Is it possible to use custom EXFAT driver with 2.2.0? Actually 2.2.0 sounds best to me (and, reading this thread, to some other people). Thanks Mr. Lurker for all of your amazing work!

@Paul: Oh, thanks, it's been my pleasure to measure such fantastic DAP (and confirm the high-end level of performance!) Dear Paul, one thing I discovered is that with the latest (2.2.0) firmware, when used as USB DAC, DX90 ignores the digital filter setting, always using sharp rolloff at any...

Yeah, folks... Let's better take a look at my next DX90 measurements, now at 96KHz/24bit:   So the digital filter setting works at 96KHz, too. DX90 frequency response (with sharp rolloff) is flat up to almost 50 KHz!     The second graph is the noise floor measurement. IMP-RESS-SIVE...

Below you can see my older post. So for 16/44 material, DX90 oversampling DAC uses either Sharp or Slow rolloff digital filter. These filters both affect sound. If iZotope upsampler is capable of better math than used in both DX90 options, this is already the reason for better sound. Also, If ...

I suggested the settings that make 44/16 signal sound better when played through our beloved DX90 specifically. I do not force anybody to try, but a smart person can try and would never go back to stock.  

95% of expensive modern DACs (I mean not chips, but DAC devices) come with one or another upsampling implementation. OK, upsampling isn't everything. But it isn't useless. Just try and hear the real, sometimes huge difference in blind test. But of course not with $30 headphones. Better heard...

@ALL: As DX90 has no upsampling features, I've been experimenting with 'offline' upsampling (I mean, using different audio editing software, convert 44/16 to various formats such as 88/24, 96/24, 176/24, 192/24). After many, many tryouts, I've got the superb results with different headphones...

@Paul: Thank you! May I report one cosmetic bug I observe since 2.1.8 (persists in 2.2.0). Cosmetic, but scary for an audiophile. I never use EQ, but when visiting its menu, I can see random numbers, and sometimes even one of the sliders shifted. All greyed out, as EQ is disabled, and really...

A person from whom I borrowed the equipment asked me to refer to it as 'good analog-to-digital converter'. This isn't a PC board ;) Other testing details and conditions: my iBasso DX90 with 4200mAh battery and 2.2.0L0 firmware. For this test, 44/24 signal via headphone out, high gain, volume...

Hey all... Just wanted to start sharing some of the DX90 measurements I made today with the prosumer digital recorder. First of all, Slow Rolloff vs. Sharp Rolloff, 16/44 signal:   The cost of the slow rolloff filter can be clearly seen. Less ringing in time domain (not shown in this graph)...

@Zvermetel: Just wanted to respond to a week-old question. I found 2.1.5L2/L3 sounding better than 2.1.8L0 (so I went back to Lurker's 2.1.5L2).   @ALL: Sorry if asked before, but is there a way or a mod to not charge the battery when DX90 is used as USB DAC? Following the good audiophile...

@ZverMetel: Could you tell what exactly got worse with 2.1.8? I'm hesitating to upgrade from oh-so-good 2.1.5L3. I mostly listen at high gain to 250 Ohm Beyerdinamic DT990 and sometimes 43Ohm Shure SRH940.

Currently I'm on 2.1.5 L3. I use high gain for Beyer DT990. Bass is punchy. Not muddy, not too much of bass. I like it. The results are surprisingly good. Maybe my double battery has something to do with it. Maybe not :) BTW usually at high gain I use volume 230-250 according to source music.

DX90 sound is very good, on par with some 1K DACs, would you believe it or not. For best results I use the slow roll-off filter, and of course have disabled the EQ. Upgraded to 4200MAh battery. The result is much pleasing, even for 250 Ohm headphones, such as my Beyerdynamic DT990.

DX90 does indeed sound great, and yes even better with Lurker's 2.1 firmware (so far I test with Beyerdynamic DT990 and Shure SRH940). Just do not use the EQ, choose slow rolloff filter to kill preringing, use high output gain. Avoid MP3, use proper wav/flac/ape files only. With such setup (and...

Hey All. Just wanted to share my impressions after the first few weeks of usage. Simply said, DX90 is the fan-tas-tic device for this price and dimensions. With slow rolloff filter there is no audible preringing - impressively clean sound for such a small player. Even 44/16 tracks sound really...

0.97ns according to http://www.head-fi.org/forum/thread/446375/usb-24-192khz-m2tech-hiface/45 "Cleaner" USB power might have provided better results, though.   P.S. I have some doubts that Fi-Reclock is their (Firestone's) own technology. Anyways, the good news are, being their own or...

Just to clarify: TE7022L can output both I2S and SPDIF. In Bravo, Tenor is outputting SPDIF because Fi-Reclock thing is "made for SPDIF". And, absolutely yes, signal gets through DIR9001. Just by the way, quite a hi-end Furutech Le mans (e.g. see...

This is how Bravo works: