[ade_hall]

If you really want to know what chip it's using, then you have to take the back off:
 
http://www.head-fi.org/t/447836/hifiman-801-appreciation-thread/210#post_6622703

 

[ianmedium]

Thanks Ade, I went as far as taking the back plate off but underneath was just a large black plastic box.. I chickened out from there, will have a look at your link!

 

[ClieOS]

I believe Fang once said (over at erji.net, not here) that all the PCM1704 used on HM801 are the K variance, but that was quite sometime ago.

 

[ianmedium]

Thanks Clie. I am not going to tamper with my unit to find out. The sound is great and it was just idle curiosity! (BTW) I have bookmarked your blog.

 

[i_djoel2000]

Quote:

 
Don't know. But it shouldn't be too hard to find. You can just trace back from the headphone jack.

 
i did the output resistor mod just now.. and you were wrong clieos. it DOES improve the sound quality! 

 
the low bass becomes much more clearer and effortless, and overall the sound is more dynamic and open. thank you for pioneering this mod on 801 model clieos!
 
nb: impression was done with a westone es3x.

 

[ClieOS]

Well, I certainly didn't pioneer the mod. Some Russian guys were doing that much earlier than I did. But I didn't copy them, just coming out of the same idea at a much later time when I was investigating the impedance issue.
 
A good reason why you find it an improvement is because ES3X is multi-driver IEM with crossover. The lowering of output impedance immediately gives it a lot more power delivery and less coloration. On contrast, I mainly use RE0 and ER4S for my comparison and they are not sensitive to output impedance change.

 

[HungryDaze]

Quote:

Well, I certainly didn't pioneer the mod. Some Russian guys were doing that much earlier than I did. But I didn't copy them, just coming out of the same idea at a much later time when I was investigating the impedance issue.
 
A good reason why you find it an improvement is because ES3X is multi-driver IEM with crossover. The lowering of output impedance immediately gives it a lot more power delivery and less coloration. On contrast, I mainly use RE0 and ER4S for my comparison and they are not sensitive to output impedance change.

I should say that ER4S is quite sensive to output impendance.

 

[LarsHP]

I can't find the newest firmware for the HM-801 - the v0.23.
Anyone knows where to find it?
Or could upload it somewhere and put a link in this thread?

 

[KT66]

The HIFIMan web site only goes up to 0.21 
http://head-direct.com/News/?act=detail&id=214
 
this the version I currently use with no issues, and sounding superb

 

[LarsHP]

I also use v0.21, but apparently there is a newer (v0.23) one with EQ enabled.

 

[HungryDaze]

Quote:

I can't find the newest firmware for the HM-801 - the v0.23.
Anyone knows where to find it?
Or could upload it somewhere and put a link in this thread?

Here you go. http://nekaka.com/d/k9Uj1ke2O2
 
BTW, 0.19 is the best sounding firmware. Check it out. There is no problem with SD if you make a dualboot firmware (0.19 + Rockbox). 

 

[LarsHP]

Quote:

Here you go. http://nekaka.com/d/k9Uj1ke2O2
 
BTW, 0.19 is the best sounding firmware. Check it out. There is no problem with SD if you make a dualboot firmware (0.19 + Rockbox). 

Thanks!
Are you hearing a difference between the firmwares? And the latest isn't as good sounding as that old one?
What difference do you hear?

 

[HungryDaze]

Quote:

Thanks!
Are you hearing a difference between the firmwares? And the latest isn't as good sounding as that old one?
What difference do you hear?

I remember that 0.19 in comparison with 0.23 sounds fullier, rich, with better imaginary stage and attack. I compared HM-801 + SYMMcard amp with MyST PortaDAC 1866OCUB not so long ago. With 0.19 HM-801 sounds very similar to PortaDAC. Anfortunatelly I can't say the same about Rockbox or 0.23.

 

[ianmedium]

I remember that 0.19 in comparison with 0.23 sounds fullier, rich, with better imaginary stage and attack. I compared HM-801 + SYMMcard amp with MyST PortaDAC 1866OCUB not so long ago. With 0.19 HM-801 sounds very similar to PortaDAC. Anfortunatelly I can't say the same about Rockbox or 0.23.

Thats interesting. What is lost in terms of features and usability in going back to 19 from 23?

I suppose if I did not like 19 I could simply reload 23?

 

[HungryDaze]

Quote:

Thats interesting. What is lost in terms of features and usability in going back to 19 from 23?

I suppose if I did not like 19 I could simply reload 23?

Nothing will be lost, you will even gain a proper auto power off after timeout. All the SD cards work properly if you make a dualboot firmware (0.19 + Rockbox).
 
Yes, you can always return the 0.23.