[kishorfarm]

Currently I use an HiFiman HE-500 driven by an EHP-O2 (O2+ODAC). The HE-500 is an awesome/crisp/highly detailed headphone but I would like to improve the amp/DAC part. My budget is not that big (max. 400€) but I don't mind buying second hand.
 
I've found the Audio GD NFB-11 to be an interesting DAC/amp and I've read many positive opinions and reviews.
 
The key question is: Will the Audio GD NFB-11 drive my HE-500 much better than my current O2+ODAC? Will the NFB-11 improve the resulting sound quality substantially?. I mostly hear metal, alternative and rock.
 
If not I can wait to increase my budget in order to buy a clearly better DAC/amp.
 
Thanks in advance and greetings from the south of Spain.
 
Alvaro

 

[cel4145]

First, keep in mind that with DAC and amps, when people describe upgrades as being big or significant, that's such a relative term compared to one's expectations. Some people will feel a 1% SQ improvement a big improvement, and what does that even mean, a 1% SQ improvement? How much is that to you vs. someone else? It's just really problematic to take one person's experience and relate it to your own once you get up to this quality of equipment. With the ODAC and O2, I think you have already reached such a high level of accuracy and transparency, I don't think you should expect significant SQ gains there from any ODAC upgrade and maybe not from an O2 upgrade.

My upgrades have been O2+ODAC->ODAC + Asgard 2-> NFB-11. With the ODAC vs NFB-11's DAC, I would describe the NFB-11 as a bit better; some others have described it as the same as the ODAC to them.

The headphone amp in the NFB-11? Sure, you will get a lot more power:

NFB-11
3500mW/25 ohm
1800mW/50 ohm
So guess somewhere in between for the HE-400's impedance.

O2
33 Ohms 613 mW

As far as overall SQ difference in the NFB-11 headphone output vs. O2? Unless you are pushing the O2 near its max output limits, I don't think you should expect to get big gains. With more power, you should get increased SQ from the better dynamics possible with the more powerful amp when pushed to higher volumes. In this regard, I have really enjoyed the NFB-11 with my HE-400s and AKG K612 Pros.

I also really do love the better ergonomics of the NFB-11 with it's front panel switch setup and full sized jack. I also think the pre-amp capability makes it a worthwhile upgrade should you want to hook up a tube amp, powered speakers, etc.

 

[kishorfarm]

Thank u very much for your answer cel4145, I didn't notice the e-mail notification regarding your answer until now. sorry.
 
I still didn't buy the NFB-11 but I will buy it within two weeks when coming back from holidays. I investigated a lot but didn't find a better price/quality DAC/amp combo.
 
As you correctly state, the O2 is driving the HE-500 with a high enough volume, but to do so the gain must be set almost to the limit (Gain ON and volume knob at 80%) so maybe distortion is already there. The NFB-11 will be working much more relaxed so I guess SQ should be better.
 
Anyway, when I buy the NFB-11 I will make a comparison with the O2/ODAC and publish the results here for public knowledge.
 
Thanks again for your feedback!
 
Greetings
 
Álvaro

 

[PurpleAngel]

  Thank u very much for your answer cel4145, I didn't notice the e-mail notification regarding your answer until now. sorry.
I still didn't buy the NFB-11 but I will buy it within two weeks when coming back from holidays. I investigated a lot but didn't find a better price/quality DAC/amp combo.
As you correctly state, the O2 is driving the HE-500 with a high enough volume, but to do so the gain must be set almost to the limit (Gain ON and volume knob at 80%) so maybe distortion is already there. The NFB-11 will be working much more relaxed so I guess SQ should be better.
Anyway, when I buy the NFB-11 I will make a comparison with the O2/ODAC and publish the results here for public knowledge.
Thanks again for your feedback!
Greetings
Álvaro

 
Whatever source(s) the ODAC/O2 is plugged into, hopefully your running the source's volume settings on high?
(like at 75% or greater).
I would guess that unless you have a need for the NFB-11's separate line-output or the S/PDIF (optical & coaxial) connection, just stay with the ODAC/O2

 

[kishorfarm]

   
Whatever source(s) the ODAC/O2 is plugged into, hopefully your running the source's volume settings on high?
(like at 75% or greater).
I would guess that unless you have a need for the NFB-11's separate line-output or the S/PDIF (optical & coaxial) connection, just stay with the ODAC/O2

 
Yes, sure. My source is a Lenovo Thinkpad. Windows 7 audio volume is always at maximum and foorbar2000 volume at around 75-95% (depending on the song).
 
Really? You think NFB-11 is not an upgrade over ODAC/O2?. I thought the increased power and the SABRE ES9018 DAC were going to be a noticeable improvement.
 
What would be, in your opinion, the minimum DAC/amp combo with a noticeable SQ improvement compared to the ODAC/O2 when driving the HE-500?.
 
Greetings.

 

[PurpleAngel]

   
Yes, sure. My source is a Lenovo Thinkpad. Windows 7 audio volume is always at maximum and foorbar2000 volume at around 75-95% (depending on the song).
 
Really? You think NFB-11 is not an upgrade over ODAC/O2?. I thought the increased power and the SABRE ES9018 DAC were going to be a noticeable improvement.
 
What would be, in your opinion, the minimum DAC/amp combo with a noticeable SQ improvement compared to the ODAC/O2 when driving the HE-500?.
 
Greetings.

 
Part of me was thinking you might have the source volume low, which might be a contributing factor for the low volume, but it is not the case.
I've thought of getting the NFB-11 myself, so I can't really say I have anything really against you getting the NFB-11.
But it's $400, I'm just trying to be careful and making sure the NFB-11 will be worth the $400 price, to you.
So buy the NFB-11 and sell off the ODAC/O2.

 

[cel4145]

As you correctly state, the O2 is driving the HE-500 with a high enough volume, but to do so the gain must be set almost to the limit (Gain ON and volume knob at 80%) so maybe distortion is already there. The NFB-11 will be working much more relaxed so I guess SQ should be better.

The HE-500s are only 89db sensitivity, which is very low for a headphone. If you are at 80% volume, and turning it up barely gives you any more volume, then you could easily be losing some dynamics where peaks on some music might be clipping the amp, or at least, nearing the limits where harmonic distortion tends to rise. Usually, I think its best to have at least an an extra 10db (if not 15db) of headroom on an amp, and it's certainly nice when that extra headroom is clean, not where the amp is reaching its limits.

 

[headphonatic]

You might want to try a speaker amp, you might like the synergy between the HE-500 and the TP60. I made switch from the O2 to the Topping TP60, and I can't hold a single thing from the O2 over the TP60. Make sure to buy attenuators

 

[kishorfarm]

I already bought the NFB-11 (2014). I'm happy with the purchase and I consider it as an upgrade from the O2/ODAC.
 
But there are annoyances:
 
(1) Surprisingly the NFB-11 does not deliver much more power than the O2. The output power specified by Audio GD (about 3000mw @ 32 Ω) is SPL-wise equivalent to the output power specified by O2 (640mw @ 32 Ω). I feel a little bit deceived and tricked with this as I was hoping much more power. Lukcily I don't need more, but when driving the Hifiman HE-500 I must set the volume knob at maximum in some songs (with the gain switch also set in high mode).
 
(2) Everytime I pause and play a song, a relay sounds. This causes a continuous 'clic', 'clic', 'clic', when I'm pausing and playing. Also when pressing play after a pause, along with the annoying 'clics', 0.5 seconds of music are lost until the relay allows the sound signal pass again. I hate this behaviour.
 
Kingwa already gave me a solution for (2). I must open the equipment and cut a cable to disable the relay. One day I will do so, and I thank Kingwa for the solution, but opening and cutting cables is not what I expect from a brand new product.
 
All in all is a good product with a good price, and apart from the power constraints, sound quality is very good, delivering a more natural and detailed sound than the O2/ODAC.
 
Greetings.

 

[manbear]

 
 
(1) Surprisingly the NFB-11 does not deliver much more power than the O2. The output power specified by Audio GD (about 3000mw @ 32 Ω) is SPL-wise equivalent to the output power specified by O2 (640mw @ 32 Ω). I feel a little bit deceived and tricked with this as I was hoping much more power. Lukcily I don't need more, but when driving the Hifiman HE-500 I must set the volume knob at maximum in some songs (with the gain switch also set in high mode).
 

Interesting. 

Volume is a function of voltage, so it seems the two amps have about the same peak voltage and the Audio GD is just capable of putting out more current. 

 

[Gloomy Moonie]

Hey kishorfarm /img/forum/go_quote.gif,
I'm looking at buying the NFB-11 as well, as it appears to be the best value option out there, though the issues you've described are a bit discouraging.
Has anything changed in the past two months regarding the software? Or do the issues persist?

 

[kishorfarm]

  Hey kishorfarm /img/forum/go_quote.gif,
I'm looking at buying the NFB-11 as well, as it appears to be the best value option out there, though the issues you've described are a bit discouraging.
Has anything changed in the past two months regarding the software? Or do the issues persist?

 
 
Software issues are under control, just a few "VIA ASIO drivers" BSOD in these months. Also I've learned how to free the audio device when an application takes the control and does not release it. Anyway, driver and software are not the strongest feature of this device.
 
Also, output power ratings given by Audio GD in their web page are not realistic, the Audio GD NFB-11 is only able to drive the Hifiman HE-500 with the volume knob and gain at maximum. Kingwa Watts are clearly lower than real world watts.

 

[Gloomy Moonie]

Would 

   
 
Software issues are under control, just a few "VIA ASIO drivers" BSOD in these months. Also I've learned how to free the audio device when an application takes the control and does not release it. Anyway, driver and software are not the strongest feature of this device.
 
Also, output power ratings given by Audio GD in their web page are not realistic, the Audio GD NFB-11 is only able to drive the Hifiman HE-500 with the volume knob and gain at maximum. Kingwa Watts are clearly lower than real world watts.

Would you recommend it, or should I be looking at something else? Looking to spend about $300-400, and I would prefer to get the best this money can buy.

 

[kishorfarm]

  Would 
Would you recommend it, or should I be looking at something else? Looking to spend about $300-400, and I would prefer to get the best this money can buy.

 
All in all, I think it's a very good DAC/amplifier combo for the price with an excellent sound and build quality. I don't know a better option for the price.
 
The only drawback is when driving very demanding headphones like the HE-500, then you can reach the limit of the amplifier, specially if audio tracks have a very large DR. And is not that it does not work, I'm using it to drive my HE-500 and it works well, but sometimes I wish it had more power. This is my biggest complain, that the output power figures claimed by the manufacturer are not realistic and that buyers can feel kind of cheated by this.
 
I previously had the Epiphany O2/ODAC and I like the NFB-11 much more. Other option with more output power is the Violectric V90, but it is more expensive and does not include the DAC.

 

[Gloomy Moonie]

   
All in all, I think it's a very good DAC/amplifier combo for the price with an excellent sound and build quality. I don't know a better option for the price.
 
The only drawback is when driving very demanding headphones like the HE-500, then you can reach the limit of the amplifier, specially if audio tracks have a very large DR. And is not that it does not work, I'm using it to drive my HE-500 and it works well, but sometimes I wish it had more power. This is my biggest complain, that the output power figures claimed by the manufacturer are not realistic and that buyers can feel kind of cheated by this.
 
I previously had the Epiphany O2/ODAC and I like the NFB-11 much more. Other option with more output power is the Violectric V90, but it is more expensive and does not include the DAC.

Thanks, I appreciate the reply.
Fortunately, as it happens to be, there's a reseller of the Audio-gd gear where I live, so I'll try to listen to as much of it as I can before making a decision.