What input method should I choose between laptop and DAC?

I use the USB input to both my Bithead and m903, but I have read that the Optical sounds smoother because it has less noise in the signal path.  I could not get my Optical Out from my soundcard to properly feed my m903 so I never tested how it sounded.

Here is what Wes Philips said about USB vs TosLink on an m902B.

"Ditch the USB connection," he said tersely. A TosLink connector was at hand—and went in...Much better. The murk disappeared, and the bass was quite a bit more solid and seriouser"

--Wes Philips

Don't take that comment regarding USB to be a valid universal/blanket condemnation. Properly implemented, USB should be superior to SPDIF over coax or TOSLINK.

It depends on the particular DAC, the software setup, etc. etc. What DAC are you planning to drive from the laptop?

What kind of laptop do you have?

Mac Book Pros (from experience) have a toslink optical connection hidden within the headphone out jack...

IMHO, a usb and a optical connection are both good... I understand that Optical is supposed to be better (and I agree) however, the difference between the two would be pretty marginal I would imagine... If you use your laptop as a portable device, I think the USB connection will be more practical as it is more sturdy in construction compared to the optical port... I cannnot imagine my desktop optical conection be plugged and unplugged multiple times without it giving out at some point, whereas the USB connections are pretty good and these impromptu connect/disconnects (think USB drives)

Just a suggestion :)

Quote:

Originally Posted by Hzwwwc2 
Well looks like pretty much I'm screwed. my laptop doesn't have digital or optical output, only usb port  :(

Optical and USB (and coaxial) are digital (zeros & ones), so I can not see there being that much of a difference for transmitting digital audio.

Historically (meaning pre-computer audio days) TOSLINK was said to have more problems with jitter than SPDIF over coax, so most enthusiasts considered coax to be superior.

However, computers being a noisy environment from the standpoint of electrical noise...being that they are not designed to be audio components...TOSLINK might well be superior to a coax connection from a particularly noisy PC.

I've used an E-MU 0404USB quite happily over USB for 5 years now, but it was one of the first devices to use proprietary drivers and thus operate more or less as an outboard data storage unit. It takes in the data and reclocks it to the d/a section independently of timing on the USB connection, which is how the original USB Audio standard works.

The only problems I have run into are with my laptop when it's running on AC adapter. Laptop adapters use a switching power supply that can create a lot of electrical noise on the laptop power ground, which can transfer through the machine to the USB port ground...and if a USB DAC's analog output section ground is not effectively isolated from the USB input ground, there can be problems.

If I use the 0404USB's internal headamp, I don't ever have a noise problem. If I use a separate headamp connected to the line outputs of the 0404USB, I hear a variety of hiss, static, and "beeping-like" noise when the AC adapter is plugged into the laptop.

With a Musical Fidelity VDACii, I heard the noise all the time when the AC adapter was plugged into the laptop, no noise when disconnected as the only way to use it is with the analog outputs connected to the external headamp.

With an Audinst HUD-mx1, the results were the same as with the 0404USB...noise on an external headamp connected to the analog output jacks only when the AC adapter was connected to the laptop, but no noise when disconnected, and never any noise with headphones connected to the Audinst internal headamp jacks.

To me...all this means is that some USB DAC's are improperly designed, as it's clear the headphone outputs can be adequately isolated, and there's no reason the line outputs should suffer from noise problems.

Some laptops won't have noise issues and will work well with a variety of DAC's over USB. So all things considered, you have to use what works best in your own situation.

Quote:

Originally Posted by Hzwwwc2 
I use my laptop as a source and my friend gave me some advice on the input method, I'm totally confused.

I thought all the input methods are the same, or if anything is better, usb input will be since it's more digital? (I know that I don't know anything...)

so could anyone teach me the different input methods, and which are better for a laptop?

Your laptop comes with a built in DAC (Digital to Analog Converter), it would be a cheap DAC, just enough to do a decent job.

Your can hook up a better quality (external) DAC (then what comes in the laptop) to the USB port.

You can also get a better (external) headphone amplifier, then what comes built into the laptop.

You could hook a external headphone amplifier to the line out on the Laptop, using the laptops DAC.

Or hook up the external headphone amplifier to an external DAC (better).

Or get an external (all in one) USB/DAC/Headphone amplifier.

I had a quick look at the specs for the NFB10SE..

http://www.audio-gd.com/Pro/Headphoneamp/NFB-10.1/NFB10.1EN.htm

Seems like USB supports 24/96 only, whereas there is 24/192 for coaxial/optical

I am in the same situation with my DAC, hence the reason why I use optical...

Something to think about

Maybe more experienced members can contribute and provide advice...

Quote:

Originally Posted by Jaywalk3r 


According to Universal Serial Bus Cables and Connectors Class Document Revision 2.0 (page 6), the standard USB A plug is designed to withstand ~1500 insertion/removal cycles. I could not find information on the durability of TRS plugs.

Best I could find for optical(fibre optic), it is wikipedia though.. so content of the article is questionable...

http://en.wikipedia.org/wiki/Optical_fiber_connector

Under applications, 500-1000 connection cycles...

Just my opinion, YMMV

Use USB with the NFB-10SE and don't worry about it so much. 

 Purpleangel: An S/PDIF digital audio signal, unlike transmissions inside a computer, is dependent on the accuracy of the timing, so "it is just ones and zeros" doesn't give the complete picture. 

Toslink is a terrible connection method. On a 'scope, the signal should look like a perfect square wave, but on the other end of a Toslink connection, it certainly does not. USB has its share of issues too though, mainly from the computer.