[Solude]

I am wondering if the TCXO is what is missing to bring out the best in the DAC.

 
No.  The upgrade is to maintain a stable clock under temperature variations.  For what it costs, worth it but it won't change much if anything once the DAC is stable temperature wise.

 

[Liu Junyuan]

Has anyone had the opportunity to compare the NFB-28 with and without TCXO upgrade side by side?

I have the NFB-28 without TCXO (Not my intention. I would have ordered it but I was not aware of such an option when I purchased it). After spending a month listen to my LCD-XC with it and I am come to the conclusion that the DAC in the NFB-28 is lackluster. It doesn't to headphones as great as the LCD-XC justice and there is a lot more potential untouched in them.

I am wondering if the TCXO is what is missing to bring out the best in the DAC. However, I have a feeling based on how much feels like it is missing from the NFB-28 DAC that it is simply not because of the TCXO.

I guess small DACs and all in one units just cannot cut it for me anymore after owning a REF1 for so long.

Interesting. Is there any way for you to see if its the amp instead? Are you sure its a DAC problem? Also, are you running balanced or single ended?

 

[WhiskeyJacks]

   
I was definitely considering the 10.33 too.  My original plan was to wait until I got the HE-560 and then see how it sounded on the NFB-15 vs the GO SE (Wolfson vs Sabre) and then decide whether to go for the NFB-10 or NFB-28.  But I couldn't pass up the used NFB-28 when I saw it!

Did you ever try out the HE-560 with the NFB28? I have had quite a few amps this past year, and after my health failing I had to sell most of my amps and phones. However, I did keep my grill and pad modded HE-560(CCC Balanced 4pin xlr cable) and the NFB28(which was the best bang for your buck as far as all in one fully balanced units are considered.) I did have the GO1000 and the Alo Panam and the HE-560 sounded great with both, but as far getting the best detail, speed, and having the amount power, the NFB28 won me over with the HE-560. I also have the DX90 and the PB2 balanced amp, which sounds great as a pairing with my he-560 for when I am in bed or my chair away from my computer.  Let me know what you think of the combo, it took me a few days of adjusting to really appreciate it's sound.

 

[Stillhart]

  Did you ever try out the HE-560 with the NFB28? I have had quite a few amps this past year, and after my health failing I had to sell most of my amps and phones. However, I did keep my grill and pad modded HE-560(CCC Balanced 4pin xlr cable) and the NFB28(which was the best bang for your buck as far as all in one fully balanced units are considered.) I did have the GO1000 and the Alo Panam and the HE-560 sounded great with both, but as far getting the best detail, speed, and having the amount power, the NFB28 won me over with the HE-560. I also have the DX90 and the PB2 balanced amp, which sounds great as a pairing with my he-560 for when I am in bed or my chair away from my computer.  Let me know what you think of the combo, it took me a few days of adjusting to really appreciate it's sound.

 
Actually yeah, they both came in on Friday and I've been enjoying them for a couple days now.  I tested the HE-560 with all three of my DAC's (NFB-15, NFB-28 and my borrowed GO SE) and I like the NFB-28 the best.  It manages to pull of this trick of being detailed yet smooth.  It really tames the treble harshness that can be inherent to the 560 with the wrong setup.
 
I haven't yet had the chance to try the balanced out.  My parts for the new cable are arriving on Tuesday so hopefully by next weekend I'll able to give more feedback on that.  (This will be my first DIY cable so I'm giving myself a few days!  lol)
 
BTW - Big fan of the Malazan Book of the Fallen series, but I suspect that's not where you got your name from.

 

[Stillhart]

So I did some more testing tonight to compare the NFB-28 to my old NFB-15.32 and my borrowed Geek Out Signature Edition.  Here are my unedited notes:
 

15 DAC -- 15 amp vs 28 amp
-    28 bigger soundstage.  Noticeable side to side AND front to back
-    28 Fuller sound?  Less thin… slight difference
28 amp -- 15 DAC vs 28 DAC
-    28 Brighter, much more treble but not bad treble (no sibilance or unpleasant spikes)
-    28 more bass extension, more sub-bass body, but less dynamic mid bass  Bass drum is lifeless?
-    28 better female vocals
-    15 treble is a little harsh?  sibilant
-    28 has that digital treble
-    15 is a little more “musical” (blended, less separated).  28 is more analytical at the expense of musicality
-    15 mid-forward, better male vocals
28 amp -- GO SE DAC vs 28 DAC
-    GO more sibilant!
-    Very similar overall
-    28 more bass body, more dynamic bass
-    28 fuller
-    GO slightly lower noise floor
-    28 just a bit more engaging
 

 
All testing was done with the HE-560 and with WASPI exclusive mode enabled for bit-perfect playback.  EDIT - Also this was all with the SE connection on the NFB-28.  I don't have my balanced cable yet.  Those impressions are coming up in a few days!
 
Overall, I'm very pleased with the 28.  While the 15 was better in certain areas (most notably the bass dynamics), the 28 was better in almost every other aspect.  Worthwhile trade-off IMO.  The GO was really close to the 28, but just felt a little more... Sabre-y.  More sibilant treble, less dynamic bass.  Not by much at all... definitely not as big as the differences between the 15 and the 28 (which themselves aren't that big)... but enough that I preferred the 28.
 
So yeah, I'm happy to say that I'll have no regrets about selling the 15 and returning the GO at this point.  I'll miss the 15, for sure.  It was my first real DAC and it served me well.  But there's no point in keeping it now; the 28 is a clear step up.
 
Next step is hauling this over to the PS4 to see if the optical works from a different source.

 

[Liu Junyuan]

That is useful to observe each phase of your impressions, isn't it?

Comments on bass dynamics are going to need revision once you are running balanced, which is what the NFB-15 doesn't require to perform at its full capacity, and unlike the 28, which does require a balanced connection.

I find your diligent observations interesting but ultimately Im paying less attention to them until you acquire balanced cables.

 

[Stillhart]

That is useful to observe each phase of your impressions, isn't it?

Comments on bass dynamics are going to need revision once you are running balanced, which is what the NFB-15 doesn't require to perform at its full capacity, and unlike the 28, which does require a balanced connection.

I find your diligent observations interesting but ultimately Im paying less attention to them until you acquire balanced cables.

 
Thanks for reminding me of that!  I think comparing SE vs SE is a fair comparison, but I agree that the NFB-28 is designed to be used with a balanced connection so it should sound better.  I plan on doing similar observations comparing the SE to the Balanced once I have my balanced cable and I'll be sure to post impressions.  
 

 

[Liu Junyuan]

Thanks for reminding me of that!  I think comparing SE vs SE is a fair comparison, but I agree that the NFB-28 is designed to be used with a balanced connection so it should sound better.  I plan on doing similar observations comparing the SE to the Balanced once I have my balanced cable and I'll be sure to post impressions.  

No worries. I am keen on this unit so please keep us posted once you are running balanced.

 

[lukeap69]

Dame, can't use the popcorn smiley when using the mobile site

Interesting to hear the difference when using balanced connection.

Thanks for the detailed comparo. Very useful and enlightening.

 

[conquerator2]

I wouldn't put that much stock on balanced connections. I mean sure, the NFB-28 was designed to perform fully in BAL operation [vs the NFB-29's SE] but a Sabre will always be Sabre and XYZ will always be XYZ. It will still have Sabre treble, mids, bass, etc. 

 

[nigeljames]

  I wouldn't put that much stock on balanced connections. I mean sure, the NFB-28 was designed to perform fully in BAL operation [vs the NFB-29's SE] but a Sabre will always be Sabre and XYZ will always be XYZ. It will still have Sabre treble, mids, bass, etc. 

 
And Amen to that 

 

[jodgey4]

Kingwa has stated that the NFB-28 runs best balanced, and most reviews seem to support that. Let the man write the review .

 

[Stillhart]

  Kingwa has stated that the NFB-28 runs best balanced, and most reviews seem to support that. Let the man write the review .

 
Oh I'll be writing it either way.  :-D  
 
I think he makes a fair point though.  While I expect to see some changes from running balanced, certain things that I'm hearing are directly related to the DAC implementation and I wouldn't expect to see them change much.  But who knows.
 
My cable parts come in tomorrow and I should have a working cable within a few days for some testing.  I'm also building an XLR->TRS adapter so I can quickly A/B without having to swap the entire cable.  Then I'll know!

 

[Liu Junyuan]

Yeah, no one is saying balanced is going to perform a miracle, but what Kingwa has said and what he posts on his site is that the NFB-28 must be running balanced to sound its best. He recommends the NFB-29 for those who do not run balanced. This has been said in this thread before. The boosted psu in the 29 compensates for its single-ended connection. It seems that if one does not want "to put too much stock into balanced," one has bought the wrong model of A-GD gear. Also, while the Sabre DAC is at issues here, so also is the amp, which depends on balanced to get a fuller grasp on those HiFiMAN drivers.

Looking at the specs online ( http://www.audio-gd.com/Pro/Headphoneamp/NFB282015/NFB282015EN_Specs.htm) the NFB-28 puts out less than half of its current into 40 ohms when running single-ended instead of balanced--2500 mw, as opposed to 8000 mw in balanced. That is arguably very significant.

Since the NFB-29s beefier psu also puts 8 watts of current into 40 ohms, I think it is fair to withhold strong judgement until the 28 is at least on equal footing as it's less expensive sibling, and I would guess Kingwa had in mind the same idea when he wrote on the product description

"If customer like to keep your headphone with single ended connector (6.3MM), choice the NFB-29 get better performance than the NFB-28.If customer had the balance connector headphone or can modify the headphone with balance connector, choice the NFB-28."

Since Stillhart has balanced parts on order, he understands what Kingwa was saying here and realizes that while it is useful to form initial impressions and share them with others, more precise conclusions are yet to come and hence potential purchasers of this unit like myself should be patient until that cable is up and running, exploiting the amp's full sonic potential.

I have listened to the Oppo HA-1 extensively with the 500, my dad's 560, and my HD 650s. It sounded very clean and detailed on all headphones, dynamics were great, and air and soundstage just right. I was running balanced for both HifiMANs. If the 28 can compete with the Oppo, I am very interested in picking one up as my yearly big audio purchase. So I am keen to hear what Stillhart, who has heard the Oppo, has to say about this, particularly in a couple weeks, after he has had some more time with it running balanced.

 

[Stillhart]

snip

I have listened to the Oppo HA-1 extensively with the 500, my dad's 560, and my HD 650s. It sounded very clean and detailed on all headphones, dynamics were great, and air and soundstage just right. I was running balanced for both HifiMANs. If the 28 can compete with the Oppo, I am very interested in picking one up as my yearly big audio purchase. So I am keen to hear what Stillhart, who has heard the Oppo, has to say about this, particularly in a couple weeks, after he has had some more time with it running balanced.

 
Actually, I haven't heard the Oppo.    I was considering picking one up at one point, but decided against it.