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

[flkin]

On asking SOtM about their filters, recently they have been pushing their Sata III over the Sata II filter. And with recent technological improvements with Sata III drives like the Samsung Evo 860 drives consuming very low power and sounding very good even by itself, it’s not surprising they are doing this. 

 

Also the Sata II filters for data are very simple, not sure if they have that much effect. I’ve marked them on the picture below

 

 

[Johnseye]

2 minutes ago, flkin said:

On asking SOtM about their filters, recently they have been pushing their Sata III over the Sata II filter. And with recent technological improvements with Sata III drives like the Samsung Evo 860 drives consuming very low power it’s no wonder why they are doing this. 

 

Also the Sata II filters for data are very simple today, not sure if they have that much effect. I’ve marked them on the picture below

 

 

 

They do have a positive effect.  Without question.

[Johnseye]

On 5/27/2018 at 6:25 PM, lmitche said:

For those of you with Asus Intel motherboards I found this little nougat in the bios manual of my new motherboard:

 

BCLK Spread Spectrum
This item allows you to reduce the EMI. Disable to get more accurate base clocks.
Configuration options: [Auto] [Disabled]

 

Setting it to Disabled is audible, wow!

 

On 5/27/2018 at 8:12 PM, jabbr said:

 

Oh yeah, and for all of y'a who've been hearing improvements with clock replacements and who've had spread spectrum enabled, you need to go back and rethink what and why you are hearing what you are hearing ... jus' sayin'

 

On 5/28/2018 at 3:38 PM, mansr said:

And how does this square with the deep fear of radiated interference, which spread spectrum reduces?

 

So the spread spectrum functionality produces a negative effect on the clock's performance or influence of SQ greater than any benefit it provides in EMI/RF reduction.  @lmitche this is what you are saying is audible when disabling spread spectrum, the negative impact it has on the motherboard clock?

[LTG2010]

1 hour ago, Johnseye said:

So the spread spectrum functionality produces a negative effect on the clock's performance or influence of SQ greater than any benefit it provides in EMI/RF reduction.  @lmitche this is what you are saying is audible when disabling spread spectrum, the negative impact it has on the motherboard clock?

Spread spectrum is a frequency modulation of the original clock signal designed to reduce EMI. Whilst it reduces EMI it also Jitters the original signal to quite a high level and for audio purposes it's not a good idea.

[LTG2010]

On 6/4/2018 at 4:51 PM, Johnseye said:

They do have a positive effect.  Without question.

I tried SOTM's SATA 11 with my intel SSD, whilst I did hear a reduction in background noise I also felt it reduced dynamics a bit, perhaps I was too quick to judge or did not let it burn in properly, but the slc without filter still sounds good. Looking forward to your comparison with the optane drive.

[ElviaCaprice]

1 hour ago, LTG2010 said:

I tried SOTM's SATA 11 with my intel SSD, whilst I did hear a reduction in background noise I also felt it reduced dynamics a bit, perhaps I was too quick to judge or did not let it burn in properly, but the slc without filter still sounds good. Looking forward to your comparison with the optane drive.

That's good to know.  Made me pause in even wanting to try this out.  Not going to make a special order from SOtM for a maybe.

[sandyk]

1 hour ago, LTG2010 said:

I tried SOTM's SATA 11 with my intel SSD, whilst I did hear a reduction in background noise I also felt it reduced dynamics a bit, perhaps I was too quick to judge or did not let it burn in properly, but the slc without filter still sounds good. Looking forward to your comparison with the optane drive.

 

If you have enough room, it's better to use the +12V rail to provide a cleaner and more isolated, voltage regulated +5V supply for the SSD. 

[mansr]

1 hour ago, LTG2010 said:

Spread spectrum is a frequency modulation of the original clock signal designed to reduce EMI. Whilst it reduces EMI it also Jitters the original signal to quite a high level and for audio purposes it's not a good idea.

That's why it isn't used for audio clocks. Neither is it used for USB or Ethernet. There are dozens of clocks in a PC. Spread spectrum settings apply to only a few of them.

[sandyk]

8 minutes ago, mansr said:

That's why it isn't used for audio clocks. Neither is it used for USB or Ethernet. There are dozens of clocks in a PC. Spread spectrum settings apply to only a few of them.

 

 That's good to know, as I don't believe that I have any noticeable problems due to increased Jitter in my PC setup.

P.S.

 How about less time wasted posting , and more time developing your new USB add-on ?

 Perhaps you can come up with something so worthwhile that even sceptical Dennis will try it ?

[lmitche]

36 minutes ago, mansr said:

That's why it isn't used for audio clocks. Neither is it used for USB or Ethernet. There are dozens of clocks in a PC. Spread spectrum settings apply to only a few of them.

I have also noticed controls to disable spread spectrum on the PCIE bus and VRM. So far I've only disabled it on the BLCK with a nice impact.

[rickca]

1 hour ago, mansr said:

That's why it isn't used for audio clocks. Neither is it used for USB or Ethernet. There are dozens of clocks in a PC. Spread spectrum settings apply to only a few of them.

Then why do I see in the specs for the ASMedia 2142

Integrated Spread Spectrum Controller for PCI Express interface

Integrated Spread Spectrum Controller for USB3.1 interface

 

[rafa]

On 6/3/2018 at 9:23 PM, ElviaCaprice said:

  I've yet to give this a go, but others report positive results.

 

I can confirm. I am using Sata III filter. The effect is minimal but important for me. It improves 'timing' in sound if you know what I mean.

[mansr]

8 hours ago, rickca said:

Then why do I see in the specs for the ASMedia 2142

Integrated Spread Spectrum Controller for PCI Express interface

Integrated Spread Spectrum Controller for USB3.1 interface

USB3 has spread spectrum clocking, USB2 doesn't. I have yet to see a DAC with USB3 interface.

[LTG2010]

10 hours ago, mansr said:

That's why it isn't used for audio clocks. Neither is it used for USB or Ethernet. There are dozens of clocks in a PC. Spread spectrum settings apply to only a few of them.

It's a system used to meet FCC regulations, It can effect the OS, CPU and PCIE, the computers power management, hard drives etc. Hence the audible difference Larry has found? There are better ways to reduce emi, IMO - careful attention to ground plane design, faraday cages, choice of components and materials etc, ... It's switched off by default on my motherboard, i'll switch it on and see if I can hear a difference.

[mansr]

Spread spectrum clocking is a method of reducing the peak radiated power by spreading the energy over a range of frequencies. It is independent of other methods such as shielding. Some interfaces support SSC, some do not. It is important to realise that SSC is used on the physical link between devices. The bus interface connecting the controller to the rest of a chip runs on a different clock. Moreover, all these clocks are independent of the DAC clock. If a PCIe link operating at a fixed 5 GHz doesn't bother the DAC running at (typically) 24.576 MHz, why would varying the PCIe clock slightly be a problem? There is no phase relationship between the two in the first place.

[LTG2010]

44 minutes ago, mansr said:

Spread spectrum clocking is a method of reducing the peak radiated power by spreading the energy over a range of frequencies. It is independent of other methods such as shielding. Some interfaces support SSC, some do not. It is important to realise that SSC is used on the physical link between devices. The bus interface connecting the controller to the rest of a chip runs on a different clock. Moreover, all these clocks are independent of the DAC clock. If a PCIe link operating at a fixed 5 GHz doesn't bother the DAC running at (typically) 24.576 MHz, why would varying the PCIe clock slightly be a problem? There is no phase relationship between the two in the first place. 

The variations in the process clock frequency modulation can cause measurable jitter over 20ns according to some chipset manufacturers. The Jittered signal might explain the audible difference, unless you are of the opinion that jitter is dealt succesfully by the DACS buffers, then its not an explanation.

[vortecjr]

1 hour ago, mansr said:

Spread spectrum clocking is a method of reducing the peak radiated power by spreading the energy over a range of frequencies. It is independent of other methods such as shielding. Some interfaces support SSC, some do not. It is important to realise that SSC is used on the physical link between devices. The bus interface connecting the controller to the rest of a chip runs on a different clock. Moreover, all these clocks are independent of the DAC clock. If a PCIe link operating at a fixed 5 GHz doesn't bother the DAC running at (typically) 24.576 MHz, why would varying the PCIe clock slightly be a problem? There is no phase relationship between the two in the first place.

John S. has a hypothesis that oscillators can negatively  impact each other. Unfortunately, I don't think that his research is far enough along to comment on the exact mechanism. My contention has been since this is so hard to measure its impact most be very small. Understand that he is having to build very low noise hardware to even start the investigation. Having said that....it's probably not a good idea to add more noise:) 

[mansr]

2 minutes ago, LTG2010 said:

The variations in the process can cause measurable jitter over 20ns according to some chipset manufacturers.

Measured where?

[LTG2010]

32 minutes ago, mansr said:

Measured where?

https://www.microsemi.com/document-portal/doc_view/135439-white-paper-spread-spectrum-clocking

Here's a white paper from Microsemi, see page 3-5, on jitter and the conclusion, I think just the conclusion alone will make audiophiles switch SSC off. (And this is from a company selling SSC modulation products - It might be worse)

[mansr]

40 minutes ago, vortecjr said:

John S. has a hypothesis that oscillators can negatively impact each other.

We're not talking about adding or removing oscillators, only about slightly altering the frequency of some of them. Now I can imagine that with two oscillators close in frequency as well as in physical proximity, some kind of interference could result in jitter at the difference frequency. That is, however, not the case here. Most DACs have oscillators at 22.5792 MHz and 24.576 MHz while PCIe and USB3 data clocks are 5 GHz and up, more than 200 times higher. You might as well be worried about gamma rays from a nearby banana causing interference.

 

40 minutes ago, vortecjr said:

Unfortunately, I don't think that his research is far enough along to comment on the exact mechanism. My contention has been since this is so hard to measure its impact most be very small. Understand that he is having to build very low noise hardware to even start the investigation. Having said that....it's probably not a good idea to add more noise:) 

Why doesn't he borrow a university lab for a few hours? I'm sure it could be arranged.

[mansr]

10 minutes ago, LTG2010 said:

https://www.microsemi.com/document-portal/doc_view/135439-white-paper-spread-spectrum-clocking

Here's a white paper from Microsemi, see page 3-5, on jitter and the conclusion,

That 20 ns figure is taken from the PCIe spec, which clarifies that this is an accumulated value over 1 million unit intervals.

 

10 minutes ago, LTG2010 said:

I think just the conclusion alone will make audiophiles switch SSC off.

Only if they've misunderstood it.

[mansr]

Just to put some things in perspective, a full SSC sweep with triangle modulation at 30 kHz is shorter than one sample interval for CD audio.

[vortecjr]

46 minutes ago, mansr said:

We're not talking about adding or removing oscillators, only about slightly altering the frequency of some of them. Now I can imagine that with two oscillators close in frequency as well as in physical proximity, some kind of interference could result in jitter at the difference frequency. That is, however, not the case here. Most DACs have oscillators at 22.5792 MHz and 24.576 MHz while PCIe and USB3 data clocks are 5 GHz and up, more than 200 times higher. You might as well be worried about gamma rays from a nearby banana causing interference.

 

Why doesn't he borrow a university lab for a few hours? I'm sure it could be arranged.

I wasn't talking about adding or removing oscillators, but not having them would be nice if they are not needed for audio. John's hypothesis is related to oscillators that are higher noise impacting oscillators that are low noise. So in theory having more noise is bad. Again understanding the exact mechanism will require the research to move forward. Remember the CPU, USB, and ethernet related oscillators are within the range of the audio oscillators.

[LTG2010]

1 hour ago, mansr said:

Only if they've misunderstood it.

And therefore Larry should switch SSC back on even though he can hear a clear audible improvement with it off.

"Maximum peak to peak 4ns, 0.5% center spread, just over 20ns. This level of jitter is actually quite high................etc."

Without extra modulation no introduced jitter therefore best left off in audio.

[mansr]

2 minutes ago, LTG2010 said:

And therefore Larry should switch SSC back on

I'm not telling anyone what to do.