[castleofargh]

  The player is what it is. The difference between different headphones is probably more than the difference caused by impedance. I don't know how you are going to compare the effect of using two headphones with different impedances and not have them be significantly different responses too. The headphones are what is different in the equation, not the amp.

sure, but here the OP was concerned about the reverse situation, different daps having different sounds while supposedly measuring the same.
so we end up talking about how the output impedance can affect some headphones, and why 2DAPs with different impedances might explain why they do sound different on some headphones.
so checking the impedance might explain the OP question, and making sure the specs where showing the entire picture is part of the problem.
 
it's just one possibility, but it does happen more than we know with IEMs.
if EQ settings in daps were all good,  I wouldn't care really, but on non android sonys the last slider to lower the bass is at ... 400z. on the X3 you have 2 sliders, BASS, TREBLES... and some just don't have any EQ at all like the hm901. so considering the output impedance goes beyond driving power with most multi BA IEMs.

 

[Claritas]

I've found the chip manufacturer to be easiest indicator, regardless of implementation. For example, you can count on Sabres to reproduce with great clarity but have a certain uncomfortable sizzle. Wolfsons tend to be warmer but correspondingly a little fuzzy and rolled off. Cirrus is somewhere in between, but closer to Sabre. I don't know what makes the different chips sound different, but they do.

 

[bluesyfluesy]

That's what I used to think... Maybe it's placebo or the implementation of the DAC + components like the amplifier that gives a dap a "colour"?

 

[Music Alchemist]

Not sure what all determines the coloration of a DAP, but when I installed Rockbox on my iPod Classic, everything became much more clear, sharp, and possibly more neutral; unfortunately, it gives me a headache sometimes. I haven't researched how to effectively work with the EQ settings yet.

 

[Claritas]

That's what I used to think... Maybe it's placebo or the implementation of the DAC + components like the amplifier that gives a dap a "colour"?

Or maybe they simply sound different. I try to use whatever sounds best to me, if I can find it in a form I like. For example, I'd like a Wolfson version of ODAC or something small using a Wolfson chip.

 

[stv014]

That's what I used to think... Maybe it's placebo

 
Much of the time it is, at least as far as DAC chip and op amp "signatures" are concerned. The amplifier can make a real difference if it has too high output impedance, especially with IEMs. One can also hear differences due to different DSP/EQ settings, or just not matching the volume accurately enough.

 

[castleofargh]

dac chips require different implementations. a sabre being the most demanding, I guess, on quality architecture and power supply. it probably limits what you can competently do with it(I'm not talking 15$ hifimediy). that in itself might lead to a certain homogeneity of the sabre products. also sabre was offered as the hifi high spec stuff, anti jitter, anti noise, anti everything. so people using it made dacs for the expecting public of something mostly neutral and super clean sounding.
 
wolfson gained a reputation of warmer softer sound, probably because of the first products that came with it, maybe in part because it could be used on low power stuff for portables dap, and that could have resulted in bloated or distorted bass giving a feeling of them being emphasized? maybe the products with wolfson became warm to follow the reputation they gained, because people were expecting that sound and didn't pay for a "cold" DAC.
 
 
anyway all those chips have by themselves super clean output values well below the audible levels, so obviously what could make an audible difference is what's around it and the implementation quality. I have no doubt that they all can output the exact same audibly transparent sound, be it cirrus, wolfson(cirrus bought them) or ESS tech.

 

[Claritas]

dac chips require different implementations. a sabre being the most demanding, I guess, on quality architecture and power supply. it probably limits what you can competently do with it(I'm not talking 15$ hifimediy). that in itself might lead to a certain homogeneity of the sabre products. also sabre was offered as the hifi high spec stuff, anti jitter, anti noise, anti everything. so people using it made dacs for the expecting public of something mostly neutral and super clean sounding.

wolfson gained a reputation of warmer softer sound, probably because of the first products that came with it, maybe in part because it could be used on low power stuff for portables dap, and that could have resulted in bloated or distorted bass giving a feeling of them being emphasized? maybe the products with wolfson became warm to follow the reputation they gained, because people were expecting that sound and didn't pay for a "cold" DAC.

anyway all those chips have by themselves super clean output values well below the audible levels, so obviously what could make an audible difference is what's around it and the implementation quality. I have no doubt that they all can output the exact same audibly transparent sound, be it cirrus, wolfson(cirrus bought them) or ESS tech.

At least that would account for my and others' experiences instead of just dismissing them as placebo.

 

[blades]

  sure, but here the OP was concerned about the reverse situation, different daps having different sounds while supposedly measuring the same.
so we end up talking about how the output impedance can affect some headphones, and why 2DAPs with different impedances might explain why they do sound different on some headphones.
so checking the impedance might explain the OP question, and making sure the specs where showing the entire picture is part of the problem.
 
it's just one possibility, but it does happen more than we know with IEMs.
if EQ settings in daps were all good,  I wouldn't care really, but on non android sonys the last slider to lower the bass is at ... 400z. on the X3 you have 2 sliders, BASS, TREBLES... and some just don't have any EQ at all like the hm901. so considering the output impedance goes beyond driving power with most multi BA IEMs.

 
An amplifier trying to deal with a headphone with a lower impedance than its own output impedance is about the only predictable reason for an audible difference.  The other one is really hearing bias.

 

[blades]

At least that would account for my and others' experiences instead of just dismissing them as placebo.

 
It really doesn't account for your experiences.  No audible difference has been found between any two DAC's with solid state output stages made in the last 20 years in a bias controlled listening test.  A tube output stage, of course, can add some audible distortion.  It is hearing bias.  I'm not dimissing it.  I'm merely explaining it.

 

[Claritas]

It really doesn't account for your experiences.  No audible difference has been found between any two DAC's with solid state output stages made in the last 20 years in a bias controlled listening test.  A tube output stage, of course, can add some audible distortion.  It is hearing bias.  I'm not dimissing it.  I'm merely explaining it.

I'm certainly hearing your bias.

 

[bigshot]

DACs all sound the same because they're *designed* to all sound the same. If they sound different, they aren't performing to spec and there's probably something wrong with them.

 

[castleofargh]

I agree as long as they really are audibly transparent, with relatively low impedance output from a neutral low distortion amp. but don't forget that there are a lot of products out there that are far from those specs.
to me the dac is the very last thing that would improve as the cheap stuff are already great, but when looking at DAPs, it's not hard to find products that aren't well done.
you want noise on very sensitive IEMs, get most sony DAPs.
you want high impedance to mess up your custom IEMs, get the original ak100.
you want colored sound, get almost any DAP, some even seem to get different signatures with different firmwares(I guess one is neutral and the other is "more neutral" ^_^).
looking for rolled off high and lows, get a cowon and use it with low impedance IEMs.
you're looking for all of the above at once? get a studioV.
 
neutral, transparent, low impedance, low distortion those aren't words we can use to describes most daps.

 

[bigshot]

Why do people insist on using IEMs that the DAPs weren't designed to be used for, and then blame the DAP for having bad sound? If you want to use IEMs just patch into the line out and plug in an amp designed to work with the IEMs.
 
The "sound" of a DAP is what comes out of the line out. The impedance is a function of the earphones.

 

[ab initio]

  The "sound" of a DAP is what comes out of the line out.

 
This point seems to be frequently missed with regards to DAPs and full sized DACs in general.
 
Cheers