[kkcc]

Quote:

 
Just reminiscing about old posts on this thread, it is hard to believe that the HM901 was actually supposed to be released in May of 2012 as the post above from April of 2012 says!  More than a year after that deadline and the HM901 is still not available in the US!!!!

 
Yes it had been a long wait... so long that I actually lost interest once DX100 came out!  I purchased the HM901 largely just to satisfy my curiosity after the long long wait and not really expecting to keep it.  Well this has now changed and it's definitely a keeper (sans the standard amp board which is of no use to me).

 

[LarsHP]

This really is not a surprise to me - both that it was worth waiting for and that the standard amp module is good, but not as good as the optional amp board(s). This last thing is of course not something I am happy about, because it makes the HM-901 more expensive to get the full sound quality it is capable of and the stanard module expendable and actually making the total package more costly than necessary.
 
I would have prefered the HM-901 standard amp to be the (upcoming) IEM amp module - even if it made it a little more expensive, because as it is, the standard module will be useless for the target consumer: those who want the best possible sound from a one box solution / DAP. I might just get the balanced card and skip the IEM card, if the 901 with balanced card has enough dial on the volume to be used with sensitive IEMs. (I already have been confirmed that the Balanced module has less than 1 Ohm in output impedance.)
 
How are you guys experiencing the balanced module with sensitive IEMs in terms of getting the right volume at low or medium-to-low levels?

 

[pekingduck]

It's mostly adequate but I really wish it had more steps for finer adjustment. If I remember correctly there are like 20-something steps.
 
You can now buy the HM901 in China without the standard amp module. Perhaps they will do the same for international release.

 

[Mimouille]

Quote:

It's mostly adequate but I really wish it had more steps for finer adjustment. If I remember correctly there are like 20-something steps.
 
You can now buy the HM901 in China without the standard amp module. Perhaps they will do the same for international release.

Apart from Taobao, any shops have it physically in Shanghai for instance ? I have heard of one but it is faaaaaaar.

 

[pekingduck]

PM sent.
Quote:

Apart from Taobao, any shops have it physically in Shanghai for instance ? I have heard of one but it is faaaaaaar.

 

[kkcc]

This really is not a surprise to me - both that it was worth waiting for and that the standard amp module is good, but not as good as the optional amp board(s). This last thing is of course not something I am happy about, because it makes the HM-901 more expensive to get the full sound quality it is capable of and the stanard module expendable and actually making the total package more costly than necessary.

I would have prefered the HM-901 standard amp to be the (upcoming) IEM amp module - even if it made it a little more expensive, because as it is, the standard module will be useless for the target consumer: those who want the best possible sound from a one box solution / DAP. I might just get the balanced card and skip the IEM card, if the 901 with balanced card has enough dial on the volume to be used with sensitive IEMs. (I already have been confirmed that the Balanced module has less than 1 Ohm in output impedance.)

How are you guys experiencing the balanced module with sensitive IEMs in terms of getting the right volume at low or medium-to-low levels?

To get the best sound from the balanced board you'd need to also re-terminate your cable with TRRS 3.5mm plugs. FT 334 and xba4 are some of the most sensitive IEMs and I got mixed results - 334 good, xba4 not so. I tend to use high-gain volume 2 with the 334 for most music except very quiet ones - background is not pitch black on high gain.

Volume adjustment could use more steps but guess I'm spoiled by the AK with their ability to really fine tune.It only has 20 usable steps - you will get channel imbalance in between the steps more often than not.

Skip the stock card unless your primary iem is either k3003 or IE800.

 

[LarsHP]

Quote:

To get the best sound from the balanced board you'd need to also re-terminate your cable with TRRS 3.5mm plugs. FT 334 and xba4 are some of the most sensitive IEMs and I got mixed results - 334 good, xba4 not so. I tend to use high-gain volume 2 with the 334 for most music except very quiet ones - background is not pitch black on high gain.

Volume adjustment could use more steps but guess I'm spoiled by the AK with their ability to really fine tune.It only has 20 usable steps - you will get channel imbalance in between the steps more often than not.

Skip the stock card unless your primary iem is either k3003 or IE800.

What???? Channel imbalance?
 
"in between": Is this when one of the steps isn't properly selected?
- Or is it actual channel imbalance? (which means that there is a difference between the two resistors for that position)
 
Thanks for your answers - also thanks to pekingduck.

 

[kkcc]

Quote:

What???? Channel imbalance?
 
"in between": Is this when one of the steps isn't properly selected?
- Or is it actual channel imbalance? (which means that there is a difference between the two resistors for that position)
 
Thanks for your answers - also thanks to pekingduck.

 
On the POT there are major markings of 0 to 10 with five minor markings between every digits.  But the wheel actually only clicks at values of 0, 0.5, 1, 1.5, 2, 2.5.... etc.  Whenever you try to turn it to somewhere between 2 to 2.5, where there is no click step, you'd need to very precisely aligned to the minor markings or else L/R volume are not matched.  This make fine-tuning the volume between the clicking points a hassle.  I was under the impression the POT would provide a continuous adjustment and not in steps/intervals.

 

[goodvibes]

That was my impression but I was corrected by someone saying it's new miniature discrete attenuator and not continuous. If that's the case, there is no in between adjustment.

 

[LarsHP]

It's not a POT, but a stepped attenuator and thus should (only) be in  ... welll ... steps. I am frankly surprised that you can get anything right between the steps.
It is supposed to be 23 steps plus two gain levels - that's it. The 0, 0.5, 1, 1.5 etc. up to 10, is most likely making these 23 steps.
 
So, if you find a position between two clicks / steps, then you are probably using both steps at the same time with more or less contact on either side/resistor. In other words you are trying to make the attenuator do something it isn't supposed to do ... if you get the picture.

 

[Mython]

For those of you concerned about heat-dissipation and battery life on the 901, the following DAC chip may be a game-changer for ES9018 fans, in the near future:
 
http://www.head-fi.org/t/661411/fiio-x5-thread-info-updated-on-6-24-13-in-1st-post/720#post_9564054
 
 
I do appreciate that the amp stage will still suck plenty of juice and make plenty of heat, but every saving is helpful.

 

[kkcc]

It's not a POT, but a stepped attenuator and thus should (only) be in  ... welll ... steps. I am frankly surprised that you can get anything right between the steps.
It is supposed to be 23 steps plus two gain levels - that's it. The 0, 0.5, 1, 1.5 etc. up to 10, is most likely making these 23 steps.

So, if you find a position between two clicks / steps, then you are probably using both steps at the same time with more or less contact on either side/resistor. In other words you are trying to make the attenuator do something it isn't supposed to do ... if you get the picture.

Yes that make sense.I recall seeing debate in whether it is a stepped attenuator or a potentiometer but it sure behaved like stepped.


Just received more goodies for the 901:

 

[LarsHP]

When you use your sensitive IEMs with the balanced amp, what steps on the volume dial do you then use? From 1 to 2.5 or?

 

[kkcc]

Quote:

When you use your sensitive IEMs with the balanced amp, what steps on the volume dial do you then use? From 1 to 2.5 or?

 
For 334 mainly using 2, max 2.5 on high gain.   Tho I'm told I'm a low volume listener.  For reference I normally use 35 for 334 on AK120, 40 for RE400/W4R, and 45 for ER4S.

 

[LarsHP]

Thanks. It seems like there is room for volume adjustment even with the balanced amp and sensitive IEMs. Jippie!