[Fungus]

 
the line out could/should use standard values, but like anything else, between the incompetent designs, the false line out that is just the HO at max volume, and the clever little guys who thought that if they made the line out a little louder, most people would believe the sound to be superior in listening tests without matched volumes, we end up with pretty much whatever.
most of the times the max voltage will be around 1 or 2volt, and the impedance output should be around 1 or 2 hundred ohm(but can really be anything). so it can clearly affect the gain and overall loudness, but it can also make an amp clip. and there is no perfect choice as a low signal might have a higher noise floor, and hiss, or make your amp unable to get some headphones loud enough.
usually line outs on portable devices have lower voltage than desktop product line outs(ipod effect). so portable amps might tend to be designed for lower voltages and clip sooner than desktop amps in that particular situation.
the hm901 LO being louder might just be that it's the only one with a 2v LO while others are lower. I don't know, but sony certainly didn't output 2V into the LO of any walkmans I've owned. the fiio X3 had the loudest line out for me and it's given at 1.7v.

So basically there is no currently portable player on the market that has true line out and use standard values (any output less than 2v automatically indicated false line-out). If the false line out is just the HO at max volume. wouldn't it be better to just use the headphone jack cos then that way, the volume can be adjust digitally within the player itself?
 
How did you get the value of the max voltage and impedance output of 1 or 2 volts?
If the player with a lower signal has a higher change of causing higher noise floor, hiss or inability to driver headphone to louder volume. then what's the disadvantage of having a higher voltage say 2v?
 
Talking about 2v, I'm confused as to why Retrias found there to be high distortion from the hm901 line-out.
 
You trying all sony walkman players and none output 2v into the LO.  
 
What do you think of the sony hd5 network walkman?
There is a LO feature that can be activated in the settings allowing the LO to be used with the headphone jack. 

 

[streetcar]

http://www.lotoo.cn/page/Default.asp?pageID=93

 

[castleofargh]

Originally Posted by Fungus /img/forum/go_quote.gif
 
So basically there is no currently portable player on the market that has true line out and use standard values (any output less than 2v automatically indicated false line-out). If the false line out is just the HO at max volume. wouldn't it be better to just use the headphone jack cos then that way, the volume can be adjust digitally within the player itself?

I have to disagree with the less than 2v as a sign for false line out.  I mentioned false line outs because they do exist, but the output voltage isn't at all revealling of the type of line out. in fact a lot of HO can output 2volt or more at max level.
so you really have to know how the line out is for each DAP, and shouldn't dismiss a DAP only for it's line out max voltage.

Originally Posted by Fungus /img/forum/go_quote.gif
 
 
How did you get the value of the max voltage and impedance output of 1 or 2 volts?

with years wasting my time reading anything I could from any new and seemingly interesting DAP. I think old ipods were claimed to be around 0.5v.
you made me doubt myself so I just looked at http://en.wikipedia.org/wiki/Line_level
it seems like I didn't lie a lot ^_^.
 
 
 

Originally Posted by Fungus /img/forum/go_quote.gif
 
If the player with a lower signal has a higher change of causing higher noise floor, hiss or inability to driver headphone to louder volume. then what's the disadvantage of having a higher voltage say 2v?
 
Talking about 2v, I'm confused as to why Retrias found there to be high distortion from the hm901 line-out.

let's say an amp was built with the intent to be used with  sources that never get passed max 2V. then to benefit from the maximum dynamic, they would build the amp so that when it receives 2V, it would output the loudest possible signal the components can handle(the op amp usually) and it would make perfect sense to do that if you know you'll never get more than 2V in the input.
 
then in that situation what happens when the input goes to 2.1V? the signal becomes something that goes from -2.1V to +2.1V, but the amp is only able to deal with -2/+2V, all signals between 2 and 2.1V will end up getting out as being 2V. what we call clipping, the top of the wave is flatten until the input signal gets back down under 2V.
as I said ipods were known to have a very low LO, but as they sold so many around the world, it's only natural that some people started to make amps with mostly those low voltages in mind.
because obviously if your source was 0.5V instead of 2V, for some headphones you would have to use a higher gain value to listen loud enough. (maybe I'm saying something very wrong here, but I think twice as much voltage is +3B in loudness, so here we would feel like the 2V source could be twice as loud as the 0.5V.)
 
anyway it might be for such a reason that the HM901 clipped with some amps. because it can send more voltage than the amp can manage. (NB:the impedance values are as important as the voltage here as they change the voltage directly).
 
 
 

Originally Posted by Fungus /img/forum/go_quote.gif
 
You trying all sony walkman players and none output 2v into the LO.  
 
What do you think of the sony hd5 network walkman?
There is a LO feature that can be activated in the settings allowing the LO to be used with the headphone jack. 

I've tried only a few sony DAPs with the line out, A865, E585, F886. but none of them was as loud as the fiio X3 and the X3 is said to be at 1.7V. thus my conclusion. I never measured any LO myself. and the ZX1 should be very much like the F886 when it comes to the LO.
but again the voltage has nothing to do with the quality of a line out.
 
sorry I don't know the HD5, I actually never knew it existed ^_^.

 

[AUDIOBREEDER]

Looks like its taken out from PriceJapan

 

[Fungus]

  I have to disagree with the less than 2v as a sign for false line out.  I mentioned false line outs because they do exist, but the output voltage isn't at all revealling of the type of line out. in fact a lot of HO can output 2volt or more at max level.
so you really have to know how the line out is for each DAP, and shouldn't dismiss a DAP only for it's line out max voltage.
with years wasting my time reading anything I could from any new and seemingly interesting DAP. I think old ipods were claimed to be around 0.5v.
you made me doubt myself so I just looked at http://en.wikipedia.org/wiki/Line_level
it seems like I didn't lie a lot ^_^.
 
 
 
let's say an amp was built with the intent to be used with  sources that never get passed max 2V. then to benefit from the maximum dynamic, they would build the amp so that when it receives 2V, it would output the loudest possible signal the components can handle(the op amp usually) and it would make perfect sense to do that if you know you'll never get more than 2V in the input.
 
then in that situation what happens when the input goes to 2.1V? the signal becomes something that goes from -2.1V to +2.1V, but the amp is only able to deal with -2/+2V, all signals between 2 and 2.1V will end up getting out as being 2V. what we call clipping, the top of the wave is flatten until the input signal gets back down under 2V.
as I said ipods were known to have a very low LO, but as they sold so many around the world, it's only natural that some people started to make amps with mostly those low voltages in mind.
because obviously if your source was 0.5V instead of 2V, for some headphones you would have to use a higher gain value to listen loud enough. (maybe I'm saying something very wrong here, but I think twice as much voltage is +3B in loudness, so here we would feel like the 2V source could be twice as loud as the 0.5V.)
 
anyway it might be for such a reason that the HM901 clipped with some amps. because it can send more voltage than the amp can manage. (NB:the impedance values are as important as the voltage here as they change the voltage directly).
 
 
 
I've tried only a few sony DAPs with the line out, A865, E585, F886. but none of them was as loud as the fiio X3 and the X3 is said to be at 1.7V. thus my conclusion. I never measured any LO myself. and the ZX1 should be very much like the F886 when it comes to the LO.
but again the voltage has nothing to do with the quality of a line out.
 
sorry I don't know the HD5, I actually never knew it existed ^_^.

So it's all about getting the closest voltage match between the source and amp in determining the LO quality,or a least that's one of the factors.  
 
Is the value of the exact input an amp accepts generally listed in the spec sheet of each product? 
 
I guess there's no why to find the value input voltage of a player/source since companies don't release these specs unless people go and measure it themselves.   
 
I wonder what the output voltage of an imod would be. 

 

[dleblanc343]

I really need to sell my HM-901 so I can downgrade to this!
 
Anyone who wants an HM-901, now's your chance for a great deal

 

[toears]

  I really need to sell my HM-901 so I can downgrade to this!
 
Anyone who wants an HM-901, now's your chance for a great deal

Price ?

 

[dleblanc343]

Price ?

900$ for a like new HM-901 with upgraded IEM module. Everything is mint with packaging

 

[Dumbleroar]

 
256MB max.

I think you mean GB, it would be dreadful for them to release another device with only 256MB on. 

 

[Currawong]

   I mentioned false line outs because they do exist, but the output voltage isn't at all revealling of the type of line out. in fact a lot of HO can output 2volt or more at max level.

 
There's no such thing as a "true line out" or a "false line out". "Dedicated line out" would be a far better term. If one socket is used in a DAP for headphones and whatever "line out" setting then it is going to pass the signal through the same circuitry in all cases (unless there is some kind of internal switch). 
 
In almost all regular DACs, after the converter chip there is a gain stage for the line out. The gain stage isn't much different from those used in portable headphone amps, DACs and DAPs -- the opamps used are very often the same. The difference between regular hi-fi component sources is that their outputs have a much higher output impedance, as the input impedance of most (pre)amps is extremely high. As I understand things, as long as a DAP is as linear (or better) feeding a 10k Ohm input on an amp as it is driving headphones then it is a moot point, unless the voltage output is too low or too high for the amp's inputs. If the DAP has a dedicated line out for amps that skips a gain stage and has lower distortion specifically for feeding an amp, all the better for people who want to do that.

 

[Fungus]

   
There's no such thing as a "true line out" or a "false line out". "Dedicated line out" would be a far better term. If one socket is used in a DAP for headphones and whatever "line out" setting then it is going to pass the signal through the same circuitry in all cases (unless there is some kind of internal switch). 

I think that's exactly the case with the Sony hd5 which the headphone jack doubles as a line-out. 

I believe there's a internal switch or else it would just be pointless. 
 
I currently own one, my 3rd one actually and when the line out is activated within the setting and music is
played though a pair of headphones, the sound completely distort and gives of this weird high pitch noise,
very unpleasant!  
 
I wonder what's causing this phenomenon. 

 

[castleofargh]

 

   I mentioned false line outs because they do exist, but the output voltage isn't at all revealling of the type of line out. in fact a lot of HO can output 2volt or more at max level.

 
There's no such thing as a "true line out" or a "false line out". "Dedicated line out" would be a far better term. If one socket is used in a DAP for headphones and whatever "line out" setting then it is going to pass the signal through the same circuitry in all cases (unless there is some kind of internal switch). 
 
In almost all regular DACs, after the converter chip there is a gain stage for the line out. The gain stage isn't much different from those used in portable headphone amps, DACs and DAPs -- the opamps used are very often the same. The difference between regular hi-fi component sources is that their outputs have a much higher output impedance, as the input impedance of most (pre)amps is extremely high. As I understand things, as long as a DAP is as linear (or better) feeding a 10k Ohm input on an amp as it is driving headphones then it is a moot point, unless the voltage output is too low or too high for the amp's inputs. If the DAP has a dedicated line out for amps that skips a gain stage and has lower distortion specifically for feeding an amp, all the better for people who want to do that.

 in the end it all comes down to know if the output is clean enough and with about ok values in voltage and impedance. if it's super clean, I certainly dont mind where it goes, I'm not picky about the ways to obtain a great result, and I wouldn't mind using whatever is great and clean as a LO. but if the LO doesn't bypass the main amp section(and not the preamp at the DAC output obviously), then to me it would still be a "false LO". the all idea to put a LO on a DAP was to limit the multi amping.
either that internal amp section is bad like on so many DAPs and smartphones, and you do want to bypass it, or the amp section of the DAP is great stable and clean as you say, and then unless you need more gain, there there might be little value to using an external amp at all.
 
so even though some DAPs made great improvement with their amp section those last 2 or 3 years, the amp part of a DAP is still very much the usual suspect when it comes to audio quality problems. and bypassing it is to me the main way to significantly improve the sound on a lot of DAPs. 
when I was using an amp on my sansa clip or my old samsung YP-P3(mostly just to have a better volume control and deal with the poor soundstage on low impedance IEMs. crosstalk falling down with low impedance I guess) people were often willing to call the spanish inquisition to deal with me. since the AK100 came out, all of a sudden it was perfectly HIFI to use a HO into an amp. so obviously fashion has ephemeral opinions on the subject. but I'll keep my "false line out" expression as it is meaninglful to me not to label a sound quality but to describe a signal path.

 

[Cecala]

  I think you mean GB, it would be dreadful for them to release another device with only 256MB on. 

Yes of course. Correction standing.

 

[georgelai57]

So has any ZX-1 owner had any success pairing it with all these new portable wireless HDDs? I have great difficulty with the Seagate wireless HDD and I'm wondering if anyone has success with La Cie Fuel, WD, etc.

 

[johnston21]

I've paired it with the SONY WG-C20. Sounds fine but you need to use the WG's native app. Took 2 purchase as the 1'st gen C20 got borked by the early firmware.