[Sorensiim]

Unfortunately you didn't miss the final signed version of the USB DAC driver.

Dammit, I hate waiting...
 

 

[lhamp]

So... for some reason my dx90 appears to be toast. Went away for a couple weeks and hadn't used it. When I went to try it this morning I hear a steady, high pitch sound coming from the headphones. Nothing else. Just a steady sort of whine. I replaced the battery. Nothing. I installed the firmware again (International 2.1), rebooted, factory reset, erased the img... nothing... just that sound.
 
Any ideas? Time to contact ibasso? (which i would but their site is down. Again.)
 
Thanks.

 

[Lurker0]

So... for some reason my dx90 appears to be toast. Went away for a couple weeks and hadn't used it. When I went to try it this morning I hear a steady, high pitch sound coming from the headphones.

Just in case: do you plug the phones into the phone output? It sounds like you use digital output.

 

[Krautmaster]

they webpage reminds me on a 5 guy garage company, any how...

 

[Krautmaster]

Just in case: do you plug the phones into the phone output? It sounds like you use digital output.

that would be epic

 

[lhamp]

OMG!.... I've lost what little credibility I ever had! I feel like such an idiot. Yes folks... I plugged into the digital out. I must have been away much too long.
 
Thank you Lurker for the highly technical fix. Don't know what I'd do without you guys.

 

[Krautmaster]

no way >.<

 

[lhamp]

I know man... totally epic.
 
What can I say... it's been a tough few weeks. But I even surprised myself with this one. 

 

[Krautmaster]

never missed the right hole neither in my DX90 nor anywhere else - oh, that remembers me on that song,
 
https://www.youtube.com/watch?v=IRV5RLp6L1Q
 
Lyrics -> http://www.lyricsmode.com/lyrics/s/steel_panther/just_like_tiger_woods.html
 
HQ -> https://www.dropbox.com/s/t0hca8cyocl233p/Steel%20Panther%20-%20Balls%20Out%20-%2003%20-%20Just%20Like%20Tiger%20Woods.mp3?dl=0
 
5th block, well, i think i posted the song few posts ago
 

 

[jk47]

HD700, K812 and dx90 gain settings
 
 
[i've posted this in 3 threads, fwiw, on the theory that it might have relevance for each.]
 
music for testing:
 
1. melos quartet schubert's “death and the maiden” 2^nd movement- I like the melos' performance for its prominent cello and for its emotionality culminating in periodic very high, richly textured, notes from the first violin. The cello would display the bass but not the lowest bass.  the violin would demonstrate the treble.
 
2. Charlie hayden & pat methany- “first song [for ruth]” – hayden's playing on the double bass goes down to what I think are the lowest notes the instrument can produce.
 
–----
 
I posted some time ago that my hd700 sounded dull and lifeless when driven by my dx90, but only later realized that i'd only tried it on low gain. So last night I tried it on high gain, and compared it to its performance when driven by my integrated amp [nad c 375 bee].
 
Indeed it performed much better on the high gain setting. Across the spectrum, it preserved the sounds produced by the hd700 when driven by my amp. The soundstage, however, was somewhat smaller. With my amp, the hd700 produces a 225o soundstage [approx of course], while from the dx90 on high gain it was more like 135o.
 
–-----
 
I've been listening to my k812 on low gain from the dx90, and took this opportunity to try it from the amp. In general, the k812 has more bass and treble extension than the hd700, and sounds a lot airier, with more separation of instruments. In comparison, the hd700 sounds slightly congested, and the lowest notes lack texture and sound dull compared with the k812. The k812 sounds better; it should, as it costs twice as much. [I decided last night that I should sell my hd700. Pm me if you're interested, u.s. only.]
 
From the dx90 on low gain, the k812 produces a very airy sound, with excellent separation of the instruments, with good extension and texture across the spectrum. It produces about a 135o soundstage. I tried the k812 from my amp, not clear about how the impedance mismatch would affect its performance. The k812 then produced the same sound, but with a 225o soundstage.
 
Some time ago i'd tried the k812 on the dx90's high gain, and thought the sound was actually degraded on that setting. I decided last night to try the medium gain setting, which i'd [falsely] assumed would also degrade the sound, but to a lesser extent. Instead the medium gain setting produced a 225o soundstage while maintaining the quality of the sound. This is how i'll listen to the dx90 in the future.

 

[goodvibes]

Med. is what I like as well. 

 

[Lurker0]

Thank you Lurker for the highly technical fix. Don't know what I'd do without you guys.

I used to work as a tech support and know that **** happens even with experienced users

Edit: The quote from Forrest Gump was censored! What a shame!

 

[headwhacker]

Same here, med gain is the best SQ for me. Both in Rockbox and Mango. Based on the measurements I've seen so far DX90's amp tops out at around 2.1 Vrms before it exceeds 1% THD. So it makes sense the Med gain is the sweet spot.

 

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

Low gain has the best SQ imo if absolute neutrality is what your looking for, but it does sound a bit flat and boring (but reference), from my listening low gain also has the best micro detail retrieval of all gain settings. Mid gain is a good compromise between the neutrality of Low gain and the fun factor of High gain. I definitely find high gain to have the lowest SQ, there is a considerable veil on micro detail and certain frequencies are boosted making a shouty, boomy, V shaped sound .
 
I also have a theory about this 

 I believe a big part of this has to do with the BUF634 op amp used in dx90, which in my experience with op amp rolling in the iBasso P4 has this effect of accentuating a V shape sound and with a loss of resolution and veiling the higher the gain is. Basically the BUF634 is degrading the sound with increasing magnitude the higher the gain, even on the lowest gain the BUF634 is limiting absolute transparency of the DX90. So I'm not a fan of it.
 
The main reason the BUF634 is used in DX90 is keeping the power supply stable when large amounts of current are being drawn (its a unity gain buffer), which is only needed when powering bigger or harder to drive headphones. So basically the BUF634 is a compromise to make the DX90 better at driving bigger cans but limiting the transparency of the power supply in the process which can greatly affect iems or any transparent headphone. I would personally prefer the DX90 without the BUF634, for example the iBasso P4 amp sounds considerably cleaner and transparent without it and I'd bet my savings the DX90 would too.
 
If I had excellent soldering skills I would probably try take the BUF634's out and replace them with transistor buffers, if they fit.

 

[Jensenchua]

  I know man... totally epic.
 
What can I say... it's been a tough few weeks. But I even surprised myself with this one. 

LOL, this proof we all sometimes do makes some real stupid mistake including myself