[Matrixnobu]

I recommend the usb over the optical. I lost a lot of the soundstaging with the optical. But as a warning I had to get another usb cable cause the one that came with the NFB-12 wasn't very good and I got some dropouts.

 

[anoxy]

Yeah, the only reason I've been using optical is for convenience sake, and because I'm running out of USB ports on my iMac. I need to get a usb hub or something. 

 

[Brooko]

Quote:

I recommend the usb over the optical. I lost a lot of the soundstaging with the optical. But as a warning I had to get another usb cable cause the one that came with the NFB-12 wasn't very good and I got some dropouts.

 
Funny - with the original NFB-12 my understanding is complete opposite.  I noticed no difference in sound-stage between optical and USB, but there is apparently some treble roll-off with USB (there was a thread here quite a few months ago where it was discussed and even measured).  Can't say I notice any difference either way - I compared the two a lot when I first got the unit, and couldn't tell the difference.
 
I think that's why Audio-gd worked on the NFB-15 (essentially an NFB-12 with upgraded USB).
 
Go with what you prefer (some people prefer rolled off treble) - but my preference definitely optical in this case - simply because I can then use DSPs from my X-Fi if I'm gaming. 

 

[Brooko]

Quote:

Yeah, the only reason I've been using optical is for convenience sake, and because I'm running out of USB ports on my iMac. I need to get a usb hub or something. 

 
You should actually try comparing the two - and see if you can actually tell the difference.  Could be enlightening.

 

[genclaymore]

With me I have to use a sound card with my NFB-12 Thur optical, or I get 50% volume when I got to play games. even tho the volume setting is maxed out in windows. Besides the TE7022 making the game stutter. I stil think the volume issue I have with games is a config issue on my end. Since I haven't seen some one mention that games output 50% volume from theirs NFB-12 usb connection. I don't know if it has something to do with the game using the windows sound mixer, or something else.  Interesting enough It doesn't happen when I using a music program even while using Wave out.
 
I would love to be able to use the USB TE7702  without using a sound card as a Digital transport for gaming if it would just output at 100% volume gaming and not 50%, so I can remove that DG out and have room for Crossfire. Yea I'd use my VIA onboard Spdif out if that wasn't full of similar audio glitch.

 

[Matrixnobu]

That's interesting. Are you using an aftermarket optical cable? I tried the one that came with the unit.
 
 
Quote:

 
Funny - with the original NFB-12 my understanding is complete opposite.  I noticed no difference in sound-stage between optical and USB, but there is apparently some treble roll-off with USB (there was a thread here quite a few months ago where it was discussed and even measured).  Can't say I notice any difference either way - I compared the two a lot when I first got the unit, and couldn't tell the difference.
 
I think that's why Audio-gd worked on the NFB-15 (essentially an NFB-12 with upgraded USB).
 
Go with what you prefer (some people prefer rolled off treble) - but my preference definitely optical in this case - simply because I can then use DSPs from my X-Fi if I'm gaming. 

 

[Brooko]

Quote:

That's interesting. Are you using an aftermarket optical cable? I tried the one that came with the unit.

 
Yep - that's the same cable I'm using.

 

[knwtmsyn]

Could someone please explain to me what the OS and FILTER switches do? Is there any way to get a neutral output from this thing?
 

 

[Matrixnobu]

The OS changes the way the DA outputs the audio wave. Supposedly the higher the Oversampling the smoother the waveform.
 
The filter switch gives you an option of differing lowpass filters. All DA's have lowpass filters to get rid of digital noise. This one just gives you the option of different ones.
 
It's best to try different one's and see what sounds best to you. I'm using 2x oversampling Linear phase softknee filter right now with my Sennheiser HD-545's.
Quote:

Could someone please explain to me what the OS and FILTER switches do? Is there any way to get a neutral output from this thing?
 

 

[knwtmsyn]

I have no right to complain about more options! Thanks for the response.

 

[KimLaroux]

Audio-gd posted frequency response graphs of the different settings on their website:
 
http://www.audio-gd.com/Pro/Headphoneamp/NFB12/NFB12EN_Specs.htm
 
For me the most obvious difference between the filters is the degree of treble roll-off. All the 2X OS settings have early roll-off. The 8X OS are essentially flat within audible range. With 4X OS, you have the choice. I use the Linear phase "Brickwall" filter simply because it's the 4X OS filter with the best treble extension.
 
The difference between minimum phase and linear phase has to do with how the pre-ringing and post-ringing are filtered. See this.
 
I've been meaning to add switches to my NDB-12 so I can more easily compare the filters... but I still haven't figured a clean way to mount the switches. Just thinking about machining such big holes into the enclosure makes me uncomfortable.
 
These days i just leave the cover unscrewed, so that I can still change the filters without tools. Besides the treble extension, I really can't tell what else is different, even if it seems obvious from the paper I posted. I just wish I knew which one was objectively the best, the one that more precisely reproduces the original analog signal. My guess would be 8X OS, Minimum phase apodizing filter. Sad it's limited to 48Khz input though.

 

[genclaymore]

I tend to use 4x Minimum Phase Soft knee filter my self, some times i try 8x  Minimum phase apodizing but usually switch back.

 

[anoxy]

Could somebody point me to an explanation of all this "linear soft knee minimum phase brickwall" jargon? And also how each term corresponds to the switches on the front of my 12.1?

 

[Brooko]

Quote:

Could somebody point me to an explanation of all this "linear soft knee minimum phase brickwall" jargon? And also how each term corresponds to the switches on the front of my 12.1?

 
http://www.audio-gd.com/Pro/Headphoneamp/NFB12/NFB12EN_Specs.htm

 

[anoxy]

I can't believe I missed that. Thanks for the link.
 
So it looks like I have it set to 8x oversampling, linear apodising filter.