[glockhit]

The amp appears to be inserted tightly.
I did check to make sure the plug was terminated correctly. It was.Also no loose connections.
I have been using a SDXC 64GB flash card.
Just removed it and replaced it with my formatted 32fat 8GB SDHC card. I have been playing music for three hours with no channel reverse.Generally it reverses channels in about an hour.
Could a card have anything to do with this issue and if yes..why? Thanks.

 

[AnakChan]

The amp appears to be inserted tightly.
I did check to make sure the plug was terminated correctly. It was.Also no lose connections.
I have been using a SDXC 64GB flash card.
Just removed it and replaced it with my formatted 32fat 8GB SDHC card. I have been playing music for three hours with no channel reverse.Generally it reverses channels in about an hour.
Could a card have anything to do with this issue and if yes..why? Thanks.

 
Amp module - check!
 
I actually didn't mean loose connectors. In my iPhone compatible headphone which uses TRRS 3.5mm, I actually have to pull the plug out a tad to actually get a proper connection (of the TRS socket). I don't know if you have the same problem but heck, it's a free test, so why not give it a shot.
 
SDCard causing the channel flip? For the life of me I can't imagine how that could cause it.
 
This channel reversal after 1 hr, presumably doesn't matter what music/track/album track you're listening to? If so, then I'm wondering if heat is causing some soldering connection to get loose.

 

[glockhit]

   
Amp module - check!
 
I actually didn't mean loose connectors. In my iPhone compatible headphone which uses TRRS 3.5mm, I actually have to pull the plug out a tad to actually get a proper connection (of the TRS socket). I don't know if you have the same problem but heck, it's a free test, so why not give it a shot.
 
SDCard causing the channel flip? For the life of me I can't imagine how that could cause it.
 
This channel reversal after 1 hr, presumably doesn't matter what music/track/album track you're listening to? If so, then I'm wondering if heat is causing some soldering connection to get loose.

 
I'll give the plug connection a try. Your right it would be great if it was something that simple.The battery just died. When it's charged I will give it a try. In terms of the card being an issue I don't know how/why that could cause this to happen. Maybe a coincidence. It's strange that after an hour it has been reversing the channels consistently for days. When I put this card in four hours went by without a problem. I will try it again when it's finished charging. Thanks

 

[glockhit]

Still having the same reverse channel issue. I'm done trying to figure it out. The player is defective. I will return the HM901 and the balanced amp Monday to Headirect. Hopefully the replacement will be alright.

 

[AnakChan]

Still having the same reverse channel issue. I'm done trying to figure it out. The player is defective. I will return the HM901 and the balanced amp Monday to Headirect. Hopefully the replacement will be alright.

Fair enough. Good luck in your replacement. Would be interesting if you could get them to tell you the root cause of the issue when they replace it.

 

[glockhit]

Thank you. I'll report back with their findings.Regards.

 

[rdsreference]

Has anybody had a similar experience to me. Received my free balanced card on Friday, along with the upgraded cable from Moon Audio which is very good. I tested it on a few devices before plugging into the 901, stock cable v blue Dragon certainly not as peaky with smoother mids, anyway to the point, My unit certainly sounds better with the balanced card but still not fantastic by any means I'm still wondering if this unit is faulty anyone have a similar issue when they received their replacement card it's much better but still not 100%. Some say it needs a long long time to burn in much longer that other daps, I can hear faint nuances of detail trying to come through in the background let's hope this will continue to happen and give level of transparency I expect at this level.

 

[zachchen1996]

Has anybody had a similar experience to me. Received my free balanced card on Friday, along with the upgraded cable from Moon Audio which is very good. I tested it on a few devices before plugging into the 901, stock cable v blue Dragon certainly not as peaky with smoother mids, anyway to the point, My unit certainly sounds better with the balanced card but still not fantastic by any means I'm still wondering if this unit is faulty anyone have a similar issue when they received their replacement card it's much better but still not 100%. Some say it needs a long long time to burn in much longer that other daps, I can hear faint nuances of detail trying to come through in the background let's hope this will continue to happen and give level of transparency I expect at this level.

 
what iems are you using with it? Because low end iems might be holding the 901 back.

 

[rdsreference]

Using a pair of HD 600,S With moon audio blue dragon v3 headphone cable. All my music is from hd tracks plus some dsd I purchased direct from the website, other tracks all in flac are cd rips using eac which I did myself it's getting marginally better but it's taking a very long time to improve perhaps I'll just have to be patient

 

[zachchen1996]

Using a pair of HD 600,S With moon audio blue dragon v3 headphone cable. All my music is from hd tracks plus some dsd I purchased direct from the website, other tracks all in flac are cd rips using eac which I did myself it's getting marginally better but it's taking a very long time to improve perhaps I'll just have to be patient

 
I think perhaps 901 is best used with iems, full size headphones might be a bit too hard to drive with enough authority. I loved my he400s with the 901, but I felt the balanced amp lacked sufficient oomph to bring complete control over the 400s bass. Maybe get some totl iems to try with the 901?

 

[rdsreference]

Yes I couldn't agree more, however Fang seems to think they can drive just about anything apart from the behemoth HE- 600 but I'm on your side I would definitely like a little more slam in the bass dept and even with the balanced card there just isn't enough power to drive full size cans of this size. I don't want to invest more in an amp at this stage but I would love to hear the new centrance m8. My father has a pair of Momentums which I would love to try will report back if you wish

 

[brunk]

   
I think perhaps 901 is best used with iems, full size headphones might be a bit too hard to drive with enough authority. I loved my he400s with the 901, but I felt the balanced amp lacked sufficient oomph to bring complete control over the 400s bass. Maybe get some totl iems to try with the 901?

 
 

Yes I couldn't agree more, however Fang seems to think they can drive just about anything apart from the behemoth HE- 600 but I'm on your side I would definitely like a little more slam in the bass dept and even with the balanced card there just isn't enough power to drive full size cans of this size. I don't want to invest more in an amp at this stage but I would love to hear the new centrance m8. My father has a pair of Momentums which I would love to try will report back if you wish

 
The HD-800 and TH-900 work surprisingly well out of the 901

 

[rdsreference]

Perhaps if your not a bass junkie you won't find an issue and i'm not but I would like a lower bottom end maybe a Tad looser it's not an issue on all tracks but forget most stuff recorded in the 1980,s generally find it hard to find good recordings unless they are studio remastered.

 

[kkcc]

Perhaps if your not a bass junkie you won't find an issue and i'm not but I would like a lower bottom end maybe a Tad looser it's not an issue on all tracks but forget most stuff recorded in the 1980,s generally find it hard to find good recordings unless they are studio remastered.

 
HD600 is really not for a bass junkie imho.  Try HD650 if you need a full size sennheiser.  Momentum should work too.  I doubt any audiophile DAP/DAC will make enough bass for you on HD600.....

 

[CosmicHolyGhost]

Just checking in to say that I hear beautiful bass comes out of 901 balance mode with high gain on when pairing with 650... Very satisfied and beautiful sound. Imho, Its better than db2 + intruder (full balance) if we talk about portable setup.

Agree to other suggestions of finding the right can/iem for the music you enjoy and good luck.