Jump to content
IGNORED

A novel way to massively improve the SQ of computer audio streaming


Message added by The Computer Audiophile

Important and useful information about this thread

Posting guidelines

History and index of useful posts

Most important: please realize this thread is about bleeding edge experimentation and discovery. No one has The Answer™. If you are not into tweaking, just know that you can have a musically satisfying system without doing any of the nutty things we do here.

Recommended Posts

10 minutes ago, rickca said:

 

Does SOtM claim there is a benefit from clocking multiple components from the same sCLK-EX board compared to the same components with independent sCLK-EX boards?  

 

That would mean an sMS-200 with a 2 transplanted clock points from a tX-USBultra would outperform independent sMS-200ultra and tx-USBultra.

 

Maybe you didn't have this in mind when you said 'same master clocking board'.  If you are instead referring to SOtM 10MHz external master clock synchronization, nobody has heard that yet.

 

 

Yes, read back on Romaz comments from Munich show talking with SoTM reps.  There is a built in master clock to the sCLK EX board, but they say an external master clock hooked up to the board would be even better (Note: they are working on their own, so get the external input).  Also you can use the same clock for multiple components needing that setting.

(JRiver) Jetway barebones NUC (mod 3 sCLK-EX, Cybershaft OP 14)  (PH SR7) => mini pcie adapter to PCIe 1X => tXUSBexp PCIe card (mod sCLK-EX) (PH SR7) => (USPCB) Chord DAVE => Omega Super 8XRS/REL t5i  (All powered thru Topaz Isolation Transformer)

Link to comment
1 hour ago, rickca said:

 

Does SOtM claim there is a benefit from clocking multiple components from the same sCLK-EX board compared to the same components with independent sCLK-EX boards?  

 

That would mean an sMS-200 with a 2 transplanted clock points from a tX-USBultra would outperform independent sMS-200ultra and tx-USBultra.

 

Maybe you didn't have this in mind when you said 'same master clocking board'.  If you are instead referring to SOtM 10MHz external master clock synchronization, nobody has heard that yet.

 

 

 

Yes, this is a very good point.  From my understanding, traditional master clocks can degrade quality for small runs such as what we have at home.  This information, from sound recording engineers not made up by me, could be dated or based on other factors.  If a master clock does in fact provide an improvement in quality that exceeds the benefit of only placing a superior clock as the last before the DAC, then there would be benefit in using a true master at the beginning of the chain, all the way through to the end.  It could also be that using a master slave at any point within the chain in addition to the superior clock as the last before the DAC provides the best possible quality.

 

Lots of ad hoc testing and we'd all really benefit from someone like Lee at SOtM to provide us with this info.  Since people are doing this on their own at home, actual measurement tools like a jitter meter would benefit in addition to the "it sounds better" statement.  We are all trusting of those opinions who are doing the home tests and it's to our benefit because something is better than nothing at this point.  However I am loathe to invest thousands when I hear information from Lee stating he sees high jitter in a configuration and we either didn't hear it or don't know what to listen for.

Link to comment

Here is what May said about the regulator modification that Roy discussed with Lee at Munich:

 

Listening condition

- Powered by sPS-1000 output no.3 at 5V and 7V

- DC cable : 7N UPOCC copper cable

- The 5V version kept the same capacitors as the original version(6.5V~9V), and bypassed the DC-DC converter.

 

sMS-200 5V input version : It sounded relatively live and active, but the band balance sounds a bit lack.

sMS-200 6.5V ~ 9V input version : It sounded relatively serious and like calm, but the band balance is better.

 

In conclusion, the sound and test result can be variable by what power supply and dc cable are used and also by personal sound taste. But IMHO, this sound difference is difficult to judge which one is better or not, for some people, the 5v version can be good but for some others, keeping the standard power condition can be good.

But in overall, putting the tX-USBultra between the sMS-200(doesn’t matter which power version is) and the DAC, this is the best sound

Link to comment
5 minutes ago, limniscate said:

Here is what May said about the regulator modification that Roy discussed with Lee at Munich

What is meant by 'band balance'?

 

Is this sMS-200 regulator mod also an option on the sMS-200ultra?

Pareto Audio AMD 7700 Server --> Berkeley Alpha USB --> Jeff Rowland Aeris --> Jeff Rowland 625 S2 --> Focal Utopia 3 Diablos with 2 x Focal Electra SW 1000 BE subs

 

i7-6700K/Windows 10  --> EVGA Nu Audio Card --> Focal CMS50's 

Link to comment
1 minute ago, rickca said:

What is meant by 'band balance'?

 

Is this sMS-200 regulator mod also an option on the sMS-200ultra?

 

I believe it's available on the tX, dX, sMS-200, and sMS-200 Ultra.  I'm not exactly sure what "band balance" means as well.

Link to comment

May quoted me an extra £30 in the UK to have a SMS-200 Ultra built without the first regulator.

SOtM sMS-200ultra (12v, silver internal DC cable, 75Ω external clock input),

SOtM tX-USBultra (12v, silver internal DC cable, 75Ω external clock input),

Singxer SU-1 (7v SOtM sCLK-EX, silver internal DC cable, 75Ω external clock input),

W4S DAC2v2 SE (SOtM sCLK-EX silver internal DC cable, 75Ω external clock input),

Mutec REF 10, Bryston BP6, Trinnov Altitude 32, 9 x Bryston 7B³s, B&W 800D3s, B&W HTM1 D3, 2 x Arendal Sub 3,

SOtM dCBL-CAT7 (ISO-CAT6 SE), SOtM eABS-200 installed on all components, JCAT NET Card FEMTO, mRendu, dCS Rossini DAC, Chord Hugo 2, Schitt Yggy, Chord Qutest (ordered for home office), UpTone ISO Regen, 5 x UpTone LPS-1s, 4 x PH SR4s, 5 x UpTone LPS-1.2s

Link to comment

I'm still undecided if I should update my order or just leave it at 12V, I will be powering it with a PH SR7MR4XL.

SOtM sMS-200ultra (12v, silver internal DC cable, 75Ω external clock input),

SOtM tX-USBultra (12v, silver internal DC cable, 75Ω external clock input),

Singxer SU-1 (7v SOtM sCLK-EX, silver internal DC cable, 75Ω external clock input),

W4S DAC2v2 SE (SOtM sCLK-EX silver internal DC cable, 75Ω external clock input),

Mutec REF 10, Bryston BP6, Trinnov Altitude 32, 9 x Bryston 7B³s, B&W 800D3s, B&W HTM1 D3, 2 x Arendal Sub 3,

SOtM dCBL-CAT7 (ISO-CAT6 SE), SOtM eABS-200 installed on all components, JCAT NET Card FEMTO, mRendu, dCS Rossini DAC, Chord Hugo 2, Schitt Yggy, Chord Qutest (ordered for home office), UpTone ISO Regen, 5 x UpTone LPS-1s, 4 x PH SR4s, 5 x UpTone LPS-1.2s

Link to comment
3 minutes ago, Johnseye said:

 

They should have quoted you less since they save cost on material and labor.

:) I also think the Ultra version should come with the Master Clock connector as standard not $200 extra.

 

I don't understand how that option costs so much.

SOtM sMS-200ultra (12v, silver internal DC cable, 75Ω external clock input),

SOtM tX-USBultra (12v, silver internal DC cable, 75Ω external clock input),

Singxer SU-1 (7v SOtM sCLK-EX, silver internal DC cable, 75Ω external clock input),

W4S DAC2v2 SE (SOtM sCLK-EX silver internal DC cable, 75Ω external clock input),

Mutec REF 10, Bryston BP6, Trinnov Altitude 32, 9 x Bryston 7B³s, B&W 800D3s, B&W HTM1 D3, 2 x Arendal Sub 3,

SOtM dCBL-CAT7 (ISO-CAT6 SE), SOtM eABS-200 installed on all components, JCAT NET Card FEMTO, mRendu, dCS Rossini DAC, Chord Hugo 2, Schitt Yggy, Chord Qutest (ordered for home office), UpTone ISO Regen, 5 x UpTone LPS-1s, 4 x PH SR4s, 5 x UpTone LPS-1.2s

Link to comment

Improving USB Audio

http://www.johnkenny.biz/home-1/announcements/improvingusb

 

http://www.tirnahifi.org/forum/viewtopic.php?f=15&t=3618&start=150

Quote

You might be interested in the just launched ISO-PS an isolated power supply using LiFePO4 batteries
Outputs one or two 3.3V independent supplies or combined to give one 6.6V supply (other voltages can be considered - just ask) - perfect for pwerig many audio devices - see my signature for website
Internal battery chargers are isolated from power supply so no bleed through of noise from leakage currents or ground loops
Fully automatic - just plug in & forget

 

http://www.tirnahifi.org/forum/viewtopic.php?f=15&t=3640&start=190

Quote

You know you could replace "JCAT Intona => USB adapter (with silver wires) => Ifi 2 USB => Regen (JK moded)" with a nice neat ISO-HUB which houses a USB isolator (better than Intona) + USB reclocker/reformer (better than Regen even battery powered) & all running off 2 LiFePO4 batteries with chargers, all cased up in a black case

 

ISO-PS for €250

 

http://www.ciunas.biz/product-page/iso-ps

 

ISO-HUB for €450

 

http://www.ciunas.biz/product-page/iso-hub-external-power

 

Just found something new today, now the question is how good would genuine A123 Systems LiFePO4 with ISO-PS actually sound when compared to LPS-1 etc.

 

http://www.a123systems.com/lifepo4-battery-cell.htm

http://www.a123systems.com/lithium-iron-phosphate-battery.htm

http://www.batteryspace.com/A123-System-Nanophosphate-LiFePO4-18650-Rechargeable-Cell-3.2V-1100mAh.aspx

 

A123 Lithium Nanophosphate

https://www.audioasylum.com/forums/pcaudio/messages/7/77068.html

 

Batteries in Audio

http://rockgrotto.proboards.com/thread/5941/batteries-audio

Link to comment

Here's some very good, simple info on master clocking.  It's from a recording studio perspective so keep in mind the AD references, but the same principles apply.  The only caveat I can think of is that with the increasing number of devices we are utilizing in these chains, that drift occurs and can't be recovered.  This should be an indicator to simplify, not add more devices.

 

http://www.soundonsound.com/techniques/does-your-studio-need-digital-master-clock

 

And to summarize key points.

 

"The issue here is that it is much easier to design a good clock circuit using a fixed crystal inside the unit than it is to design a circuit which accepts an external clock signal and synchronises to it well. External clocks are likely to acquire some element of jitter (largely because of the inherent effects of clock cabling), and the common slave‑locking circuits can introduce further timing variations of their own, both of which can be quite hard (and expensive) to remove. As a result, an A‑D will often perform less well when synchronised to an external clock than when it is running on its own internal crystal. The noise floor may rise, and there may be more low‑level distortion products and artifacts. That being the case, it makes sense to use a device which can handle external clocks well as the slave, and a device which works poorly on external clocks as the master. In that way, the maximum audio quality can be achieved for all devices."

 

I already posted the information on interface jitter from this article in a previous post, but here's some critical information to consider when the SOtM uses 75ohm BNC interfaces for the clock chain.  I would expect Lee to ensure this does not occur with their interfaces.

 

"It's also critically important to terminate word clock signals correctly. The word clock input terminal (normally a BNC connector) on some devices is deliberately unterminated (high impedance), while some are permanently terminated and others are switchable. If the line is unterminated, the clock signal will be reflected back down the cable, which could prevent some devices from detecting and locking onto the word clock information. The usual way to apply a termination in these cases (as shown by the diagram, left) is to fit a BNC T‑piece to the word clock input terminal, attach the clock cable to one side and a 75Ω termination plug to the other. Double terminations (where an extra termination is added inadvertently to one already on the line) will result in a low-level signal with the same potential problem."

Conclusions

Overall, it should be clear from these tests that employing an external master clock cannot and will not improve the sound quality of a digital audio system. It might change it, and subjectively that change might be preferred, but it won't change things for the better in any technical sense. A‑D conversion performance will not improve: the best that can be hoped for is that the A‑D conversion won't become significantly degraded. In most cases, the technical performance will actually become worse, albeit only marginally so.

Having said all this, the use of a master clock may well make a digital audio system much more convenient and stable to operate — and that may well be a very desirable benefit in its own right, easily outweighing any minor performance compromises of slaved A‑D converters. Or it may ensure the required synchronism between sample rates and video frames is achieved, which is absolutely vital in any video‑related work.

The obvious conclusion is that in simple digital audio setups a master clock is usually unnecessary, although it remains critical that multiple digital devices are clocked sensibly. In more elaborate digital audio systems, a master clock can make the task of slaving multiple units much easier and neater, and allow the system to operate more reliably. In systems where digital audio is being used in synchronism with video, an appropriate master clock is absolutely essential. But in any of these cases, the use of a master clock will not improve the audio quality achieved by the converters in any technical sense — and the most expensive clocks fare no better in this regard than the least expensive. The only relevant criteria for purchase is whether the clock provides the facilities, inputs and outputs required, and is designed sufficiently well to conform with AES11 Grade 1 standard.  

Link to comment
55 minutes ago, limniscate said:

I just placed my order for 12V dX-USB Ultra & sMS-200 Ultra both with external master clock option, switch mod, 4 dCBL-CAT7, 2 iSO-CAT6.

Wow, that's confidence!  I guess you have heard some of this for yourself with @austinpop, right? 

Pareto Audio AMD 7700 Server --> Berkeley Alpha USB --> Jeff Rowland Aeris --> Jeff Rowland 625 S2 --> Focal Utopia 3 Diablos with 2 x Focal Electra SW 1000 BE subs

 

i7-6700K/Windows 10  --> EVGA Nu Audio Card --> Focal CMS50's 

Link to comment
On 19 May 2017 at 3:36 AM, austinpop said:

 

Tommy, the best would be to contact May and inquire. They're pretty open to doing mods, but the extent to which they would know ahead of time what's feasible just depends on whether they've had any prior experience with the unit.

 

I sent them a Zyxel GS108Bv3. I really wanted to use a 5-port, but had trouble sourcing it. I was alerted to this switch model by Roy as he recalled it was the baseline Paul Pang used to use. More recently, it looks like Pang and Aqvox are using D-Link DGS-2208 (?) switches, so those may be good to use too. 

 

My main criteria was also to pick a switch whose DC voltage requirements were in the right range and whose power needs were modest, so it could share power from an LPS-1 at 7V with the modded sMS-200.

 

Finally, if you are buying everything else new, it may be possible to ask SOtM to source the switch, so you don't have to ship them anything. I believe @limniscate was pursuing that with them.

Rajiv, I have sourced a 5 port Zyxel switch GS105B V3 which I intend to buy but it seems it requires a 9v, which I believe is the same requirement of your switch "Zyxel GS108B V3".

 

However, the above mentioned Dlink switch requires 5V. So I'm kinda confused..

Link to comment
6 hours ago, limniscate said:

Obviously, I didn't like reading @Johnseye's post about master clocks since I just ordered the external master clock option for both the dX and the sMS.

 

You get to decide for yourself and you can run it with or without.  It will be interesting to know what you hear.  If you have the ability to blind our double blind test that would help eliminate any bias. It's easy to do if you have someone you trust with your gear to help.

Link to comment
7 hours ago, Narcissus said:

Rajiv, I have sourced a 5 port Zyxel switch GS105B V3 which I intend to buy but it seems it requires a 9v, which I believe is the same requirement of your switch "Zyxel GS108B V3".

 

However, the above mentioned Dlink switch requires 5V. So I'm kinda confused..

 

Hmm, my GS108b v3 requires 5V. See the picture here: https://www.zyxel.com/uk/en/products_services/8-Port-Desktop-Gigabit-Ethernet-Switch-GS-108B-v3/

 

I asked May, as part of replacing the stock regulators, to use linear regulators that would allow me to supply 7v. They (SOtM) asked me to limit the number of ports used to 2-3, which is exactly my use case.

 

My switch runs very cool, so ive had no issues with excessive heat at this voltage.

Link to comment
19 hours ago, Johnseye said:

Here's some very good, simple info on master clocking.  It's from a recording studio perspective so keep in mind the AD references, but the same principles apply.  The only caveat I can think of is that with the increasing number of devices we are utilizing in these chains, that drift occurs and can't be recovered.  This should be an indicator to simplify, not add more devices.

 

http://www.soundonsound.com/techniques/does-your-studio-need-digital-master-clock

 

And to summarize key points.

 

"The issue here is that it is much easier to design a good clock circuit using a fixed crystal inside the unit than it is to design a circuit which accepts an external clock signal and synchronises to it well. External clocks are likely to acquire some element of jitter (largely because of the inherent effects of clock cabling), and the common slave‑locking circuits can introduce further timing variations of their own, both of which can be quite hard (and expensive) to remove. As a result, an A‑D will often perform less well when synchronised to an external clock than when it is running on its own internal crystal. The noise floor may rise, and there may be more low‑level distortion products and artifacts. That being the case, it makes sense to use a device which can handle external clocks well as the slave, and a device which works poorly on external clocks as the master. In that way, the maximum audio quality can be achieved for all devices."

 

I already posted the information on interface jitter from this article in a previous post, but here's some critical information to consider when the SOtM uses 75ohm BNC interfaces for the clock chain.  I would expect Lee to ensure this does not occur with their interfaces.

 

"It's also critically important to terminate word clock signals correctly. The word clock input terminal (normally a BNC connector) on some devices is deliberately unterminated (high impedance), while some are permanently terminated and others are switchable. If the line is unterminated, the clock signal will be reflected back down the cable, which could prevent some devices from detecting and locking onto the word clock information. The usual way to apply a termination in these cases (as shown by the diagram, left) is to fit a BNC T‑piece to the word clock input terminal, attach the clock cable to one side and a 75Ω termination plug to the other. Double terminations (where an extra termination is added inadvertently to one already on the line) will result in a low-level signal with the same potential problem."

Conclusions

Overall, it should be clear from these tests that employing an external master clock cannot and will not improve the sound quality of a digital audio system. It might change it, and subjectively that change might be preferred, but it won't change things for the better in any technical sense. A‑D conversion performance will not improve: the best that can be hoped for is that the A‑D conversion won't become significantly degraded. In most cases, the technical performance will actually become worse, albeit only marginally so.

Having said all this, the use of a master clock may well make a digital audio system much more convenient and stable to operate — and that may well be a very desirable benefit in its own right, easily outweighing any minor performance compromises of slaved A‑D converters. Or it may ensure the required synchronism between sample rates and video frames is achieved, which is absolutely vital in any video‑related work.

The obvious conclusion is that in simple digital audio setups a master clock is usually unnecessary, although it remains critical that multiple digital devices are clocked sensibly. In more elaborate digital audio systems, a master clock can make the task of slaving multiple units much easier and neater, and allow the system to operate more reliably. In systems where digital audio is being used in synchronism with video, an appropriate master clock is absolutely essential. But in any of these cases, the use of a master clock will not improve the audio quality achieved by the converters in any technical sense — and the most expensive clocks fare no better in this regard than the least expensive. The only relevant criteria for purchase is whether the clock provides the facilities, inputs and outputs required, and is designed sufficiently well to conform with AES11 Grade 1 standard.  

 

This is an interesting article, and reinforces what I had previously read about master clocks, and why I had never really dabbled in this space. It's only when Roy described his findings with the sCLK-EX that my interest was piqued. And now, having experienced the SQ first hand, I am sold on the benefits of a superior clock.

 

I should preface the next remarks by saying that I am not an expert, nor even very informed, in the realm of digital audio clocks.

 

The clock distribution that Roy, I, and others have achieved with the configuration like mine, shown below, is not a master clock topology. In a master clock topology, each device has its own independent master clock, that generates all the required frequencies within the device. In addition, it has the ability to slave to an external master clock, when one is connected to its master clock input. This input is at a standard frequency of 10MHz (from what I've seen). The internal master clock, now a slave, synchronizes to this master clock, but still generates the derived frequencies within the device itself.

 

Capture-2.thumb.PNG.1f3040f577464f47e39bef3ab8596400.PNG

 

In contrast, in our sCLK-EX topology, there is only one master clock across all three devices. The sCLK-EX board in the tX-USBultra is generating clocks for all the devices. As part of the mods, the default clocks in the switch and the sMS-200 are replaced by clock signals sent from the sCLK-EX board. Without the tX-USBultra, and hence the sCLK-EX board powered on and active, the switch and sMS won't even function. These clock signals are at the required frequencies for the specific devices. If I remember correctly, its 24 and 25MHz.

 

Clearly, by keeping these clock wires short - 20cm in my case - whatever jitter is added by the clock wires does not significantly detract from the SQ improvements.

 

 

Here's what we don't know. If, in this topology, the sCLK-EX board in the tX-USBultra now becomes the slave to an "even better master clock" like the Mutec Ref10, or the as-yet-unannounced SOtM master clock, will this actually improve the SQ? Or will the well-known concerns about master clocks, as described in the referenced article, come into play and render the master clock improvements moot?

 

Only time - and our ears - will tell.

 

Link to comment
9 hours ago, limniscate said:

Obviously, I didn't like reading @Johnseye's post about master clocks since I just ordered the external master clock option for both the dX and the sMS.

 

Eric,

 

See my post immediately above. You're still locking in the sCLK-EX improvements.

 

The only thing you don't know is whether, in the future, if you buy an amazing master clock like the Ref 10, you will hear an additional improvement. That will determine whether the extra - what, $200? - you spent for the master clock inputs was worth it or not.

Link to comment

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



×
×
  • Create New...