Audio-GD NFB-12
Jan 4, 2012 at 7:08 AM Post #1,681 of 2,280


Quote:
My NFB-12 was of the old stock (the first batch.)
It has no filter selection so only default brick wall filter.
But I always wondered about the "dimness" all man keep mentioning about, because I felt nothing of the sort.
 
Indeed, NFB-12 has a roll off beginning from 8kHz to 20kHz, due to the filter setting.
But it's only 6dB even at the lowest point.
Can you imagining how small that is?
I got a recording interface recently (RME Babyface, very good recording equipment if you know it.)
Added with a condenser microphone, I was able to to some headphone FR test.
Here's two example:
 
Beyerdynamic T1 with Babyface's Headphone out:
 
74a70597e6ecbeee84ecf07a8c06b63f.jpg

 
Here's with NFB-12:
 
9d47d0a702f4430351b6067a575704d7.jpg

 
I can't really see any difference in the high FR difference that was resulting from the small 6dB roll off of the filter setting.....
 
 
So it really is not a big issue with me.
 
BUT, 
the USB input is very problematic!!
I don't know what Audio-GD had done wrong, but their TE7022 receiver part is not setup correctly!
What ever computer I used and what ever systems, software I've tried, the thing would no get correct 24/96 kHz sample data
It would ACCEPT such input from USB, but somehow distort or resample it so only below 44kHz in really into the DAC.
So it got terrible distortion with high res data, (16bits/44kHz is all right)
It's fine when I switched to optical feeding from the babyface, no fake resample at all.
So the USB receiver is not really working with 24bits/96kHz high res but only working properly with 44kHz data.
 
The computer I tried including PC, notebook, MAC. Software with ASIO4ALL under windows XP, WASPI under Windows 7.
All to the same result.
 
THAT's not proper.......
 They should fix it really......



Best headphone amp post I've seen in months,  blows away all the meanlingless meter readings over at that blog about oxygen.  Really puts things in perspective.  Thanks.
 
 
Also read a few pages back,  you should can be upsamplin with sox using that 2x filter,  then the 6db dip gets pushed into the ultrasonic region.
 
Jan 4, 2012 at 4:14 PM Post #1,683 of 2,280
For MAC users I found this:
 
Recommended Player Settings for Optimal Audio Quality
 
[edit]
Set the correct sample-rate and set word-length to 24 bit
These are set in the 'Audio MIDI Setup' control interface, which is in the 'Utilities' folder:
(Applications -> Utilities -> Audio MIDI Setup).  
 
 
http://extra.benchmarkmedia.com/wiki/index.php/ITunes-QuickTime_for_Mac_-_Setup_Guide
 
Jan 7, 2012 at 8:58 PM Post #1,684 of 2,280
Finally got to compare the e9 and -12.  It's actually pretty close for me but I the -12 was an easy choice.  I used the line out of the -12 to feed the e9 so they were both using the same DAC and same interconnects. I like the bright sound of my grado's but the warmer -12 was a better match and it seemed to have slightly better sound stage.
 
On a side note though, the e9 was my first amp and I haven't listened to it since I got my 2nd amp (I'm now on my 5th or 6th) and I'm really surprised by how good it sounds.  It is not my best sounding amp or one of my best sounding amps but it is still a solid amp (and so if the -12 obviously) and I would happily listen to it.  I always did think it was the e7 that held the e9 back.
 
Jan 9, 2012 at 3:42 PM Post #1,685 of 2,280
Pretty off topic but..
2011-12-27  01:41:00  GUANGZHOU  Dispatch from Sorting Center  
Still haven't received it, I actually had a dream about this dac few nights ago, weird. 
Hopefully it will come this week
beyersmile.png

 
Jan 9, 2012 at 3:57 PM Post #1,686 of 2,280
What did you pick for shipping, EMS or DHL?
 
Jan 9, 2012 at 4:04 PM Post #1,687 of 2,280
Pretty off topic but..
2011-12-27  01:41:00  GUANGZHOU  Dispatch from Sorting Center  
Still haven't received it, I actually had a dream about this dac few nights ago, weird. 
Hopefully it will come this week
beyersmile.png

I've had dreams over a Stax rig some time ago, it seems only natural around these parts, lol.

 
Jan 9, 2012 at 10:21 PM Post #1,688 of 2,280
Received my NFB12 this morning. Got nothing to complain about except the too bright blue led lol.
Shipping is very fast (3 days EMS). I got charged ~$30 for import tax and VAT (Customs decided that my package worths $100 instead of the $50 declared value)
 
 
Anyone know how long can you leave this DAC on? 
I heard it needs ~100 hours burn-in but I don't wanna damage the unit in the process.
 
Jan 10, 2012 at 2:07 AM Post #1,690 of 2,280
Didn't really pick, they sent it with EMS, I would've chosen DHL though.
Oh well, it'll probably come this week.
 
Also, which would be better: The amp in NFB-12 or Little dot MK I+?
 
Weird combination though, not sure if anyone has tried.

The NFB-12 is most likely better, but probably not by a large amount.
In any case it doesn't warrant buying both. If you want a better amp look to spend around $200-300.
 
Jan 10, 2012 at 3:24 AM Post #1,691 of 2,280


Quote:
Didn't really pick, they sent it with EMS, I would've chosen DHL though.
Oh well, it'll probably come this week.
 
Also, which would be better: The amp in NFB-12 or Little dot MK I+?
 
Weird combination though, not sure if anyone has tried.


Amp in NFB-12 must be better, because not contains any opamp or feedback. 
http://lh6.ggpht.com/_RRoLRBPyKiw/SPtB45f3BAI/AAAAAAAAAgI/pFJPVzgQ1Nc/Little%20Dot%20MK%20I%2B%20Circuit.jpg
vs
http://www.audio-gd.com/Pro/Headphoneamp/NFB12/NFB124.jpg
 
 
Jan 10, 2012 at 3:42 AM Post #1,692 of 2,280
Amp in NFB-12 must be better, because not contains any opamp or feedback. 
http://lh6.ggpht.com/_RRoLRBPyKiw/SPtB45f3BAI/AAAAAAAAAgI/pFJPVzgQ1Nc/Little%20Dot%20MK%20I%2B%20Circuit.jpg
vs
http://www.audio-gd.com/Pro/Headphoneamp/NFB12/NFB124.jpg
 

Generally speaking opamps actually provide better performance than discrete circuits. And besides, both amplifiers do not contain any opamps, as far as I know.
The only advantage of using transistors over opamps is that they are more suited for high power applications, and provide more control on the designers end.

The main reason why I would say that the NFB-12 is better is because of the fact that the Little Dot I+ uses very simple circuitry and small amount of parts. Most likely the largest cost in that amplifier are the chassis and tubes, leaving little money left over for other parts at $100.
Also the NFB-12 has a better power supply as well.

The advantage of the I+ is probably the support of tube rolling allow the user to slightly change around the sound signature.
 
Jan 11, 2012 at 12:27 PM Post #1,694 of 2,280
Audio-GD's website now lists NFB-12 and NFB-12.1.  Not sure what the differences are, anyone know?  The information page hasn't been updated.
 

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