Hiss-less player? How perfect is it, really?

Feb 21, 2008 at 3:27 PM Post #16 of 27
I still don't agree same dac will has same hiss.

And by the way, d2 and t39 does not have the same chip.

Cowon D2 = Telechips TCC7801 + Wolfson WM8985G
Teclast T39 = Telechips TCC8200 + Wolfson WM8978G

WM8985
headphone driver+dac: SNR 97db, THD -80db

WM8978G
headphone driver+dac: SNR 102db, THD -92

Then base on your theory, T39 has better signal to noise ratio.

Quote:

Originally Posted by shigzeo /img/forum/go_quote.gif
yes, i am very familiar with hiss. i can only see hiss that is detectable from the human ear coming from an amped source. dac, or line out should not make much or any noise that we can hear as the signal is pure without any magnification.

i have never heard any non md or pcdp that has not had some sort of hiss - some have less and some have so much that they are unlistenable. currently the teclast has a few people chiming about how good it sounds. but it has same dac as d2 - the output i am interested in however i am quite sure that as with every single player, it hisses.

as you said, the hiss can come form variety of sources. hd, screen, flash memory, cpu controllers etc. and as you know, the teclast has all of these. but even simple players like shuffle hiss.



 
Feb 21, 2008 at 11:19 PM Post #17 of 27
I hear hiss in most all portable audio products including mini-disc and portable cd players with shure e500's. Just some are very very low, I heard it on sharp mini dics, sony, and kenwood md hissed like crazy My 2 old pcdp's hiss also sony and pana, but these and the md is very very low. Some of my players fool you into thinking they have no hiss, but they kill the amp circuit when paused, but when you turn the volume down with the player running you can hear it
eek.gif
It's just the nature of portable audio. Unless something really cries, (kenwoods) I can live with it
biggrin.gif
Or as shig said, live with less sensitive iems.
 
Feb 22, 2008 at 1:26 AM Post #18 of 27
I hear virtually no hiss from my Zen Vision:M and E500 (the E500 being sensitive IEMs and prone to expose hiss on some players.) Whatever hiss is audible is from the source material itself, but virtually none from the player electronics.
 
Feb 22, 2008 at 1:33 AM Post #20 of 27
Quote:

Originally Posted by faichiu /img/forum/go_quote.gif
And believing or not, hiss can be reduce by adding resisitors to the output. So your concept of same hardware with same hiss just don't make sense to me.


It is best if analog circuits are shielded or designed to cancel noise
 
Feb 22, 2008 at 2:33 AM Post #21 of 27
That's true.

Quote:

Originally Posted by DJGeorgeT /img/forum/go_quote.gif
It is best if analog circuits are shielded or designed to cancel noise


 
Feb 22, 2008 at 2:51 AM Post #22 of 27
circuit paths should be kept short, audio should be separated from power supply and kept away from hard drives and sources of flicker. Component layout on the pcb is critical. Hiss free is possible. My sansa clip is very quiet. My Bozak mixer/phono stage/amp is practically noise free. I can turn the volume know clockwise all the way and it will be all quiet and this is quiet through the phono stage without playing records.
 
Feb 22, 2008 at 7:59 AM Post #23 of 27
signal to noise ratio has nothing to do with hiss. or very little to do with it. the headphone out may add hiss, the other components may add hiss. most players promise or advertise spec but they never ever perform near spec as they go through the runs after that.

i think sharp were very honest when in 2003 they advertised their auvi units that sound very good and with my um2 (my sharp auvi did not hiss at all) advertised s/n of 88db. the chips themselves don't supply the be-end of the system thus cannot determine the ultimate hiss.

i have seen discrepencies in published information on the teclast. no matter, i am sure it is a great player. but, very discrepency on the battery life, output power (as with d2) among other things. the internals may have changed too but the truth is that: amps hiss. portables have amps in them.

the person here who can hear hiss from the md players is the benchmark we should be listening to as i could not hear it from my 2003 auvi portable sharp nor my sony mzr-rh10. however, that is not to say it is not there. if you cannot hear it it does not mean it is not there, it means you cannot hear it.

i keep hoping for nothing but... after a while even hissless players have people come out and say... oh yeah, it hisses, but very little. my d2 caused me to sell my um2 - as i could not stand hiss anymore.
 
Feb 22, 2008 at 9:02 AM Post #24 of 27
So far the players I have heard the Cowon D2 and i7 and the iRiver Clix2 are the ones with the least hiss. I have the i7 at normal listening levels I am not annoyed by the amount of hiss. The only time where the hiss is a bit over the top is when the player boots. Otherwise it is very low.
 
Feb 22, 2008 at 12:10 PM Post #25 of 27
hiss is noise and I don't understand why is has nothing to do with signal to noise........The spec I bring up is from chipset company. Not from teclast.

Teclast spec said T39 only 20mW per channel but I found it has more power than d2 which advertise as 37mW per channel. I think cowon is the company that has discrepencies in published information and same with battery life.

My disagree with your statement saying that same chip has same hiss.
I did not disagree with all player has hiss......
I agree all players I have listen has hiss!

And I did said T39 has no hiss at the beginning.
But that just with the headphone I own at normal playing volume it has no hiss.
Some players has very notable hiss even with normal playing volume.
Example will be my D321 discman. NDS also hiss like crazy.

And also, I don't think DAC with go directly to output port without any other components like you mention.
One sample should be the very favor imod.
If you look at the imod page, you will see what's between dac and output.\Red Wine Audio iMod

Quote:

Originally Posted by shigzeo /img/forum/go_quote.gif
signal to noise ratio has nothing to do with hiss. or very little to do with it. the headphone out may add hiss, the other components may add hiss. most players promise or advertise spec but they never ever perform near spec as they go through the runs after that.

i think sharp were very honest when in 2003 they advertised their auvi units that sound very good and with my um2 (my sharp auvi did not hiss at all) advertised s/n of 88db. the chips themselves don't supply the be-end of the system thus cannot determine the ultimate hiss.

i have seen discrepencies in published information on the teclast. no matter, i am sure it is a great player. but, very discrepency on the battery life, output power (as with d2) among other things. the internals may have changed too but the truth is that: amps hiss. portables have amps in them.

the person here who can hear hiss from the md players is the benchmark we should be listening to as i could not hear it from my 2003 auvi portable sharp nor my sony mzr-rh10. however, that is not to say it is not there. if you cannot hear it it does not mean it is not there, it means you cannot hear it.

i keep hoping for nothing but... after a while even hissless players have people come out and say... oh yeah, it hisses, but very little. my d2 caused me to sell my um2 - as i could not stand hiss anymore.



 
Feb 22, 2008 at 5:35 PM Post #27 of 27
I just discovered a simple hiss test for portables. Turn the player on, set volume, but dont have any music playing. plug and unplug your headphones. if there is no difference in the noise from unplugged/plugged then walaa- no hiss.

doing this on the D2 and I car hear the difference using the c700. the hiss is extremely quiet and I dont usually notice it.

its possibly to have a inky black dap. youd think a higher end product with component layout and balanced analog paths could figure it out.
 

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