[audiopoor]

I'm pretty sure that all three of those BB OPA2134's are in the signal path so upgrading all of them should be fine.  The thing is that the only dual op amp that is better on paper without tradeoffs here and there is the National 4562.  In circuit the differences would be slight if audible at all.  The 2134 is a FET input design, however, and it might sound slightly warmer overall than the newer, but slightly quieter 4562.
As for the pot, the one in use is apparently a high grade conductive plastic (inherently low noise) one.  I believe the rotation noise is caused by a slight amount of output dc offset (mV) from the op amps, whose outputs are thankfully not capacitor coupled to block the dc from the pot sections.  No one wants any electrolytics in the signal path and the large value film caps that would be required as the better alternative to block the dc offset would never fit in the case.  I cannot believe anyone is bothered by the rotational noise.  It has nothing to do with elegant engineering and everything to do with sound quality.  To me it is nothing to waste time thinking about.  Trust me.  We do not want our volume controls on a chip.
I got my new E9 yesterday and after letting it warm up for a half hour I gave it a listen with my also new ATH-A700's.  At first listen I was very disappointed.  Now I'm a music lover/audiophile and because I have a 40 year collection of vinyl and cd, I'm not into computer audio or games for that matter.  Maybe I have a different sonic reference point than most portable/computer/game heads but I thought the E9 sounded awful.  As an amplifier designer I can tell you that amps do burn in but the sonic changes are slight unless we are talking about old electrolytics in use (rare) that have not undergone complete reforming.  Transducers do benefit from break-in but while there are sometimes sonic improvements they are never dramatic, imo.
Anyway I found the E9 to be highly colored, bright, shrill, lacking in low end depth and quality, but surprisingly stone quiet.  I modified the switching power supply lead with ten turns around a silicon steel core, but it's doubtful I zeroed in on whatever switching harmonics are reaching the E9, but it's likely not necessary anyway.  Previously I was listening to my preamp's headphone output which is built around the pathetic, ancient 4556 headphone specific op amp.  That it sounded better to me than the E9 had me scratching my head let me tell you.  I'm traumatized.
Looking at the E9 internals, I can see no components which might contribute to this sound character and I see no coupling caps or what would appear to be coupling caps.  A review of the E9's impressive specs. would give one the expectation of outstanding sound quality.  It could be the new headphones so I'll listen again later tonight with my older 990's or 580's for comparison.  For the hell of it I left the combo playing with a pretty dynamic cd on repeat at mid volume for about 12 hours.  I'll let you know what transpires with some of my other phones.  I really don't want to return the unit which essentially cost nothing in real dollars at only $129.

 

[estreeter]

Quote:

Anyway I found the E9 to be highly colored, bright, shrill, lacking in low end depth and quality, but surprisingly stone quiet. 

 
@audiopoor, I gave similar feedback a page or two back, and others have echoed that, but I think we need to give the amp a few hours. Mine has cleaned up after about 20 hours (I dont leave electrical appliances on while I am at work), but it has a considerable way to go before I will accept the 'liquid mids' claims made by others in this thread. I look forward to apologising to them by Sunday night, hopefully
 
(if not, as you said, we didnt spend a fortune. As you know, you can spend a lot more in this hobby and be equally, if not more, disappointed. With the exception of the coloration, early impressions of the Benchmark DAC1 arent a whole lot different to the description you give above. Whether its our ears or the amp section, I cant say, but the burn-in phenomenon is real IMO)

 

[MickeyVee]

Quote:

Anyway I found the E9 to be highly colored, bright, shrill, lacking in low end depth and quality, but surprisingly stone quiet.  

Same here when I first got it.  I let it run continuously for 5 days varying the volume from time to time.  it smoothed out and now about a month later using it a couple of hours a day, it has smoothed out.  With the HD600's, I find that there is little to no coloration.. almost clinical. You're right, it's pretty much has a dead black background. Almost eerie.  With a good source, it's pretty awesome.  Give it time.
 

 

[Mad Lust Envy]

Ii don't know if estreeter is referring to me, but I never said the mids were liquid. i said the E9 is mid forward compared to the Lyr or any sources I have used. My E9 has a substantial amount of use.

 

[estreeter]

I'm not referring to you, or any single Head-Fier, MLE - several people have made this claim. I cant find the 'Portable Amps' thread, but someone responded to my suggestion that the P4 may even have some advantages over the E9 in sonic terms by saying that the P4 is very good, but I simply would never get the liquid mids he was enjoying with the E9.
 
All I can say is that the P4 is very clear and scales beautifully with each turn on the volume pot (unlike my D4), but both amps are ridiculously powerful with low-impedance/high sensitivity cans. Anything beyond 9am usually starts to hurt, moreso with the analog out from my MSII than the Fiio L1 dangling from my Nano. In either case, I think there is a very real risk of permanent hearing damage if you are one of those who like to plug IEMs before turning your source and amp on.
 
 

 

[scannon18]

Quote:

Quote:

Same here when I first got it.  I let it run continuously for 5 days varying the volume from time to time.  it smoothed out and now about a month later using it a couple of hours a day, it has smoothed out.  With the HD600's, I find that there is little to no coloration.. almost clinical. You're right, it's pretty much has a dead black background. Almost eerie.  With a good source, it's pretty awesome.  Give it time.
 

Wow, that sounds like 200-300 hours of burn in.  I'm three days in, about as many hours.  Does anybody else think that the soundstage is a bit cramped?
 
 

 

[estreeter]

scannon, I have to question your arithmetic on that estimate:
 
1. 5 days continuous @ 24 hours per day = 120 hours
2. 30 days @ 2 hours per day = 60 hours
 
That's 180 hours max, according to my fingers-and-toes calculation - less than 8 days of continuous operation. You only have 5 days to go ......
 
Personally, I've adopted the Deckert approach to burning mine in, but use whatever gets you to the point where you are happy to listen to your rig. For some, that will mean just listening to their amp for as many hours a day as possible, and I'll be doing a lot of that this weekend.

 

[MickeyVee]

Yup.. 160-180 hours sounds about right.. for me, about 150 hours was the magic mark. Noticed that I was really liking it about a week ago.

 

[scannon18]

Quote:

scannon, I have to question your arithmetic on that estimate:
 
1. 5 days continuous @ 24 hours per day = 120 hours
2. 30 days @ 2 hours per day = 60 hours
 
That's 180 hours max, according to my fingers-and-toes calculation - less than 8 days of continuous operation. You only have 5 days to go ......
 
Personally, I've adopted the Deckert approach to burning mine in, but use whatever gets you to the point where you are happy to listen to your rig. For some, that will mean just listening to their amp for as many hours a day as possible, and I'll be doing a lot of that this weekend.

5 days continuous= 120 hours
30 days @ 3 hours per day= 90 hours= 210 total hours.  200<210<300
 
He did say a couple of hours, which technically is 2, so I'll quote my favorite president by saying that it depends on your definition.
 

 

[audiopoor]

Well you were all correct.  My E9 is sounding mighty sweet and clean right about about now.  I admit to being a little embarrassed and bewildered by my initial response to my new E9.  How could there be such a difference?  I cannot believe that any such device using current (modern) generation components could change its sonic signature so radically after any use, let alone after only 20 hours or so.  I guess anything's possible although I'm much more inclined to "blame" the also brand new ATH-A700 phones or maybe the switching power supply, the E9's only weak link on paper.
The E9 is noticeably fast.  I cannot ever recall hearing such fast leading edge transients, even with a super fast Spectral power amp I owned until recently.  Although no matter how fast an amp is, output to a loudspeaker is going to be slowed considerably relative to a headphone transducer, especially with a complex crossover in between.  There's no denying that the E9 is an unbelievable bargain.  Coming from the audiophile world, I'm accustomed to seeing such quality sell for way above $500.  Check out the headphone amps at the directed at audiophiles sites Music Direct.com, Audio Advisor.com or Acoustic Sounds.com catalogs and you'll see what I mean.  All three are about bending over the audiophile.  But OCD audiophiles deserve it because to most of them, if it's not expensive, it sucks.  Literally.
 

 

[scannon18]

Quote:

Well you were all correct.  My E9 is sounding mighty sweet and clean right about about now.  I admit to being a little embarrassed and bewildered by my initial response to my new E9.  How could there be such a difference?  I cannot believe that any such device using current (modern) generation components could change its sonic signature so radically after any use, let alone after only 20 hours or so.  I guess anything's possible although I'm much more inclined to "blame" the also brand new ATH-A700 phones or maybe the switching power supply, the E9's only weak link on paper.
The E9 is noticeably fast.  I cannot ever recall hearing such fast leading edge transients, even with a super fast Spectral power amp I owned until recently.  Although no matter how fast an amp is, output to a loudspeaker is going to be slowed considerably relative to a headphone transducer, especially with a complex crossover in between.  There's no denying that the E9 is an unbelievable bargain.  Coming from the audiophile world, I'm accustomed to seeing such quality sell for way above $500.  Check out the headphone amps at the directed at audiophiles sites Music Direct.com, Audio Advisor.com or Acoustic Sounds.com catalogs and you'll see what I mean.  All three are about bending over the audiophile.  But OCD audiophiles deserve it because to most of them, if it's not expensive, it sucks.  Literally.
 

Wow, you've covered a lot of ground for two posts.  I'm  glad your opinion of the E9 has changed.  It still bewilders me how solid state electronics can "burn in", but after the E9 I can't really doubt that it happens.
 
 

 

[Mad Lust Envy]

Glad to see people sticking with it and being rewarded by the E9 in the end. I don't remember ever having sound issues with the E9, though I did abuse it with burn in before I gave it an extensive listen. My E9 has a LOT of hours, lol. Its so good to me, I have no real reason to upgrade from it as my SS amp. It has great synergy with the D7000.

 

[scannon18]

MLE, I'm not sure if you have been over this yet, but how does the HE-4 pair with the E7/E9? I ask because I am looking at the he-4 as my into to orthos and am wondering if I need to buy a new amp first.  I'm sure your Lyr powers them much better, but any thoughts on E9->He-4 would be appreciated.

 

[estreeter]

I was happy to just get to the point where I could listen to the amp without wondering if I had a faulty unit - that was somewhere south of the 50-hour mark and now I'm just enjoying it. I know its antithetical to the whole point of buying a budget amp, but is there a sub-$100 alternative to the stock wallwart ? I'm not about to have the house rewired simply to get 'better sound', but if there is something else out there it would be good to have that option.
 
The other thing that hit me this morning was that this is a potential 'gateway drug' to more expensive solid-state amps. While I previously told myself that I wouldn't get enough use from an $850 amp I have been lusting after for a couple of years, the E9 has me wondering just how good this amp will be. Sadly, the law of diminishing returns tells me that it wont be 6 times as good, but dreams are free.
 
Anyway, earlier rants aside, kudos to Fiio for putting this amp together for so little money. Its possibly the ugliest electronic device I've ever owned, but it does what it says on the box, much like my HRT MSII. Hide that pairing behind a curtain and invite your friends around for a listen to your 'mystery rig' sometime

 

[Mad Lust Envy]

MLE, I'm not sure if you have been over this yet, but how does the HE-4 pair with the E7/E9? I ask because I am looking at the he-4 as my into to orthos and am wondering if I need to buy a new amp first.  I'm sure your Lyr powers them much better, but any thoughts on E9->He-4 would be appreciated.

The E9 drives the HE-4 to absurdly loud levels, but you can tell its not driving to their potential. Bass is loose, and detail is spread thin. I mean, the HE-4 will likely still sound better than probably anything you may have used, but it really begs for more than what the E9 has. The E9 won't make the HE-4 clip or distort with anything I've tossed at it, but its missing a bit of the fullness that the HE-4 is capable of. You would be happy with the HE-4 on the E9 as a temp measure, but I'd advise on getting some real power for them like the Lyr or HF5.

I'm so happy with the HE4 that I don't even wanna go further into ortho land. These babies are a slap to the face after having spent so much on mid range dynamics. They are THAT good. You'll never look back...