USB cable comparisons

[OldBigEars]

On 3/6/2020 at 8:10 AM, manueljenkin said:

USPCB arrived today. This cable is wicked fast. I'm hearing buffer overflow issues. Much more transparent and harshness free than supra, but detail depends on how the source functions. Now I'm 100% sure packet loss need not be super audible pops and clicks. It can be subtle and graceful.

 

I'm running a surface book, and I use wtfplay OS for my music playback. Here are my observations

 

Started off feeling that something was truncated off and dark with the typical 16 bit 44.1khz Redbook flac material. Changed buffer from the default 2048 x 2 to 1024 x 2 and it worked much better.

 

Then I played "purple rain" (a higher resolution recording). Huge buffer overrun in the default 2048 x 2. It was literally stuttering. Purple rain started playing fine after changing buffer to 64 * 8. Later I realized this overrun is so audible only because of the period count =2. Changed it to 4, with default period size of 2048 frames and it played without super audible stutter.

 

Also heard minor aberrations in other songs with default settings. "Mausam and escape", in Redbook cd format, there's a quick series of drum hits at the left side around 1 minute mark. It sounded quantized. Like I can hear the sample pulses (part of what makes the full sound) instead of the reconstructed sound.

 

Went to my computer uefi, disabled simultaneous multithreading. Purple rain played fine with default settings. But I didn't like the sound in this settings. Sounded too smoothed off.

 

Thought I was screwed. Realized I have one more control. Changed system priority from 50 to 30 in the command line, no changes to buffer. Everything else fixed, and no system tweaks as well (hyperthreading enabled again). Sounds fantastic, still got scope to tweak. Funky thing doesn't have a sound of its own (unlike the other cables I've tried that impart a specific character). The cable is super fast, I could probably tweak it to do anything which is a nice thing. But it's also sensitive and can show flaws without masking. I doubt there is any burn in period, but feel free to let me know of the designer officially confirmed any such thing.

 

 

I also use one of these USPCB connection devices.  I've never reached a conclusion as to whether or not it actually improves or degrades the sound on my system vs a stock cord.  I just use it for space saving, neatness and low cost (compared with a fancy cable).  I've never been able to move the tiny, little switch that apparently turns the VBUS on/off.  I can't even tell for sure what position it's in.  Does that matter and why would anyone want to turn it on/off?

[OldBigEars]

11 minutes ago, Superdad said:

 

Regarding the VBUS switch on UpTone USPCB A>B Adapters:

It should stay in the ON position (that is the downward position of the tiny white switch—where it then forms a line with the two white painted dots on either side).  

 

It is a bit of a joke—and really only useful for use in determining if you DAC needs VBUS.  If it does, then you leave the switch on; If it does not use VBUS then well, what’s the point of tuning it off?  It is not like the 5V goes anywhere.  You are not even keeping it off a long USB cable (some people like that to reduce capacitive coupling to the data lines). 

Useful as horns on a bull (at least for us)! 

 

That said, if you are able to hear differences between USB cables, then our USPCB Adapter should sure make a nice difference for you. It is a 4-layer impedance-controlled circuit board--designed to preserve the exact signal integrity of whatever you are feeding through it. In other words, unlike all USB cables (which modify SI--that's why you can hear character differences!), a high-speed USB eye-pattern put through a USPCB Adapter will look virtually identical.

There is no cable like no cable; and the USPCB Adapter is not a cable... 

 

Alex - do you happen to know if a Chord Qutest needs VBUS?

[OldBigEars]

On 6/27/2020 at 1:51 PM, manueljenkin said:

It connects/disconnects the 5v line from your pc usb port to your dac. If your dac has external power supply, keep the button off, else keep it on.

thats interesting. Sounds like it should turn off.  I’ve tried to move the switch but it’s not an easy task, at least on mine.