USB optical cable : stunning IF powered & implemented correctly

[Qhwoeprktiyns]

Hi,

 

When you say "USB optical cable enables a new hifi paradigm", what exactly have you compared this to in order to reach that conclusion ?

 

thanks

[Qhwoeprktiyns]

12 hours ago, tgb said:

Hi Hopkins,

I pointed out "new paradigm" because you can have a nice SQ with a do-everything PC as a source. A dedicated audio server becomes useless.

My background :

- tested NAS as music server (LPS on NAS > optical network to renderer) : worse

- I moved from NAS to audio server (NUC / fanless / LPS ; Win10 with optimized processes or Daphile as OS) : worse.

 

Cost of optical cable + LT3045 based PS = 350Eur

Standard PC as a source = no extra-cost / versatility / multimédia source

Then, see signature, I put some cash in the USB-spdif interface.

Optical cable + optimized interface => here is the good SQ.

This way : you "hear" the cash you spent.

 

I'm not saying that the current trend to build an audio server is useless.

I'm saying :

- it's expensive

- technically it is not "smart" in a sense that it's way more efficient & cheaper to clean the noise of a basic PC than building an audio server that generate a very low noise. Technically not smart because the noise is not "encrypted" in the data stream. Thus, optical isolation & reclocking (fine reclocking) after any basic server is fine enough to create a clean spdif stream.

- optical usb cable is an exemple , Grimm MU1 & Innuos Phoenix are other examples that show that "good cleaning" after a server can be dead efficient, much more cost efficient than building a dead silent audio server.

Rgds

 

To call this a new "hifi paradigm" seems to me exaggerated, and unsubstantiated. 

 

Unfortunately, your tests will never let you realize this because you are only focusing on one aspect of the digital chain: the quality of the USB signal. There is a lot more going on after: conversion of the USB to spdif (in your case), then handling of the spdif signal in the DAC. 

 

Simply "tweaking" a Singxer to put in better power and clocks is unfortunately not sufficient. An XMOS chip will itself generate a lot of noise, irrespective of how clean the power you supply it with. This noise will spread, disrupt the clocks, etc... 

 

[Qhwoeprktiyns]

What you don't seem to understand is that irrespective of its power supply, computer components (processors, like the XMOS) generate noise! In other words, the noise does not only come from power supplies. 

 

Imagine your refrigirator is making a lot of noise, and you call a repairman, who suggest installing a power filter to supply "cleaner" power... That makes just as little sense as trying to fix the problems of digital audio (which are quite complex) just by adressing it by tweaking power supplies! 

What you are doing may provide some very marginal benefits, but the effort involved is probably not worth it. 

 

Instead of wasting your time with this type of pointless tweaks, you should look into what serious/professional engineers are doing to address all these issues. 

 

However, good luck :) 

 

 

 

 

 

 

 

 

 

 

[Qhwoeprktiyns]

52 minutes ago, fds said:

If the computer is a laptop running on battery, I do not see how it will pollute the mains. Also I am not sure how much of the noise will travel down the USB cord, in particular, if this is made of fiber. What will remain though is some computer-caused jitter that will travel down the USB line towards the DAC. However, now with a good well-powered reclocker such as an IsoRegen on a good LPSU or a Phoenix, that jitter will be reduced significantly. Thus, I think @tgb has a very promising approach there ... In fact, I do find the term "new paradigm" quite suitable. 

 

Heads-up: its all been tried before...

[Qhwoeprktiyns]

33 minutes ago, tgb said:

Hi hopkins,

you're right... I should ask an engineer in electronics. But none around, thus I took the 1st engineer around, myself ;-) Not in electronics but in chemical engineering. That engineer knows a bit more in chemistry / ind. processes / fluids mechanics than electronics... but he was available right away thus I said to him  : go for it ! :-)

 

What else ? Anybody knows that. Nothing new there.

so, what next ? if I follow this remark, any DAC with an xmos chip is bad stuff (because this chip kills the SQ). Why not, but there are quite numerous DAC with xmos chips on the market , for years, and quite numerous people aere happy with the SQ

If there was a marginal benefit, I would not take time to post about a loosy tweak. No sense.

 

Thanks for the joke :-)

Honestly, are you sure we can call "serious engineer" (in electronics) that put a basic regulator to get 3.3V to power a clock ?

A clock !!!!???

That's (maybe) the most important component in any digital device !

Rgds

 

Yes, unfortunately it seems that the XMOS chip does kill SQ if used as is. The noise it generates is measureable, and you may find it surprising, but some engineers (not chemical engineers) have actually measured it.  Moreover, outputting I2S signal from XMOS, with high bandwidth, just carries the noise downstream. You can put the best clock behind an XMOS, with the best power supply, it will not prevent noise from spreading from the xmos to the clock. 

 

Unfortunately digital audio cannot be solved by the type of amateurish endeavors you are pursuing... 

 

What is the remedy? You'll soon find out (though not by reading the "french forum") :) 

 

Until then, have fun with your tweaks! 

[Qhwoeprktiyns]

1 hour ago, tgb said:

In the meantime, I have a modded SU-1 that give a SQ that is miles away from the stock version

When I modd the PS on the xmos, SQ will improve. 

Fine with that.

 

Honestly, that's a bit strong to focus on xmos noise as the "SQ killer", given that no product on the market uses 1 or 2 steps linear regulation to power perfectly that chip... (I don't know about boxes >10k$... )

Rgds

 

I have really big doubts on the fact that SQ can significantly improve by simply changing the power supply on a chip. 

 

As I mentioned earlier, a chip, any chip, will produce noise, regardless of how clean the power supply is. It is exactly the same thing as believing that you can get high fidelity from a computer by simply changing the power supply. 

 

If you think you are getting phenomenal results by doing these things, fine, there is no harm in trying :) 

[Qhwoeprktiyns]

Lol, its a French invasion 😁