Topic: converting usb to toslink

[qguy]

i have heard that converting a usb output  to a toslink improves the sound,  how does this work since the source is usb from the start ?

[comgen]

yung isang way na ma convert yung USB to toslink is
using an external sound card like the Encore - ENMAB8CM sold @ CDR King.
first the signal is passed to the sound card(S.C.) through the usb,
next the S.C. processes the signal
finally the S.C. outputs the signal to the TosLink Port

so kung maganda yung External Sound Card Mo na nakakabit via the USB, me possibility na gaganda nga yung sound.   

[Stagea]

i have heard that converting a usb output  to a toslink improves the sound,  how does this work since the source is usb from the start ?

If the USB to SPDIF interface runs its own clock (which is the trend nowadays) and if that clock is of a good quality, then the timing of the output signal would likely be more consistent / would exhibit lower jitter.

[Courage]

If my laptop has HDMI...

anong mas maganda?

Use USB converted to Toslink - to Amp

or

HDMI - Amp

Lets say just for audio application

[Stagea]

If my laptop has HDMI...

anong mas maganda?

Use USB converted to Toslink - to Amp

or

HDMI - Amp

Lets say just for audio application

Granted that the Toslink implementation can reliably accomodate the stream that you're sending, Toslink.

HDMI is a high jitter interface, as it wasn't a ground up design for Video and Audio from the beginning. It's primarily a video interface (based off DVI-D) with audio being an afterthought (the audio stream is MUXed into the rest of the packets being sent, then DEMUXed on the receiving end before decoding). It's a pretty shoddy approach if the data is to be played in real-time (unless some extra buffering is applied).

A good Toslink implementation should offer lower levels of interface jitter. Galvanic isolation is also a plus.

[Courage]

Granted that the Toslink implementation can reliably accomodate the stream that you're sending, Toslink.

HDMI is a high jitter interface, as it wasn't a ground up design for Video and Audio from the beginning. It's primarily a video interface (based off DVI-D) with audio being an afterthought (the audio stream is MUXed into the rest of the packets being sent, then DEMUXed on the receiving end before decoding). It's a pretty shoddy approach if the data is to be played in real-time (unless some extra buffering is applied).

A good Toslink implementation should offer lower levels of interface jitter. Galvanic isolation is also a plus.

Thanks for the explanation sir.. Although i don't know what Galvanic isolation is

[markcrenz]

Granted that the Toslink implementation can reliably accomodate the stream that you're sending, Toslink.

HDMI is a high jitter interface, as it wasn't a ground up design for Video and Audio from the beginning. It's primarily a video interface (based off DVI-D) with audio being an afterthought (the audio stream is MUXed into the rest of the packets being sent, then DEMUXed on the receiving end before decoding). It's a pretty shoddy approach if the data is to be played in real-time (unless some extra buffering is applied).

A good Toslink implementation should offer lower levels of interface jitter. Galvanic isolation is also a plus.

so potentially optical or coax is better than hdmi for digital audio?

[Stagea]

so potentially optical or coax is better than hdmi for digital audio?

With the audio stream being the same, yes.

[Courage]

With the audio stream being the same, yes.

Let say i have an NMT with both HDMI and Toslink or even COAX..

It's possible that Audio quality is much better if i use the Toslink interface instead of HDMI?.. Let say content being played is Audio only..

[Stagea]

It's possible that Audio quality is much better if i use the Toslink interface instead of HDMI?.. Let say content being played is Audio only..

It's entirely possible, and perhaps even likely. The difference may not be "much" in most cases (because you said much better), but it's probably noticeable.

Of course, the implementation of the Toslink or Coax SPDIF output also matters (dedicated media players tend to have poor ones). A poor implementation of a sound design may not end up as good. Some receivers may also have poor quality spdif inputs, which may put them at a disadvantage (or the HDMI implementation may be excellent in certain devices).

As with anything, ymmv.

This is like a sedan vs. a sports car. The sedan is more versatile (HDMI) but typically does not perform as well as the sports car (SPDIF). Despite this, a good sedan may perform better than a bad sports car, however.

[qguy]

Is the specs for the clock indicated on the spec sheet for the DAC and Converter ? normally i just see a XX bit / XXX mhz specs, what should I be looking at when looking for a USB to SPDIF converter ?

If the USB to SPDIF interface runs its own clock (which is the trend nowadays) and if that clock is of a good quality, then the timing of the output signal would likely be more consistent / would exhibit lower jitter.

[Stagea]

Is the specs for the clock indicated on the spec sheet for the DAC and Converter ? normally i just see a XX bit / XXX mhz specs, what should I be looking at when looking for a USB to SPDIF converter ?

Makers normally would not indicate how accurate their clocking is. Jitter measurements (both RJ and DJ) together with oscilloscope waveform plots are what you'd need to evaluate the performance of an interface.

Devices that run asynchronous to the USB bus is normally a good place to start (though there are adaptive devices that do well too), and having 2 clocks for different frequency multiples (or a precise algorithm from a single clock) is normally preferable.

Depending on your DAC, an interface that does not stop streaming when there is no signal input may be helpful too (to prevent sync delays and noises).