[adydula]

Wow...that day for some has already come and gone. for some its still here....
 
Many people do not like a totally neutral , transparent chain....they are constantly looking for a set of 'stuff' that makes them happy.
 
I would rather have a transparent set of electronics and once I have a set of headphones that have a good freq response....then look for material that is well recorded and mastered....
 
But many people think that there is a magic solution out there that will make all their music sound great, or keep trying to find that amp, that NOS tube, that dac that will make them happy...this headphone with that map and that dac with that cable ......audio nirvana at least for awhile.
 
When I use neutral electronics with a great set of headphones, I have found many really very well recorded and mastered songs. The sound I hear is described as musical, which IMO is the sound is very much like that of a real instrument.....tonality etc....
 
The O2 amp and the T90s are in this category to me.....no glowing tubes, no fancy knobs, doenst weigh 100 pounds, no billet aluminum...it just works very very well and allows us to have a very musical sounding experience with good material. (without breaking the bank or taking out a loan).
 
ok back to reality!!
 
All the best
Alex

 

[genclaymore]

The main reason why I didn't get a O2 Dac is because it uses that Tennor 7022 chip which gave me major issues with asio and other issues which I could never fix when I had the Audio-GD NFB12.0 other then using optical input. Which why I ended up with the 15.32 that I used to have which used the USB32.
 
The other reasons is that I didn't want a portable setup and the O2dac didn't have input connections that I needed like optical and coaxial. it also didn't support the bit rate that I wanted and since it uses Tennor 7022 I knew Asio would been a hassle on it like it was with the NFB12.0.  Which why I wont touch any thing with the tennor chip not even with a 10 foot pole no matter what it is not even if it has other input's as I might need to use the usb input one day.
 
I went with the Bifrost uber because it had the exactly type of sound that I wanted and I knew after a lot of reading and asking that I knew I found the dac for me, It pairs very nice with my Little Dot MK 2 2.0 and my Beyerdynamic T90 to the point that it was the best thing I ever bought which makes me very happy. But of course my wallet is in the corner crying but it was worth it.  Tube rolling gives me a way to customize just my tube amp and nothing else with the headphones I using. Tho I plan on putting either 6H30P or 6n6P in my Little dot MK2 2.0 to replace the stock power tube's but I haven't decided on the driver tube yet, Tho I am looking at the 6Z1HP-EV which should pair nicely with my T90, tho I wanted  M8161's but those non-existed on ebay in the usa, as I don't trust getting tubes outside of the usa in case something was to happen as I don't fancy shipping tubes back to Russia.

 

[jbarrentine]

Can anyone recommend better pads? In my experience the Beyer pads are just too damn soft and prone to pad crush in an absurdly short time. My 598 never did this. 
 
Are there gel pads that will fit the T90?

 

[MrEleventy]

What's an absurdly short time? Curious because I've had mine for almost a year now averaging 30+ hours a week and they're still plush and solid.

 

[jbarrentine]

What's an absurdly short time? Curious because I've had mine for almost a year now averaging 30+ hours a week and they're still plush and solid.

 
7 or 8 months now. I have a big head.

 

[MrEleventy]

7 or 8 months now. I have a big head.

Ahhhh, that'll do it. Maybe stretch them so they won't clamp as hard? Or you can try restuffing them with memory foam. I did it to a pair of HD600s when they were flat and it worked out great. Link to foam replacement

E: Video link!

[VIDEO]https://www.youtube.com/watch?v=_b53VDWA10k[/VIDEO]

 

[Paspasero]

Just received a pair of these and I am getting a very noticeable hiss on both drivers. It creates a muffled scratching sound. Anyone know what it could be? Are the headphones a dud or is it my music files? I was just streaming stuff quickly on Spotify using the high quality premium service. 
 
Edit:  Also just for background I am using a Fiio E9 and an JDSLabs ODAC.

 

[plakat]

It is identical on both channels? Would be rather surprising to get a headphone with not one but two identically damaged drivers, so that would lead to questioning the source material...
Did you try other (local) files? Is the connector sitting correctly? Do you use an adapter (3.5mm -> 6,3mm)? If so does that adapter work correctly? Is the plug sitting correctly? Did you try pulling it out just a tiny bit?

 

[Paspasero]

  It is identical on both channels? Would be rather surprising to get a headphone with not one but two identically damaged drivers, so that would lead to questioning the source material...
Did you try other (local) files? Is the connector sitting correctly? Do you use an adapter (3.5mm -> 6,3mm)? If so does that adapter work correctly? Is the plug sitting correctly? Did you try pulling it out just a tiny bit?

It seems like it yes, but say for instance the song Mr. Brightside by the killers, the song starts off on the left channel and I can hear it on that side only. But when the right channel comes in I can hear it there as well. I unplugged everything and reseated all the cables. Also the connector is sitting properly as far as I can tell. I don't get the same buzz on my HD598s. 

 

[MrEleventy]

Hmmm. Do you have anything else you can try running it off of for testing?

E: How about this, plug it into the E9, start playing something then pause and turn up the volume? I think it's either E9 or the tracks.

Bah... My FLAC copy of Hot Fuss is corrupt. Time to rerip.

 

[plakat]

If the problem is easy to hear it might indeed be helpful to try any other source... as I said above, two drivers damaged in an identical fashion seems rather unlikely to me (though possible of course).
 
As I see the HD598 has 50Ohm, while the T90 has 250OHM impedance... maybe the E9 (or your specific unit) has problems with that? Did you ever use any other headphone with higher impedance with it?
 
If all fails you can only send it back I guess... it might be a simple defect like a bad soldering point on the shared ground (which would explain the hiss on both drivers), but that might not be easily repairable on yourself (and voids the warranty).

 

[Paspasero]

Hmmm. Do you have anything else you can try running it off of for testing?

E: How about this, plug it into the E9, start playing something then pause and turn up the volume? I think it's either E9 or the tracks.

Bah... My FLAC copy of Hot Fuss is corrupt. Time to rerip.

Not really. Just my phone or tablet. I tried running it straight from the DAC and the hissing is a bit more muffled but it is because the ODAC really accentuated the bass in every track I played. I know there is inherent background noise on tracks. Could it just be that I'm hearing the inherent flaws in the track? I mean I can tell that these are some really technical cans and definitely blow my HD598s out of the water. 

 

[Paspasero]

  If the problem is easy to hear it might indeed be helpful to try any other source... as I said above, two drivers damaged in an identical fashion seems rather unlikely to me (though possible of course).
 
As I see the HD598 has 50Ohm, while the T90 has 250OHM impedance... maybe the E9 (or your specific unit) has problems with that? Did you ever use any other headphone with higher impedance with it?
 
If all fails you can only send it back I guess... it might be a simple defect like a bad soldering point on the shared ground (which would explain the hiss on both drivers), but that might not be easily repairable on yourself (and voids the warranty).

I wish I had another good source handy. All I have is my S5 and Note 10.1 tablet. My E9 is slightly old probably 2.5 years already and I got it second hand. But I used DT770's 80 Ohm versions and those were fine. Oh.. the E9 has a high gain switch on it. I totally forgot. I will try that later... That could definitely be it...

 

[plakat]

High gain might help driving it but introduces a higher noise floor...
 
Nevertheless if might of course be simple: the T90 might be better at showing details in the treble region that the HD598 might simple swallow... so maybe the hiss was present all the time...
 
Maybe there's someone in our area that will help you out with an amp? If you were located near Vienna I'd be glad to help.

 

[MrEleventy]

Even tho it's a 250 ohm can, the T90s is efficient enough to run out of a source directly, like the S5. Not ideal, but you can at least play tracks off of it and see if you hear a similar hiss.