Master Clock for the SOtM SMS-200 Ultra Neo SE

Hi guys

I have the SOtM SMS-200 Ultra Neo SE in a rig with a very well treated digital signal. It sounds very nice, but it doesn't have a Master Clock input because I did not wanted to pay that aditional cost back then (now I kind of regret it as I have a Master Clock).


Has anyone of you tried this device with and without a Master Clock feeding it? Does it really make a noticeable difference? My experience has been that the further the device from the DAC, the less impact the Master Clock makes. The biggest impact is feeding the DAC. I have it also feeding a DDC before the DAC and the Uptone ER and I don't find a big difference, mostly on the ER.


​Please answer if you had a real listening experience. I don't want to start a technical debate. 


Mostly it depends on the DAC.

If you have one that ignores the external clock it is totally silly.

hans beekhuysen has a video review on youtube that addresses the op question directly

Thanks for the answers.


My DAC is being fed by the Clock and it made a noticeable difference on it, but not much on the upper parts of the digital chain. It seems that the further from the DAC, the smaller the impact of a clock.


I will watch Hans SMS-200 Ultra Neo video again. Thanks. I don't remember him talking about this subject in particular.

“Does it really make a noticeable difference?”

The answer to your question is emphatically YES! But you must use a very high quality external Master Clock to hear appreciable improvements.The BNC clock cable quality also matters. If your DAC or Streamer can accept a 10MHz external clock input, it is absolutely worth experimenting. I don’t own SMS-200 but my experience with Aurender N20 fed by external master clock was quite an eye opener. Inspired by this revelation, I am now putting together pieces to try a fully tricked out sNH-10G switch with external master clock and later plan to add Aurender N30SA.

Once you hear a system with a high quality master clock, you will not go back!


Thanks for posting the video. Hans nailed it. But man, he missed the opportunity to kill two birds with one stone, he could have easily asked SOtM to send the switch with external master clock input :-) 

Well, at that time I did not have the master clock and the money.


Maybe I can ask Crux Audio to add it now. We'll see.

If you use Usb in asynchronous mode all that needs clocking is the dac since it slaves the server. On all other protocols except I2S clocking the server matters greatly since it embeds the accurate clock signal that the dac uses.


Thanks for your post and clarification. I keep forgetting majority of folks still using USB or AES/SPDIF to connect their streamer and DAC. I have gone all Ethernet and couldn’t be any happier. 


with pleasure… seems you decided on additional clocking on your ethernet connected equipment as well

Enjoy the music

Answer is yes.  I have SOtM SMS-200, USBultra, Estoteric K-01X, and EtherREGEN all clocked to a 10mHz Stanford Research PERF-10.  The synergy of the whole is greater than its parts. 

@dgarretson That sounds like an amazing setup.

@plga What was your final decision? I am in the same boat as you. I bought the SOtM sMS-200 ultra Neo 2 years ago with no clock input. I am considering adding a 10 MHz external master clock which means I need to replace the Ultra Neo and buy a DAC with clock input. I am also looking at the Gustard R26 streamer / DAC as well.

Well, SOtM USA quoted me $350 for the aditional master clock input and I won’t do it. Originally was $200 when I bough the SMS-200 Ultra Neo.

My experience is that the closer the clock to the DAC the more impact it makes. So, I use the three outputs of the master clock for the DAC, the DDC and the Uptone ER.

I think there are better ways to improve sound for the money as I would also need to spend on a clock with more outputs.

$350 + a new clock is too much.

Well, I think it is a bit excessive but they have to open up your unit, make sure they do not cause any damage, add the clock input, then close up right? So it should cost more than $200 but that's almost double. I will pay the $350 or get another Ultra Neo with all the bells and whistles (Special Edition). I plan to get a clock with 3 or more outputs. Thanks so much for the info!

I have the Special Edition without clock input as it was an open unit with lower price.

Be sure to get it with clock input.

I think there are better ways to improve sound for the money as I would also need to spend on a clock with more outputs.

I think so too.  What DDC and DAC are you using and what connection between them?

I have no DDC as of yet. I am looking at Denafrips Iris, Musician Pisces, and Singxer SU-6. Others? I am using a 10 year old April Music Eximus DP1. Obviously, it has no clock input.

My DAC is the Audio-GD HE-7 and my DDC is the Audio-GD DI-20. The connection between them is I2S.

For a top notch DDC I would recommend Audio-GD DI-20HE over the other ones mentioned above.

@dgarretson Someone made me an offer I couldn't refuse. I just purchased the Esoteric Grandioso D1.

@plga I reached out to both Magna Hifi and SOtM USA to investigate adding a clock input to the sms-200. I just checked my receipt and I did add every option except the clock  input. Do you think I still need the Audio-GD DI-20HE?

Well, the Audio-GD DI-20HE is not a reclocker, it converts the digital signal to a different one that's easier for the DAC to process. 

I would say it depends on how good is the USB input of your DAC.

I'm almost sure it will improve the sound quality, but it would be great if you could try one or any other DDC with your DAC before deciding.

I have pretty much settled on the Cybershaft OP-19 master clock. I will investigate the Audio-GD DI-20HE. It appears to be the best on the market currently.

@zeusodin The Musician Pisces or Leo will both reclock and allow you to take advantage of your DAC’s XLR input (or i2S if your DAC has that input) so it’s like two benefits in one. The Leo has a better clock and also has an SPDIF input that is nice if you have a CD transport, so those might be some things to consider.