Audio-gd NFB-5, 9 switchable filters
Oct 3, 2011 at 4:36 AM Post #151 of 177
Use ceramics and tantalums instead.  The tantalum capacitors are polar, so the + side of one cap must face pin 8 and the - to ground, on a second cap the - side faces pin 4 and the + to ground.  The ground terminals are towards the back.  Ceramics are non-polar, so you add them whichever way.  You can also use these caps with killer IC opamps like OPA602BP, which will put those "discrete" opamps to shame.


Himm I might try them later but I seriously dont think its going to make much or any difference..


 
Oct 3, 2011 at 4:44 AM Post #152 of 177
Opamps, even "discrete" ones, hate power supply ripple.
 
Edit: In the end, if you do not like it, you can always go opamp-less as it isn't even necessary in the NFB-5 (hence its opamp bypass modes).  (I should have mentioned this first.)
 
Oct 6, 2011 at 9:18 PM Post #153 of 177
Ok so i got the HD650, the headphone meets all my needs for sound.. it does sounds very nice!.. Female voices and Jazz have never sounded better!
 
Had a brief play with ALC889 vs NFB-5. Everything definately feels tighter, but my impressions are pretty similar with the HD555's.
Its not a massive improvement.
 
I can hear the differences in the flavors a wee slight bit more.. but its still super subtle, and mainly all I can say is a couple of filters are pretty horrible, but others that sound good are all very similar..
I've left it on filter 2.
 
 
The diff between ACSS and the Moon OPA, is still very small. all I can say is the moon is smoother.. but this could definately be placebo.
Now my thinking are there any top of the heap OPAMPS i should try.. 
 
with some reading a lot of people suggest the AD797? will that work on this guy?
Or are the HDAMS pretty much the top of the pile already? should i give the Earth or the Sun a go?
 
I'm mainly looking for more soundstage and higher end detail, without losing any bass, mids. (those are currently ok) my only comparison is my friends Marantz AVR, which gives me a more 3d effect but the sound signature is quite similar.
 
i dont think i'm ready to try the bursons, at $100 its abit too exp.
 
Oct 6, 2011 at 9:26 PM Post #154 of 177
The ada4627-1brz did wonders for the Audio-GD FUN in terms of resolution and weight/slam of instruments. I found it to accentuate the HD650's strengths and suspect it may have the same effect in the NFB-5.
 
Oct 6, 2011 at 10:53 PM Post #155 of 177
I'd rank the HDAMs as mid-tier.  Top-tier would be ADA4627-1B, AD797, OPA602B, and a few others.  I think AD797 sucks when "rolled in blindly", but with bandwidth limiting caps in the feedback and psu bypass, it's a killer opamp!  4627-1B is such an improvement over the HDAMs, even when it is oscillating to death, lol, and then when it is stable, it is even more incredible.  It sports the clearest, airiest, most transparent treble I've heard yet in an opamp as well.
Ah well, I can't blame anyone for liking OPA Sun, it's the only HDAM I haven't sold off.  =p
 
Oct 9, 2011 at 11:49 PM Post #156 of 177
ok i got me some ADA4627-1B and ADA4637-1A 's .. got some logic boards from ebay.. will be interesting to see how it goes..
 
now one thing i dont understand is the "bandwidth limiting caps"  i've seen some caps across the power supply pins. 
 
What do you guys use for this? do u have a specific value that u just use? or should i just leave the caps off for the moment.
 
 
 
Oct 10, 2011 at 3:04 AM Post #157 of 177
You add them in parallel to the feedback resistors.  22pF for 4627, but for 4637 you will have to use larger values, probably around 82-84pF, whichever sounds better.  Add a 1uF tantalum and a 10nF ceramic across the power pins.
 
Oct 11, 2011 at 8:10 AM Post #158 of 177
 
Quote:
You add them in parallel to the feedback resistors.  22pF for 4627, but for 4637 you will have to use larger values, probably around 82-84pF, whichever sounds better.  Add a 1uF tantalum and a 10nF ceramic across the power pins.

Sorry, absolute noob here, but i dont really want to touch the NFB's actual board. 
I assume there may be feedback resistors across certain pins of the conversion board? although.. NFB specifically stands for non-feed-back.. not sure where that applies.
 
so i grab a 22pF cap, and add that somewhere? what kind of capacitor?
and also you mention 1uF And a 10nF across the power pins? pins 4 & 8 of the conversion board.
 
so is that 3 caps crossing various pins?
Any specific brand of capacitors for "audiophile" use? or just your generic ones will do..
also dont know what type (tantalum/ceramic) does what, but why the two types of caps across the power pins?
 
.. lol.. is there an FAQ i can read?
 
 
 
 
 
 
Oct 11, 2011 at 7:05 PM Post #159 of 177
Oh crap, right, non-feedback.  I'd have to look at the board.  Then one tantalum and one ceramic across the pins 4 & 8, make sure you add it on the bottom (the minus side of the tantulum goes to pin 4), not the top or only one channel will benefit.  I've been using Kemets; Vishays and others available on Digikey should be as good as well, I think.
 
Nov 3, 2011 at 12:40 AM Post #160 of 177
 
[size=10pt]The bottom line question for the people who has owned the FUN and now owns an NFB-5: Is it worth upgrading to it?[/size]

[size=10pt] [/size]

[size=10pt]My Fun is an A version  (WM8741) + DIR9001 + EARTH OPA, the rest of my gear is on my signature, I also just ordered a Squeezebox touch to use it as transport so I will stop connecting my laptop trough the USB port.[/size]

[size=10pt] [/size]

[size=10pt]I don’t really care about the filters. But the dual WM8741 and better PSU is what makes me think about it. I mostly listen to cds and 16bit flacs, if relevant[/size]

[size=10pt] [/size]

[size=10pt]I was thinking that my next equipment purchase was going to be a pair of grados RS2i.... but I'm not sure now...  [/size]

[size=10pt] [/size]

[size=10pt]Also consider I'm in Mexico, so selling the FUN here will not be easy.[/size]

[size=10pt] [/size]

[size=10pt]What do you think?[/size]

 

[size=10pt]PS. I really love my FUN! :wink:[/size]

 
Nov 3, 2011 at 10:25 AM Post #161 of 177
Took a jump on this as I just bought some new DT770's (250ohm) to replace my dying K81DJ's.
 
Probably could have gotten something cheaper, but I figure I won't be upgrading for a while, so might as well spend a little more.
 
Will post some impressions when it gets here (so, give or take a few weeks :p)
 
Dec 3, 2011 at 8:38 PM Post #163 of 177
If the SE output of the NFB-10SE is any indication, quite good, but I could hit max volume with classical easily without it getting very loud.
 
Feb 14, 2012 at 10:43 PM Post #165 of 177
Got my NFB 5 today. This thing is extremely well built. Build quality is just fantastic.

Quick impressions:

9 Filters: all sound the same to me, might hear a thing here or there that's diff, but honestly, not worth noting. They are all 99.9% alike to me.

ACSS vs Stock opamp vs MOON

ACSS wins. By how much? Not alot. They honestly all sound almost a breath away from each other. If someone were to switch between ACSS to opamps, I wouldn't know aside from the noise it makes when it switches.

So opamps = worthless. Stick to ACSS.

USB vs Optical: can't tell any worthwhile differences. They both sound great.

Also hooked up the E9 to the NFB 5's line out (I set it to fixed). The E9 still compares great to the NFB 5. The NFB 5 IS superior. Less harshness in the treble, thicker sound, but the overall, uneducated ears wouldn't be able to tell the difference. I'm sure I'd fail blind tests, but yes, the improvement is there. I'd say maybe a 5-10% improvement. Very negligible, the same as opamp vs ACSS, ACSS being better by a hair.

I'm glad I got it. It's worth it to me as a great all in one with a boatload of power, which is something it clearly has over the E9. I just wish it had a line in for analog sources, but it's not essential.

Guess it's time to unload the MOON opamp. PM me if interested.
 

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