[LarsHP]

  Thanks these cables look great!
 
Still a bit confused with the balanced cable variables though.
 
So if you have a TRRS fitted to one of these double helix cables, does that offer any benefit as the HD650 still remains an unbalanced headphone.
 
So if that is the case, does the TRRS plug make the Double helix cable a balanced cable suitable for balanced mode on the HM901 or will I get the same kind of performance from a normal "Unbalanced" cable such as the Moon Audio Silver Dragon V3? which really does sound like a worthy investment.

Any headphone can be driven balanced as long as you can access the two connectors on each driver. You then just need four conductors/cables to the plug. Unbalanced cables has four conductors to the Y-split where the two ground conductors are soldered into one.

 

[burtomr]

  Unbalanced cables has four conductors to the Y-split where the two ground conductors are soldered into one.

 
Hmmm, in my experience the typical aftermarket cable has the required 4 wires all the way to the plug where the grounds are joined at the plug not the 'Y'. This configuration is ideal for conversion to balanced with only the swapping of the (3) pole plug to a (4) pole plug like TRRS or Kobiconn

 

[LarsHP]

  Hmmm, in my experience the typical aftermarket cable has the required 4 wires all the way to the plug where the grounds are joined at the plug not the 'Y'. This configuration is ideal for conversion to balanced with only the swapping of the (3) pole plug to a (4) pole plug like TRRS or Kobiconn

I was referring to unbalanced cables. If there are four wires, the cable is in fact balanced, but the plug might not be a balancded one. Stock cables, however, often has three wires only from the Y-split AFAIK.

 

[burtomr]

  Stock cables, however, often has three wires only from the Y-split AFAIK.

 
True for stock cables > only 3 wires @ plug.

 

[KillerX]

Hi folks,
 
its me again! The one who got the HM901 standard amp card frying my RE600. I would like to post some updates as well as some history on some issues regarding the HM901. 
 
Firstly, i ordered the HM 901 about 1+ month back and the RE600 one week later.  Upon receiving both, i tried both out and it worked ok for about a week or so although i already noticed the problem of the player getting very warm as well as the player being restarted randomly. I formatted the SD card to ex-fat format, removed all unnecessary files on the sd card.  I used it lightly as i was bogged down with work. Then just one fine evening on a weekend, while playing my first song on the HM 901, the left side of the RE600 became extremely hot and i threw it on the table while still getting warmer. I yanked out the cable from the jack and switched off the player hurriedly. The player was very warm as well. As a result of the earphone, there was pain in my ears and it rang for quite a while in my left ear. I allowed the player to cool down and when i tried it again, the RE600 did not have any output from the left side of the earphones. When i tried out IEM and headphones on the HM 901, there was a very loud magnetic interference sound and the left side of the earphones was also muted. In frustration, I emailed to the respective agencies for an explanation and for a solution. I also posted this on headfi if you folks remember and i got several kind members offering me tips to determine the source of the problem which ended up being the standard amp card.  The following day, Dr Fang called me (i reside in Singapore and i appreciate his gesture), asked for my health status and offered to ship the standard amp card as well as a new RE600 free of charge. I did not need to ship back the card.
 
 
A few days later, i received the new card. In the midst of waiting, i did not use the HM 901 at all. I noticed that the balanced card seemed to be a bit bigger than the standard amp card and it was harder to remove than the standard card. i needed to use something to pry out (although lightly) the card from the groove. I used it for awhile on the day for testing purposes and it was good, sound was apparently okay. As i continued using it, i found that the battery life on the HM901 got really bad. Finally, the player started dying on me after 4-5 songs. I could only get the player back on after charging it for a while. (removing the battery or using the reset button did not work) I got in contact with the respective company again to consult them and they suggested some ideas to determine the problem. Initially, i thought that the standard amp card might have previously fried the battery but when i tried going direct with the charger with the battery removed, the player died after one song. I used multiple sd cards to see if songs or the sd card was the problem but the same problem persisted. Finally, they sent me a new unit with the charger and all other accessories without a new card which i received this morning. Problem solved...right? Let's read on...
 
 
 
As usual, i put in the balanced amp card and the sd card. I paired it first with the westone 4R. When i switched it on, i immediately heard the dreaded magnetic interference noise playing as the sd card was reading. I flicked the switch to a normal output and i could hear distinctly that the left side of the earphone being muffled while the right side was okay. The noise was gone but i suspect that the muffling was caused by this interference. I paused the song to try another earphone. While i was pulling out the jack to try another earphone, the magnetic interference noise went away when the earphone jack was left halfway out of the port. The sound however when i played the song again was only half full (not that i would like it be left this way if the sound was okay). I changed to the RE600, same problem just that this time, when i switched it to balanced mode, the sound was fuller than the 4R. My earphones are both working fine as i tested them again on my handphone and on my DAC at home. This time round, i really do not know what has happened as the balanced card is still barely a month old, the player is new, i did not charge when i use it so it couldn't have been a fuse, happens on all my sd cards, happens on all my headphones and earphones, happens when i connect it to my speakers. If **** does happen from time to time, i really got a ****load of it continuously this time. Really Hifiman, even on a new player? Why me, i wonder....
 
 
I got very upset with what happened and after trying a series of things, i decided to email the company again. This was what i had to say...

QUOTE
 
I've just received the new HM901 today in the morning. Popped in the balanced card and tried playing it with a 128gb sdcard. I hear a very distinct magnetic interference sound which sounds like this running in the background. 

http://www.youtube.com/watch?v=ctzl2rNeRd8

When music plays the interference is gone, however one side of the earphone is distinctly softer than the other when i use my Westone 4R. I paused the track and when i insert half the jack into the port, the sound of the magnetic interference is gone. It is only when i insert the earphone jack into the port fully that this magnetic interference occurs.  When i adjust the setting from balanced to normal, one side of the player completely goes half-mute. The jack though needs to be adjusted quite a fair bit to achieve a good sound. When i use the RE600 with the player, the magnetic interference sound is still there but the sound when playing songs is fuller. However when i adjust it at about 5 on the volume dial, the sound begins to crack. I also realize that all my mp3s seem to display 16bit 44khz on the player when some mp3s are more than that. I tried  the following to see if it helped to remove the magnetic interference, 
 
1) changing sd cards 
2) charging the device
3) using different earphones and headphones
4) restart the HM901 a few times
5) removed the battery, clean the contact point
6) removed the card and reinserted again. 
4) let the mp3 scan for all the songs first before playing (BUT after letting it scan (took about an hour or so) completely, when it restarted, the process of scanning started AGAIN -_-'')
 
All of which did not work! I would have loved to try using a different type of card for it unfortunately i only have the balanced one for now and am unable to ascertain again if the card is the one giving all the problems.  On a sidenote though, the battery issue seem to be over for now. AND also, the balanced amp card seem to be harder to remove than the standard card.  On the standard card, i just have to push down the eject button on the side and slightly lift the card using the groove to remove it. The balanced card that was sent to me seem to be bigger and i have to use something to lightly pry the card out of the slot. Is this normal?
 
I really am getting very frustrated at all this problems that i am facing. Even when it comes out of the box, these issues are happening. Can this be mail be forwarded to Dr Fang to let him know about this? I don't want the same situation that fried the first RE600 and almost put me to a doctor to happen again as these signs the player are showing me is alarming to say the least. 
 
UNQUOTE
 
 
I really wonder do you guys experience ANY of the following which i have experienced. What would you have done if you were in my shoes. Most of you would agree that Its a very costly investment and i don't think anyone should be subject to such treatment. I am not someone who earns alot of money and i saved long and hard for purchasing this. All i really wanted was to have some intimate sessions with songs and chill out after a long day at work. Instead, i return home to find myself getting all worked up over this. As previously mentioned, i do not live in the states and it is an incredible hassle to do the shipping back and forth. I really appreciate hifiman for doing what they have done so far in trying to rectify the issue but there seems to be far too many things plaguing what could be a potentially fantastic music source, from hardware to software. There's no use in having the best Sabre ESS ES9018 chips. If these issues are not solved within the month or so, i would really send everything that was sent to me back to hifiman and demand for a refund. I'm also sure they do not want a customer like me whereby they have to keep sending replacements at their own loss. I also do not want to appear to be some sort of a scammer despite the massive trust they have shown. 
 
Sorry for this long post but i just had to get this out of my chest. Again, this post is not intended to put off anyone who has had great experiences with this player ( i envy you ) and long may it continue for you. I just wanted to find out if anyone else who might have been getting these issues but managed to get it rectified or find out about their after actions.
 
Thank you to all and have a good evening. 

 

[tphillips63]

I have had similar but not as bad issues with my balanced card.
I noticed there is a plastic flange retaining tab on the top of amp cards just opposite the bottom metal retaining connector.  Orientated with the amp card ziff connector to your right as looking down on the unit.
 
This top plastic tab pushes the balanced card just a tiny bit out of alignment with the ziff socket and I think is causing these issues.
Inserted, reinserted, the balanced amp card many times and used a plastic spudger to move it into better position.  Once it is more square in the ziff socket it works fine.  My 901 later fell off the arm of the couch onto the cushion, just a few inches, and the balanced card was out of position and channels were reversed and or no sound out of one channel.  I powered it off, reseated the card, and it was back sounding great again.This is an issue if at least three of us are having the problem. 
All with brand new, in my case less than two weeks of ownership for all the parts, HM-901, Standard and balanced amp cards, RE-600 for me.
 
I do not want to get rid of mine, nor do I want to be without it for a long period of time.  Rather I would like HiFiMan to develop a better fit, card design or whatever it takes so the HM-901 can be reliably used in balanced mode.  

I thought it sounded great with the standard amp card, but after using the balanced amp card the difference is so much better that you would not want to revert back to standard amp card either.

 

[glockhit]

  I have had similar but not as bad issues with my balanced card.
I noticed there is a plastic flange retaining tab on the top of amp cards just opposite the bottom metal retaining connector.  Orientated with the amp card ziff connector to your right as looking down on the unit.
 
This top plastic tab pushes the balanced card just a tiny bit out of alignment with the ziff socket and I think is causing these issues.
Inserted, reinserted, the balanced amp card many times and used a plastic spudger to move it into better position.  Once it is more square in the ziff socket it works fine.  My 901 later fell off the arm of the couch onto the cushion, just a few inches, and the balanced card was out of position and channels were reversed and or no sound out of one channel.  I powered it off, reseated the card, and it was back sounding great again.This is an issue if at least three of us are having the problem. 
All with brand new, in my case less than two weeks of ownership for all the parts, HM-901, Standard and balanced amp cards, RE-600 for me.
 
I do not want to get rid of mine, nor do I want to be without it for a long period of time.  Rather I would like HiFiMan to develop a better fit, card design or whatever it takes so the HM-901 can be reliably used in balanced mode.  

I thought it sounded great with the standard amp card, but after using the balanced amp card the difference is so much better that you would not want to revert back to standard amp card either.

 
Please see my post (several) in the other HM901 forum. The channels would reverse after the player warmed up..approx 1 hr or so. Also I could never get the back cover to  lock when the balanced card was installed. Not a problem with the stock card installed. Also many other issues. After quite a lot of frustration and no solution from tech support (that made sense) I returned everything for a refund. I don't believe the HM901 is ready for the consumer market yet. Way to many issues.
I enjoyed my HM801.
I'm moving on to another manufacture.Very disappointed. 

 

[glockhit]

  Hi folks,
 
its me again! The one who got the HM901 standard amp card frying my RE600. I would like to post some updates as well as some history on some issues regarding the HM901. 
 
Firstly, i ordered the HM 901 about 1+ month back and the RE600 one week later.  Upon receiving both, i tried both out and it worked ok for about a week or so although i already noticed the problem of the player getting very warm as well as the player being restarted randomly. I formatted the SD card to ex-fat format, removed all unnecessary files on the sd card.  I used it lightly as i was bogged down with work. Then just one fine evening on a weekend, while playing my first song on the HM 901, the left side of the RE600 became extremely hot and i threw it on the table while still getting warmer. I yanked out the cable from the jack and switched off the player hurriedly. The player was very warm as well. As a result of the earphone, there was pain in my ears and it rang for quite a while in my left ear. I allowed the player to cool down and when i tried it again, the RE600 did not have any output from the left side of the earphones. When i tried out IEM and headphones on the HM 901, there was a very loud magnetic interference sound and the left side of the earphones was also muted. In frustration, I emailed to the respective agencies for an explanation and for a solution. I also posted this on headfi if you folks remember and i got several kind members offering me tips to determine the source of the problem which ended up being the standard amp card.  The following day, Dr Fang called me (i reside in Singapore and i appreciate his gesture), asked for my health status and offered to ship the standard amp card as well as a new RE600 free of charge. I did not need to ship back the card.
 
 
A few days later, i received the new card. In the midst of waiting, i did not use the HM 901 at all. I noticed that the balanced card seemed to be a bit bigger than the standard amp card and it was harder to remove than the standard card. i needed to use something to pry out (although lightly) the card from the groove. I used it for awhile on the day for testing purposes and it was good, sound was apparently okay. As i continued using it, i found that the battery life on the HM901 got really bad. Finally, the player started dying on me after 4-5 songs. I could only get the player back on after charging it for a while. (removing the battery or using the reset button did not work) I got in contact with the respective company again to consult them and they suggested some ideas to determine the problem. Initially, i thought that the standard amp card might have previously fried the battery but when i tried going direct with the charger with the battery removed, the player died after one song. I used multiple sd cards to see if songs or the sd card was the problem but the same problem persisted. Finally, they sent me a new unit with the charger and all other accessories without a new card which i received this morning. Problem solved...right? Let's read on...
 
 
 
As usual, i put in the balanced amp card and the sd card. I paired it first with the westone 4R. When i switched it on, i immediately heard the dreaded magnetic interference noise playing as the sd card was reading. I flicked the switch to a normal output and i could hear distinctly that the left side of the earphone being muffled while the right side was okay. The noise was gone but i suspect that the muffling was caused by this interference. I paused the song to try another earphone. While i was pulling out the jack to try another earphone, the magnetic interference noise went away when the earphone jack was left halfway out of the port. The sound however when i played the song again was only half full (not that i would like it be left this way if the sound was okay). I changed to the RE600, same problem just that this time, when i switched it to balanced mode, the sound was fuller than the 4R. My earphones are both working fine as i tested them again on my handphone and on my DAC at home. This time round, i really do not know what has happened as the balanced card is still barely a month old, the player is new, i did not charge when i use it so it couldn't have been a fuse, happens on all my sd cards, happens on all my headphones and earphones, happens when i connect it to my speakers. If **** does happen from time to time, i really got a ****load of it continuously this time. Really Hifiman, even on a new player? Why me, i wonder....
 
 
I got very upset with what happened and after trying a series of things, i decided to email the company again. This was what i had to say...

QUOTE
 
I've just received the new HM901 today in the morning. Popped in the balanced card and tried playing it with a 128gb sdcard. I hear a very distinct magnetic interference sound which sounds like this running in the background. 

http://www.youtube.com/watch?v=ctzl2rNeRd8

When music plays the interference is gone, however one side of the earphone is distinctly softer than the other when i use my Westone 4R. I paused the track and when i insert half the jack into the port, the sound of the magnetic interference is gone. It is only when i insert the earphone jack into the port fully that this magnetic interference occurs.  When i adjust the setting from balanced to normal, one side of the player completely goes half-mute. The jack though needs to be adjusted quite a fair bit to achieve a good sound. When i use the RE600 with the player, the magnetic interference sound is still there but the sound when playing songs is fuller. However when i adjust it at about 5 on the volume dial, the sound begins to crack. I also realize that all my mp3s seem to display 16bit 44khz on the player when some mp3s are more than that. I tried  the following to see if it helped to remove the magnetic interference, 
 
1) changing sd cards 
2) charging the device
3) using different earphones and headphones
4) restart the HM901 a few times
5) removed the battery, clean the contact point
6) removed the card and reinserted again. 
4) let the mp3 scan for all the songs first before playing (BUT after letting it scan (took about an hour or so) completely, when it restarted, the process of scanning started AGAIN -_-'')
 
All of which did not work! I would have loved to try using a different type of card for it unfortunately i only have the balanced one for now and am unable to ascertain again if the card is the one giving all the problems.  On a sidenote though, the battery issue seem to be over for now. AND also, the balanced amp card seem to be harder to remove than the standard card.  On the standard card, i just have to push down the eject button on the side and slightly lift the card using the groove to remove it. The balanced card that was sent to me seem to be bigger and i have to use something to lightly pry the card out of the slot. Is this normal?
 
I really am getting very frustrated at all this problems that i am facing. Even when it comes out of the box, these issues are happening. Can this be mail be forwarded to Dr Fang to let him know about this? I don't want the same situation that fried the first RE600 and almost put me to a doctor to happen again as these signs the player are showing me is alarming to say the least. 
 
UNQUOTE
 
 
I really wonder do you guys experience ANY of the following which i have experienced. What would you have done if you were in my shoes. Most of you would agree that Its a very costly investment and i don't think anyone should be subject to such treatment. I am not someone who earns alot of money and i saved long and hard for purchasing this. All i really wanted was to have some intimate sessions with songs and chill out after a long day at work. Instead, i return home to find myself getting all worked up over this. As previously mentioned, i do not live in the states and it is an incredible hassle to do the shipping back and forth. I really appreciate hifiman for doing what they have done so far in trying to rectify the issue but there seems to be far too many things plaguing what could be a potentially fantastic music source, from hardware to software. There's no use in having the best Sabre ESS ES9018 chips. If these issues are not solved within the month or so, i would really send everything that was sent to me back to hifiman and demand for a refund. I'm also sure they do not want a customer like me whereby they have to keep sending replacements at their own loss. I also do not want to appear to be some sort of a scammer despite the massive trust they have shown. 
 
Sorry for this long post but i just had to get this out of my chest. Again, this post is not intended to put off anyone who has had great experiences with this player ( i envy you ) and long may it continue for you. I just wanted to find out if anyone else who might have been getting these issues but managed to get it rectified or find out about their after actions.
 
Thank you to all and have a good evening. 

 
That's terrible. When the HM901 works properly it is truly addictive. Amazing sound..that is when it works. To much money for a product that has so many hardware and software problems. 
Please see my post (several) in the other HM901 forum. The channels would reverse after the player warmed up..approx 1 hr or so. Also I could never get the back cover to  lock when the balanced card was installed. Not a problem with the stock card installed. Also many other issues. After quite a lot of frustration and no solution from tech support (that made sense) I returned everything for a refund. I don't believe the HM901 is ready for the consumer market yet. Way to many issues.
I'm moving on to another manufacture.Very disappointed. I wish you luck. I'm fed up. I didn't purchase this to be a beta tester at my expense.

 

[KillerX]

  I have had similar but not as bad issues with my balanced card.
I noticed there is a plastic flange retaining tab on the top of amp cards just opposite the bottom metal retaining connector.  Orientated with the amp card ziff connector to your right as looking down on the unit.
 
This top plastic tab pushes the balanced card just a tiny bit out of alignment with the ziff socket and I think is causing these issues.
Inserted, reinserted, the balanced amp card many times and used a plastic spudger to move it into better position.  Once it is more square in the ziff socket it works fine.  My 901 later fell off the arm of the couch onto the cushion, just a few inches, and the balanced card was out of position and channels were reversed and or no sound out of one channel.  I powered it off, reseated the card, and it was back sounding great again.This is an issue if at least three of us are having the problem. 
All with brand new, in my case less than two weeks of ownership for all the parts, HM-901, Standard and balanced amp cards, RE-600 for me.
 
I do not want to get rid of mine, nor do I want to be without it for a long period of time.  Rather I would like HiFiMan to develop a better fit, card design or whatever it takes so the HM-901 can be reliably used in balanced mode.  

I thought it sounded great with the standard amp card, but after using the balanced amp card the difference is so much better that you would not want to revert back to standard amp card either.

 
 
I just tried re-seat the card and guess what? Now when i switch the player on, it tells me "Battery Empty" and shuts off immediately despite showing a full bar on the indicator. There is now also a SUPER LOUD buzzing sound when it turns on! This new player that they sent me poses more problems than the original.

 

[zenpunk]

My balanced card fit nicely. I hope you are using the right one and not the one made for the HM-801?  

 Or are they the same?
No issue with mine except for the sluggish, buggy and terribly ugly firmware/UI...
well I had a couple of unexpected shutdown/restart.
Does anybody know how many firmware updates the 801 had and how fast they came?

 

[CosmicHolyGhost]

@KillerX
 
Your experience is really awful and I am really sorry to her that (2nd time still a faulty unit, just crazy...)... I hope you get your refund and compensation soonest... spend the money on other brands... it is only music after all..all the best!

 

[KillerX]

As a last resort, i have tried putting the new unit HM901's battery onto my previous unit of HM901 with the same balanced amp card. I'm into my second song so far and so far there is no magnetic interference noise nor buzzing sound. Songs are running fine and splendid. Now i can only hope and pray that the 5-6 song shut down battery drain issue doesn't happen. Will monitor and update. 
 
UPDATE:-
Running on the 9th song now and no sign of the battery drain that was present previously. Will try listening for another 1/2 hour or so and update again. I have this feeling is a problem with the 2 chargers that were given to me. Problem now is if the battery goes dead i wonder how i should charge it and which charger i should use. (afraid that either would kill off the only working player i have now or battery)

 

[LarsHP]

I just tried re-seat the card and guess what? Now when i switch the player on, it tells me "Battery Empty" and shuts off immediately despite showing a full bar on the indicator. There is now also a SUPER LOUD buzzing sound when it turns on! This new player that they sent me poses more problems than the original.

Try reinstalling the amp card and see what happens ...

 

[bartsimpson6994]

What a great read and a great post . It made my experiance in the UK with the HM901 as nothing to complain about.
 
Seven days ago my 901 arrived complete with the IEM card. I ordered it from Moon Audio as you cannot buy them in th UK
 
Drew the owner of the business  said there was a problem with standard card and they would send the IEM instead free of charge.
When the player arrived I swithced it on and it just stuck on the start screen and would not boot up. I pressed the reset and thats all it did and just hung on the start logo again. I removed the battery and IEM card and it still hung on the start screen.
 
I was just about to fire an email off to Moon Audio when I had the idea to reinstall the firmware from the website and the player fired into life to my surprise and it played my Flac files with amazing sound quality better than anything I had heard before.
 
I then tried to load some AAC files from itunes and they just would not play . I contacted HIFIMAN and they sent me another beta firmware and the AAC files playes Yippee.  The next day the AAC  would not play so I reinstalled the firware and they played again.
 
Two days later same again the AAC files would not play so I reinstalled the software and well I think you get the message the AAC files will play for 2 days and no more.
 
 
I emailed HIFIMAN and they said its a firmware issue and not a player issue. However they did offer an exchange. They said that they would talk to the engineer and then get back to me which I don't mind as I wanted to keep the player . Apart from that I paid £98.00
inport tax and did not want a repeat of that bill.
 
The player sound is the best DAP I have owned but I have to question HIFIMAN quality control especially at the final testing stage
do they actually play the DAP or just plug it into a machine and look at a graph.
 
The player does sometimes skip songs but that appears to be common .
 
I am waiting for HIFIMAN to come back to me - but is anyone else  have any problems with the 901?????
 
Charles Hayes

 

[Jwm48324]

I have not had any problems with my 901 and balanced card since day one. Isn't there anyone else who's unit is working great. I would like to get a count on the working units.