, it does not factor clock timing, jitter, etc, there can still be differences in quality between conversion devices, even if the signal is digital on both sides.’

 

[tmtomh]

Did you ever compare the output of the smsl po100 2024 to that of the pro (or other devices like the topping d10s) in the digital domain? I am curious if there are any differences…

I presume as this is digital and I have an interface which takes coax digital in that I can also do these tests with my focusrite 8i6 or 18i20 with coax in also?

I have just been triggered into asking this question because a Facebook user stated that bit perfect output doesn’t mean the signal output is identical to another ddc, there can be differences in jitter, clocking differences and similar

I don’t know enough to reply to him other than an smsl po100 pro is transparent and doesn’t add anything to the signal as far as I’m aware… so I figured I’d ask you clever folk on here

Specifically this statement regarding the topping d10 vs d10s

‘the dac improvements were more substantial, but the spidf output still benefitted from slightly better power filtering on the input side.

bit-perfect just means all of the data from the source file makes it out, without sample rate conversions or dithering, it does not factor clock timing, jitter, etc, there can still be differences in quality between conversion devices, even if the signal is digital on both sides.’

The DAC will reclock the signal. And the jitter from these reputable/already-tested devices is quite low, well below the level where they could cause any downstream problems - and if they did cause problems it wouldn't be subtle sound-quality problems but rather the DAC would have trouble staying locked on to the digital bitstream and/or there would be glitches or dropouts.

Finally, don't the PO100 and PO100 Pro use the same core chipset to do the digital conversion/switching and such?

 

[Dumdum]

The DAC will reclock the signal. And the jitter from these reputable/already-tested devices is quite low, well below the level where they could cause any downstream problems - and if they did cause problems it wouldn't be subtle sound-quality problems but rather the DAC would have trouble staying locked on to the digital bitstream and/or there would be glitches or dropouts.

Finally, don't the PO100 and PO100 Pro use the same core chipset to do the digital conversion/switching and such?

I don’t know, this is why I’m asking @NTTY if he has specifically measured and compared

 

[tmtomh]

I don’t know, this is why I’m asking @NTTY if he has specifically measured and compared

If you’re referring to my final question, we don’t need NTTY’s tests for that, valuable and useful as those are. The PO100 and PO100 Pro both use the XMOS XU316. Why would you listen to “soneone on Facebook” who hand-waves about jitter - at least ask them to back up that general fear-mongering with some examples or data. People trot out this stuff all the time: jitter, slew rate, crossover distortion, and a whole range of other things that are very real things but which rarely are sufficiently high/low/bad to cause any remotely audible difference.

 

[Dumdum]

If you’re referring to my final question, we don’t need NTTY’s tests for that, valuable and useful as those are. The PO100 and PO100 Pro both use the XMOS XU316. Why would you listen to “soneone on Facebook” who hand-waves about jitter - at least ask them to back up that general fear-mongering with some examples or data. People trot out this stuff all the time: jitter, slew rate, crossover distortion, and a whole range of other things that are very real things but which rarely are sufficiently high/low/bad to cause any remotely audible difference.

I wouldn’t, I’d seek out objective data… do you have any?

If not I’m going to measure myself hence me asking the OP if he has measured the devices I mention in the digital domain… why should I give any more weight to what you say vs someone else who claims to know something unless you have objective data to go along with it as you just suggested

 

[tmtomh]

I wouldn’t, I’d seek out objective data… do you have any?

If not I’m going to measure myself hence me asking the OP if he has measured the devices I mention in the digital domain… why should I give any more weight to what you say vs someone else who claims to know something unless you have objective data to go along with it as you just suggested

I only addressed the part about whether the two use the same chip to do the processing. They do.

 

[john61ct]

PO100 vs PO100 Pro are comparably excellent in "SQ performance". IOW transparent digital signal conversion with no measurable degradation, as is usually the case with even cheap DDCs.

If you need UAC 1.0 vs UAC 2.0 switching get the OG.

If you need the added I2S output or if you think you want the higher resolution, get Pro.

That is all, the rest audiofoolery

 

[RandomEar]

@Dumdum The units were compared by @VintageFlanker in this thread.

TLDR:

After hours of repeatability, I would easily proclaim all three units to perform the same.

 

[NTTY]

Did you ever compare the output of the smsl po100 2024 to that of the pro (or other devices like the topping d10s) in the digital domain? I am curious if there are any differences…

No I don’t have the non-pro version.

I presume as this is digital and I have an interface which takes coax digital in that I can also do these tests with my focusrite 8i6 or 18i20 with coax in also?

Probably yes. You’ll need to slave the Focusrite to incoming SPDIF, if that is an option (else it’s by default).

I have just been triggered into asking this question because a Facebook user stated that bit perfect output doesn’t mean the signal output is identical to another ddc, there can be differences in jitter, clocking differences and similar

In that sentence, "similar" would need to be explained.
But yes, besides SPDIF subframes content that should be identical from a device to another, unless there is digital processing before sending (or errors), there could be clock deviation since it is embedded in the SPDIF and transmitted to the receiving device. The receiving device must synchronize to the signal and therefore will suffer clock deviation from the emitter. I’ve never measured that type of deviation to be high enough to generate audible distortion.
The PO100 Pro has a high precision clock, and I could not measure any trace of jitter when it was communicating with my Motu interface, like I showed in the review (very high precision measurement at full 24bits compared to the WAV file).

I don’t know enough to reply to him other than an smsl po100 pro is transparent and doesn’t add anything to the signal as far as I’m aware… so I figured I’d ask you clever folk on here

Specifically this statement regarding the topping d10 vs d10s

‘the dac improvements were more substantial, but the spidf output still benefitted from slightly better power filtering on the input side.

This makes no sense, so I can’t comment, but I suppose it’s out of context.

bit-perfect just means all of the data from the source file makes it out, without sample rate conversions or dithering, it does not factor clock timing, jitter, etc, there can still be differences in quality between conversion devices, even if the signal is digital on both sides.’

Again, not sure what is meant here, but I’ve not measured any deviation with the PO100 Pro. Again, that might be taken out of context.