[mathi8vadhanan]

DX90's DAC section is great, but the internal amp section brings it down. Since the volume is digitally controlled on the DAC, it's at it best on Level-255.
With an external amp, the background is perfectly black, much better layering, instrument separation and spacious soundstage. E18s amp is also not that great mind you, it's good for SE846 (even though I can only stay between vol level 3 &4). HD700 can definitely use a much powerful amp with DX90. I'm at vol level 6-7 on E18, anything above it starts falling apart. I'm still hunting for a good Desktop Amp for the 700s.

 

[knorris908]

DX90's DAC section is great, but the internal amp section brings it down. Since the volume is digitally controlled on the DAC, it's at it best on Level-255.
With an external amp, the background is perfectly black, much better layering, instrument separation and spacious soundstage. E18s amp is also not that great mind you, it's good for SE846 (even though I can only stay between vol level 3 &4). HD700 can definitely use a much powerful amp with DX90. I'm at vol level 6-7 on E18, anything above it starts falling apart. I'm still hunting for a good Desktop Amp for the 700s.

I have similar experience with using the HD-650s. No-go un-amped. The sound is okay with the FIIO e17, but the HD-650s just come alive when I hook them up to the Sciit Audio ASGARD 2 desktop amp! They don't even sound like the same headphones. Wider soundstage, (slightly, not a "night and day" difference as it is already good.) deeper & richer layering, and the vocals are just immensely-clear. I don't have any issues with the background not being black with any combination between the DX90 and the HD-650s myself though.

But yes, the DX90 just sounds better TO ME with the volume maxed-out at 255 regardless of using 300ohm Sennheisers, or easy to drive sub-40ohm in ear monitors. The only reason why I ever need that external amp aside from the HD-650s is to keep the volume down on the easier to drive headphones so that I don't go deaf!

 

[borrego]

DX90's DAC section is great, but the internal amp section brings it down. Since the volume is digitally controlled on the DAC, it's at it best on Level-255.
With an external amp, the background is perfectly black, much better layering, instrument separation and spacious soundstage. E18s amp is also not that great mind you, it's good for SE846 (even though I can only stay between vol level 3 &4). HD700 can definitely use a much powerful amp with DX90. I'm at vol level 6-7 on E18, anything above it starts falling apart. I'm still hunting for a good Desktop Amp for the 700s.

 
I had the same conclusion as yours on the DX90 line out and DAC chip level volume control. However, do expect your post to be followed by 10+ posts claiming how the 32bit DAC chip level volume control is bit perfect and is better. You could then argue with the better signal noise performance at volume level 255 but people will still claim there is no discernible difference. Good Luck.

 

[knorris908]

   
I had the same conclusion as yours on the DX90 line out and DAC chip level volume control. However, do expect your post to be followed by 10+ posts claiming how the 32bit DAC chip level volume control is bit perfect and is better. You could then argue with the better signal noise performance at volume level 255 but people will still claim there is no discernible difference. Good Luck.

Good point!  I just went back and amended my previous statement about the DX90 sounding better maxed-out at 255 to include "TO ME" so that it doesn't spark a debate.  I have no empirical data to back it up/discredit it, so there is nothing to debate. It's just personal preference/opinion to me.  People can only agree or disagree based on how it sounds to THEM.  Even if it's just in my own mind, music just sounds "fuller" to me when I have the volume at 255 through the line out and lower the volume through the external amp than if I have the DX90 turned down to say, 200 and turn the amp up.

 

[goodvibes]

I don't think it's the amp section unless it's a more difficult to drive device and HD700s may qualify. On IEMs or lower impedance phones most folks use, if you like it better, it's simply that you've found a preferred interfacing as opposed to the amp being sub par. Nothing is perfect and sometimes you can find things that are complementary. At the end of the day, whatever works for you is the right way to go. It's absolute type comments about the VG amp stage not being good enough that gets folks to correct things. You do realise that when you use an amp, there will also be a higher % of noise to signal as you lower the V control. It's not that it doesn't happen on the CX90, it's just that it's no different than using an outboard amp with the V less than 100% and since the noise level is quite low regardless of volume setting, there is no point to the comment unless you prefer DAPs without volume controls anywhere in the chain.

 

[headwhacker]

lol Using a full size headphone and you guys complain the internal amp is a let down? :confused_face_2:

Can you give me a similar DAP as DX90 where your HD700 or 650 is very satisfying as you are expecting of a desktop amp straight out of the HO.

I understand some prefer it stacked with an amp using iems. But that is nothing more than a personal preference.

 

[Lightless]

DX100 maybe?

 

[borrego]

I actually think the DX90 internal amp performs better with higher impedance headphones requiring volume setting at level 200 or higher. With low impedance headphones at volume set between 170 to 180, the internal amp just sound very flat without much soundstage depth and width.

 

[jamato8]

I actually think the DX90 internal amp performs better with higher impedance headphones requiring volume setting at level 200 or higher. With low impedance headphones at volume set between 170 to 180, the internal amp just sound very flat without much soundstage depth and width.

I guess it depends upon what headphones. I don't get that result with my headphones. 

 

[slickooz]

Yes the DX90 does improve with all my balanced phones with the SR71-B but not so much that I would have gone out and bought the amp for this purpose (except with the HE-500) but since I already had it I use and enjoy it.

 
I'm running SR-71B in single ended mode and I hear very minimum difference. People on here says after going balanced you will hear 25-30% improvement. I got the SR-71B hoping I will get the same results with my SE846, as I feel there some room to improve with my setup.  

 

[nc8000]

Single ended I don't find the SR71-B to be much of an improvement if any over the build in amp and even balanced I would not say 30-40% better but deffinately better, but the improvements going balanced also depends a lot on the phones, some gain more than others

 

[T.R.A.N.C.E.]

My opinion is that the internal amp of the DX90 is nearly faultless, it has better SQ than most portable amps, even high end ones. I do find that at low volumes the sound gets flatter, but my theory is that it's due to the digital volume though, not the amp. So the only two reasons for using an external amp for me are, 1- the dx90 is insufficient for powering your headphones and 2- you can hear audio degrading at low volumes like at ~170.

I think the DX90 would have been even more awesome with an analogue volume pot.

 

[slickooz]

In the Se846 thread a lot of them praise going balance, some of them are iPod users. Are they hearing +25% due to the fact they are running music from their iPod? I tried the iPod, and the DX90 to me destroy the iPod in every aspect. 

 

[jamato8]

My opinion is that the internal amp of the DX90 is nearly faultless, it has better SQ than most portable amps, even high end ones. I do find that at low volumes the sound gets flatter, but my theory is that it's due to the digital volume though, not the amp. So the only two reasons for using an external amp for me are, 1- the dx90 is insufficient for powering your headphones and 2- you can hear audio degrading at low volumes like at ~170.

I think the DX90 would have been even more awesome with an analogue volume pot.

Yes I like analogue pots but then you have the ones that wear out prematurely, get scratchy and people complain and then more imbalance problems so you have to weed out a lot. I know that Ray of RSA gets rid of around 40% and that is good pots. There is one good pot on the market but it is often too big for the form of the portable. Xin used it all the time and the balance is near perfect but you need a thick enough form to use it. 

 

[LoryWiv]

I'm a new and happy DX90 owner, and this forum has been a great resource. Recent reference has been made to upcoming new firmware and a signed Windows 64 DAC driver. Do any of the cognizenti on this forum have an ETA?

Thanks!