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

Can anyone open up their dock-1 and take a picture of the inside? I'm curious to see how well the power filtering and 3v line out is implemented and what kinda op amps they went with etc.

 

[KT66]

My 901 has developed a weird fault. 
 
If I accidently hit the balanced/normal switch, to balanced, I lose
about 50% of the right hand volume. (I don't use balanced 'phones or cables btw)
 
If I switch it back, the problem remains. However if I switch it lots and lots of
times quickly the right channel comes back, most of the time.
 
I tried an external amp via the line out and the issue was confirmed, using line out it was perfectly balanced in both channels.
I took out the mini box, replaced it, then switched back to standard amp card 
(not a lot of difference btw) and the problem came back, and stays using headphone output.
 
If the switch is set to balanced and I am using normal headphones,in  this case
T70P, what should I hear? or what do you hear?
 
Anyone else experienced this at all? or is it a send back to China job?

 

[jamato8]

  My 901 has developed a weird fault. 
 
If I accidently hit the balanced/normal switch, to balanced, I lose
about 50% of the right hand volume. (I don't use balanced 'phones or cables btw)
 
If I switch it back, the problem remains. However if I switch it lots and lots of
times quickly the right channel comes back, most of the time.
 
I tried an external amp via the line out and the issue was confirmed, using line out it was perfectly balanced in both channels.
I took out the mini box, replaced it, then switched back to standard amp card 
(not a lot of difference btw) and the problem came back, and stays using headphone output.
 
If the switch is set to balanced and I am using normal headphones,in  this case
T70P, what should I hear? or what do you hear?
 
Anyone else experienced this at all? or is it a send back to China job?

I haven't had this problem. Seems something might have some debris or maybe something does need to be taken out and cleaned. Have you tried pure alcohol on the TRS and inserted it to clean the contacts? I do this a few times with fresh alcohol each time. Works sometimes, depends upon what the real problem is. 

 

[fengwei007]

My 901 has developed a weird fault. 

If I accidently hit the balanced/normal switch, to balanced, I lose
about 50% of the right hand volume. (I don't use balanced 'phones or cables btw)

If I switch it back, the problem remains. However if I switch it lots and lots of
times quickly the right channel comes back, most of the time.

I tried an external amp via the line out and the issue was confirmed, using line out it was perfectly balanced in both channels.
I took out the mini box, replaced it, then switched back to standard amp card 
(not a lot of difference btw) and the problem came back, and stays using headphone output.

If the switch is set to balanced and I am using normal headphones,in  this case
T70P, what should I hear? or what do you hear?

Anyone else experienced this at all? or is it a send back to China job?

It's one of the issues some 901 users have. You can try to clean the contacts on the amp cards (but not likely it's due to this since it happened on two different cards) and the player (where the cards go in), you also can just push/pull the balanced/unbalanced switch up and down some times (50-100 times?) so to clean the dirts underneath. If all these fail, probably it's time to go back to service center.

 

[frankrondaniel]

  My 901 has developed a weird fault. 
 
If I accidently hit the balanced/normal switch, to balanced, I lose
about 50% of the right hand volume. (I don't use balanced 'phones or cables btw)
 
If I switch it back, the problem remains. However if I switch it lots and lots of
times quickly the right channel comes back, most of the time.
 
I tried an external amp via the line out and the issue was confirmed, using line out it was perfectly balanced in both channels.
I took out the mini box, replaced it, then switched back to standard amp card 
(not a lot of difference btw) and the problem came back, and stays using headphone output.
 
If the switch is set to balanced and I am using normal headphones,in  this case
T70P, what should I hear? or what do you hear?
 
Anyone else experienced this at all? or is it a send back to China job?

 
I experienced this issue some time ago - along with several other hardware issues that took multiple replacement units to finally resolve.  The good thing is Hifiman support in the US replaced my 901 each time without question until I finally received a unit that has been problem free.  I wouldn't mess around - I would get a new unit if it's still under warranty.

 

[KT66]

Update, thanks to earlier poster who said to put headphones in first , then turn on, that seems to work
MANY thanks

Sometimes Chinese DAPs remind me of running an old classic car!

 

[nedaroth]

Just a quick note on amps, my setup  HM-901, Vorz Pure II , Shure SE 845, with standard amp card removed. beta firmware 2002 i had the shutdown with using artist with firmware2001 but the beta fixed that.  First I want to say the standard amp has no issue with volume at all and should satisfy most anyone. The Pure II took it to the next level, I would not have shopped for an external amp as I believe one is not needed but I had the Pure II collecting dust and just wanted to a-b it with stock amp. Not a technical review just a I love my HM-901

 

[jamato8]

  Just a quick note on amps, my setup  HM-901, Vorz Pure II , Shure SE 845, with standard amp card removed. beta firmware 2002 i had the shutdown with using artist with firmware2001 but the beta fixed that.  First I want to say the standard amp has no issue with volume at all and should satisfy most anyone. The Pure II took it to the next level, I would not have shopped for an external amp as I believe one is not needed but I had the Pure II collecting dust and just wanted to a-b it with stock amp. Not a technical review just a I love my HM-901

Do you have the one card for the 901 or have you tried other cards to compare to the external amp?

 

[nedaroth]

I have just the one card, if I did not have the pure II amp I would have been happy with the standard one that came with the 901.

 

[Valuephile]

Just a quick note on amps, my setup  HM-901, Vorz Pure II , Shure SE 845, with standard amp card removed. beta firmware 2002 i had the shutdown with using artist with firmware2001 but the beta fixed that.  First I want to say the standard amp has no issue with volume at all and should satisfy most anyone. The Pure II took it to the next level, I would not have shopped for an external amp as I believe one is not needed but I had the Pure II collecting dust and just wanted to a-b it with stock amp. Not a technical review just a I love my HM-901

I also use the vorz pure II with my 901 and find it to be an extraordinary match. With the amp card removed from my 901 I get approximately 8-10 hours of battery life vs the 4-6 hours I was getting with an amp card installed. The pure II lasts about 10 hours as well so I just charge both at the same time when I run out of battery juice. In addition, I get continuous volume control for my very sensitive Roxannes vs the stepped too loud or too soft approach the 901 uses. Last but not least, with the 901 and pure II pairing the sound quality is just fantastic IMO.
On another note, can you direct me as to how you downloaded beta firmware 2.002? I can't figure out how to do it and I'd really like the gapless feature to work again.
Cheers.

 

[KT66]

When is official 2.002 out ?

 

[jamato8]

When is official 2.002 out ?

As far as I know, it is still the 2.002 beta. I downloaded it from a Chinese site and have not had any issues but I know that many prefer to wait for the official release. 

 

[nedaroth]

Valuephile Here is the link for beta 2002
 
http://bbs.hifiman.cn/forum.php?mod=viewthread&tid=9054&mobile=2

 

[KT66]

Thanks for the links and info, from what I see there is no improvement to audio, just functionality,
which I am fine with at 2.001 - 
 
I wish firmware could fix the balanced/normal balance issue.
 
The look people give me on the train when I have to flick the balanced/normal switch 20 times to 
get a central image is hilarious.

 

[jamato8]

  Thanks for the links and info, from what I see there is no improvement to audio, just functionality,
which I am fine with at 2.001 - 
 
I wish firmware could fix the balanced/normal balance issue.
 
The look people give me on the train when I have to flick the balanced/normal switch 20 times to 
get a central image is hilarious.

Well maybe they will give you more room. :T)