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

[mansr]

Could it be that eliminating switches or other hardware restores absolute polarity of the audio signal?

 

No, that's impossible. All networking equipment transfers the signal unchanged. Nothing would work if it didn't. The worst a switch can do is inject analogue noise riding on the digital signal. Flipping the polarity of an audio stream is as impossible as the switch translating English text to Russian as it passes through.

[mansr]

2 hours ago, marce said:

Being closer you can use a weaker drive strength for the the signal, slower rise times, again limiting the amount of energy in a circuit and thus again reducing noise and other coupling mechanisms

In many SoCs, drive strength and other parameters are configurable for each pin or group of pins.

[mansr]

8 minutes ago, beerandmusic said:

In the mean time, i just picked up a sr5012 that can function  as a gapless DSD player dac....may not be the same fidelity I want, but it will have to satisfy until the right piece of gear comes along.

It can even convert DSD to PCM and send it through Audyssey room correction.

[mansr]

46 minutes ago, BigGuy said:

Either that or the novel is a reference to long books like War & Peace!  ;-)

Didn't you know placing a large book on top of the DAC alters the sound according to the genre. Matching the book to the music gives the best results.

[mansr]

Make sure you're not using a 2.5 mm plug with a 2.1 mm jack. That tends to give an unreliable connection.

[mansr]

39 minutes ago, sandyk said:

 Don't you just love the mish mash of this type of D.C.plug and socket, where you may need to physically try a pair together ?  The vendors often don't appear to have clear compatibility labelling or adequate descriptions.

The worst is that odd bit of kit that wants centre cold. That's the very definition of insanity.

 

39 minutes ago, sandyk said:

The problem that I was having was with correct matching pairs, supplied as pairs.

That sucks.

[mansr]

49 minutes ago, ElviaCaprice said:

A clean 12V to the mobo  would be a clean 12V to the CPU.

Modern CPUs run on around 1 V. Peripherals are typically 1.8 V or 3.3 V. There is typically a switching regulator near each high power consumer, often combined with LDO regulators for fine control.

[mansr]

46 minutes ago, Speedskater said:

That seems highly unlikely. It also seems unlikely that fuses from different brands that have the same characteristics will have a significant difference in resistance.

I checked a few 13 A fuses I happened to have lying around. All were around 5 mΩ, though it's hard to get an accurate reading due to contact resistance. A 3 A fuse I checked was about 45 mΩ. A power cord is probably around 100 mΩ. I don't see how the fuse could possibly make a difference.

[mansr]

54 minutes ago, marce said:

I'm still getting my head around fuses with beeswax in them, this hobby reaches a new low... Putting something flammable in a safety device that generates heat!!! They should be banned... Audiophile fuses in general are just a step to far but the Audio Magic fuses just take it to a new low.

I doubt they'd be approved by any electrical safety agency.

[mansr]

2 minutes ago, sandyk said:

 That is not my experience with my own DIY amplifiers, and is why I use no fuses in the secondary side of the PSU.

 The boutique fuses often appear to have different combinations of metals in their formulation.

 N.B. I am not supporting the case for boutique fuses, just suggesting that the resistance of the fuse and it's holder may play some part in these reported observations by others.

If a resistance of a few mΩ makes a difference, something is horribly broken.

[mansr]

1 hour ago, RickyV said:

It is not in the resistance of the fuse but more in dampening the fuse wire. And maybe there is ferrite dust in there instead sand. I don’t know but do not focus on something that is obvious not it.

Ferrite would give it a slightly higher inductance. If high-frequency noise is an issue, it should be addressed with a purpose-built choke without the size constraints of a fuse.

 

1 hour ago, RickyV said:

I am not a fuse guy, i bought 3 audio fuses ones and didn’t do much. It is the obvious dismissal i do not like, think further what it could be. And some audio stuf is just simply bonkers, you should know that by now.

Oh, I know that. I dismiss magic fuses because I know that anything they could possibly do should have no effect whatsoever on competently designed gear.

[mansr]

1 minute ago, Speedskater said:

The 13A value looks correct. While the 3A value may be a little high, the spec sheet i just look at had it at 25mΩ.

Do you have a 4 terminal Ohm meter?  Or do you have enough other meters to DIY one?

I first used a Fluke 289 subtracting the test lead resistance. To double-check, I then ran 2 A, as measured by my bench supply, through it while measuring the voltage with the Fluke.

[mansr]

4 minutes ago, Johnseye said:

So formulated for gold or not, it doesn't really matter?

It won't be worse on gold than on something else. If anything, gold is easier to clean since it is non-reactive. Other metals can develop layers of oxide or other compounds that are much harder to remove than a bit of accumulated filth. There's also no risk of the gold being damaged by an aggressive cleaning product.

[mansr]

On 08/02/2018 at 9:56 PM, Speedskater said:

The 13A value looks correct. While the 3A value may be a little high, the spec sheet i just look at had it at 25mΩ.

Do you have a 4 terminal Ohm meter?  Or do you have enough other meters to DIY one?

I rounded up some more fuses. The 3 A ones consistently measured 45-50 mΩ. A 5 A fuse gave a reading of 25 mΩ. These were all BS1362 type, most of them Bussmann.

 

What spec sheet did you look at?

[mansr]

33 minutes ago, jabbr said:

I’m still having a big ??‍♂️ moment here ... how long is it going to take for everyone here to turn off spread spectrum and then repeat this thread ... ?

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

[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.

[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.

[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.

[mansr]

2 minutes ago, LTG2010 said:

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

Measured where?

[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.

[mansr]

2 minutes ago, LTG2010 said:

And therefore Larry should switch SSC back on

I'm not telling anyone what to do.

[mansr]

I'm just offering some facts about what these things actually do. What you do with them is up to you.

[mansr]

20 minutes ago, jabbr said:

See here's the thing: adding spread spectrum by definition adds waaaaayyyy more than 20ns jitter, so it totally swamps variations in logic process (very real) as well as clock oscillator.

Uh, could you clarify that a bit? For PCIe and USB3, we're talking about modulating the unit interval by 1 ps or less. Where are you getting 20 ns?