Is there any DAC compatible with FreeBSD?

Eeek... that's not so great. Of course, that's not really a surprise with this kind of kit. There appear to have been 2 or 3 different versions of it manufactured. If you search the web there are a number of threads where people talk about hardware mods to this dac, including changing the opamps. I noticed all the current 'Aune' branded products are much more expensive, they have taken the brand upmarket, maybe they don't use fake op-amps nowadays.

The company information on the box is "Wuhan Hairerde Science and Technology Development Co Ltd, Hubei Province".
... but, I can't find much information...

The one I have actually sounds quite nice, so hopefully the opamps in it are genuine! Photo shown with the PSU underneath. Yes, my Audinst HUD-MX1 does sound better than this one. But this one works with freebsd :-)

1777743644332.png
 
Oh, man...
View: https://www.youtube.com/watch?v=JUGHmCTarPk

Well, I don't know if my aune dac unit has fake op-amps. It sounds pretty good. But maybe if they use a jellybean the circuit will work almost as well, who knows. I don't feel like taking it apart and rubbing the back of the chips with acetone to see if the writing comes off. Not right now anyway!

This is getting ridiculous... does anyone even use 741's any more?
View: https://www.youtube.com/watch?v=gueH9v-RipI

Get your stuff from reputable suppliers... not ebay or amazon.
 
This one made me laugh, it looks like the burr-brown 'BB' logo has been drawn with a pencil, literally. In fact I've never seen a burr-brown chip that looks like that...
Screenshot_20260503_154029.jpg


Yeah, he says that one was a fake. 😂

I don't really have time right now, but I guess at some stage I can take mine apart and take some careful photos of the pcb. It seems to be working ok though, I've been listening to it with freebsd on the X220 for the last couple of days, it sounds pretty good. Maybe I just got lucky this time. It sounds very nice with my HD650's.
 
I found a thread about the aune dac here https://www.diyaudio.com/community/threads/aune-mini-usb-dac-headphone-amp.171424/
One of the posts has a circuit diagram for one channel.

And there is a huge long thread on head-fi.org here https://www.head-fi.org/threads/hifidiys-mini-usb-dac-mk2-also-a-headphone-amp.407756/
And yet another long thread here https://rockgrotto.proboards.com/thread/6608

It's a pretty old design... the posts start around 2009! I'm not sure what the upgraded PSU they are talking about is, perhaps aune made a psu for it. But I have mine powered from a nice regulated linear psu that I already had, not a switch-mode.

The PSU I am using is this one, at 15V:-
(or search for "r-core linear power supply", the design is supposedly based on a studer mixing desk psu)

Based on the recommendation from the Gabster in this video, he tested the ripple on a selection of these cheap PSU's.
View: https://www.youtube.com/watch?v=WLJGE5SSW2A
- as he says, just don't get the 'de-luxe' one with the digital voltage display, to avoid the ripple caused by the display electronics; get it in the plain case instead;
- on his point about the chassis not being grounded, I checked inside mine and found that they have added a ground wire internally, so that appears to have been fixed.
 
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It looks like this design started life as a kit. http://bbs.hifidiy.net/thread-200287-1-1.html and https://weekly-geekly.imtqy.com/articles/146966/index.html
Mine is completely silent in the headphones when there is no input signal, even with the volume on 100%, no hiss or hum. There is no crackling when I turn the volume pot. I think what I've got is a cleaned up and productised (ie, factory built) version of the original kit (hopefully, anyway). The 'aune' engraving on the fascia on my one is different from the 'hifidiy' engraving on the kit version.

Oh well, the one I've got here works very nicely with freebsd 14.4 on my thinkpad, that's the main thing. I will be surprised if it's really got fake opamps inside, it sounds too good for that.
 
What I have in hand and worked as DAC (as a DAP is included) on FreeBSD at least the last time I've tested are:
  • CHORD Mojo
  • SOUND GEAR PAV-HADSD
  • FiiO Q3(2021)
  • FiiO M11 (DAP, USB DAC mode)
  • FiiO E7
Note that I'm mostly using CHORD Mojo now, but PAV-HADSD is old but handy as it has LED indicator to show at what frequency it's now locked at.
 
Chord gear was always nice ... :)
 
I'm not sure about the aune mini usb dac v2 SE. It has a very wide and expansive sound stage, much wider than the other dac's I've listened to. On some music it sounds really fantastic, but on other tracks it sounds less great, parts that were previously prominent become indistinct and hard to follow, and overall coherence is lost. It's almost as if a DSP FX was being applied to the music, yet it's hard to see how they are achieving that, unless the dac chip itself has that effect. I have read elsewhere that the (higher quality) Grace M902 and Burson HA-160D used the same PCM1793 dac chip and also have very wide sound stages, so perhaps this is a PCM1793 thing. Interestingly TI has superceded that part with the TAD5242 https://www.ti.com/product/PCM1793 , so the PCM1793 is previous generation tech. They have a couple of interesting application notes on that link too.

I noticed too that there is a pronounced burn-in effect, the sound quality has noticably improved over a few days of listening to it, I don't think the guy who sold it me used it much. And there is the fake op-amps question, too. So, it's a bit of a mixed bag. I'm not sure I'd recommend it to anyone else, other than to satisfy your curiosity. It works with freebsd, but you may or may not like the effect it produces.

Having said that... the one I have here sounds great with my 250 ohm DT 990's, as well as the HD6XX's, with the right music! So whatever the fake op-amps they are using are, they can't be too bad; or perhaps I just got lucky and got a good example. The way it sounds is definitely growing on me.
 
OK, so I got a brand new pair of beyerdynamic DT 990's and have been burning in the Aune dac with 24-hour a day playing the lofi live stream. It's gotten really nice now, I'm pretty sure the one I have doesn't have fake op-amps. I'm going to revise my last post and give a definite recommendation for this dac / headphones combo. I've been playing it continuously with freebsd 14.4 using alternately waterfox or (mostly) mpv directly from the lofi url, and freebsd hasn't missed a beat. Of course I haven't worn the cans 24 hours a day, but whenever I have put them on I've heard zero faults... no pops, clicks, hum, any other junk. It's stayed up for roughly the last 3 days, playing non-stop. I'm using oss with default settings, I haven't set up bitperfect. Well, it sounds pretty good. When I ran the frequency sweep hearing test my cut-off was about 13 kHz, but hopefully I'm not missing anything much. I thought you might like to see a photo, hope you will excuse my messy desk, I keep meaning to clear some of the junk up but you know how it is... :)

aune-dt990s.jpeg
 
I found a couple of good webpages here that talk about the different dac technologies that are available and gives some examples of dacs of each type. I am interested in 'musicality' above all. I want to try an R2R next, and perhaps later on an AKM based dac. The Aune dac I have is a Burr-Brown design, and I agree with what they say about a "rich and detailed sound". Interesting that the iFi Zen is a burr-brown based modern dac. The Chord Mojo is interesting too, using their own designed "dac chip" implemented on a Xilinx FPGA. The high-end boxes like Denafrips, Hololabs and Laiv are way beyond my budget...

I probably need to be careful getting devices with an xmos usb interface, given the comments about problems with xmos and freebsd here https://m4c.pl/blog/freebsd-audio-setup-bitperfect-equalizer-realtime/ .

I was wondering if one of these Fiio K11 R2R's https://www.fiio.com/k11r2r will work with FreeBSD. Head-fi.org liked it: https://www.head-fi.org/showcase/fiio-k11-r2r.27363/ , obviously it has some technical limitations at the low price (for an R2R) but they liked the sound. Has anyone tried one of those with FreeBSD? Maybe I'll just get one to try... 😁
 
I'm an "audio man". Many dacs here.
Scarlett 8i6 fails big time. [Routing problems,only windows drivers...]
Scarlett 2 , ok , but no good quality. Hmmm, buzz.
Must retry my Beringer U-Phoria UMC404HD.
Not bad ...
 
Fiio K11 R2R. Works fine with 14.4-RELEASE and oss. It sounds better (more dynamic bass in particular) when used with a decent quality external headphone amp, but the built-in amp is ok (set gain preset to 'H" for high-impedance headphones). I left UAC set to 2, which appears to be the default. It worked as soon as I plugged it into the laptop, I didn't need to do any setup in freebsd. I used a 12V linear regulated PSU I already had, rather than the switchmode mains adapter it came with, although after studying the block diagram there may be no benefit as it derives all circuit voltages from an internal converter anyway. It worked fine with my linear PSU, of course. Sounds very nice with both the HD6XX and DT990's; lots of detail and wide sound-stage, no artefacts that I could hear. Detail and resolution were excellent. This is a good one.

I tried both NOS and OS modes (oversampling off and on), I thought it sounded a bit better in OS mode. Thankfully there is a menu item to switch off the coloured lights on the top of the case. The control panel LCD has a lower brightness setting too (3 brightness levels). The one I tested came with firmware version M79, which the website says is the latest.


fiio-k11-r2r.jpeg


There is one thing I didn't like - the high price. For a bit of mass-produced consumer electronics in a cheap plastic case, the retail price of these is very steep. I took the base off to have a look at the PCB... its the typical mass production high-density SMD construction, like you would find in umpteen other cheap appliances; you're not going to be repairing this yourself. The pcb looks very similar to the type of board you find in a mini-pc, but with a lot fewer components. I think there is a large hype element in the current retail prices of this kind of kit, they are 150 GBP here which I think is very steep.
 
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I decided to move from Windows 7 to a BSD or Linux OS on desktop and I'll start a home server probably with FreeBSD. I have a few concerns because I have a few USB devices which has drivers / applications only for Windows. One of them is a Suunto Ambit3 sport watch, the other is a Sabaj D3 DAC. I asked both companies if they could support Linux or BSD, but they did not like the idea. It was a hard decision, but I decided to give my DAC to my brother and buy a new one. I'd like to know if there is any DAC (around $100) that works on the other side of the OS realm. I know this is a little bit grey zone, because the question is not just about FreeBSD, sorry for that.
SMSL SU-1
 
That's about the cheapest one around with an AKM dac chip, that was discussed here https://www.hifiverse.io/articles/audio/best-dac-under-in-2026
"SU-1 uses the latest AKM DAC chip, AK4493S to achieve a distortion of less than 0.00013% " Of course that's the lowest cost AKM on the market.
That's another one I'd also like to try... not sure I'm going to be allowed to buy another one very soon though! Note that it's purely a DAC, there's no headphone amp in the SU-1.

"The whole DAC is based around the Asahi Kasei’s AK4493s DAC chip. Powerful XMOS XU-316 will accept the USB signal and provide high resolution for both PCM (up to 768 kHz, 32 bit) and DSD (up to DSD512)."

However, since this has an XMOS usb interface chip, does it definitely work with freebsd, given the warning about xmos with freebsd stated here: https://m4c.pl/blog/freebsd-audio-setup-bitperfect-equalizer-realtime/

Quote: "It must be said, however, that there is one very important difference between FreeBSD and Linux. While in Linux, even in bit-perfect mode (hw:0,0) virtually every built-in sound card or USB DAC works correctly, the same cannot be said for FreeBSD. It happens that the enabled parameter dev.pcm.%d.bitperfect=1 implies problems. For example, one of these is the failure to properly recognise the PCM format descriptors supported by the device (especially true for XMOS communication chips)." Although it sounds like the problem may only apply to bitperfect mode?

Does the SU-1 definitely work with freebsd?
 
I found an interesting discussion about R2R dacs here https://www.diyaudio.com/community/threads/are-r2r-dacs-inherently-better.420514/

The closest thing I found to a teardown of the Fiio K11 R2R is here: https://www.techpowerup.com/review/fiio-k11-r2r-desktop-dac-headphone-amplifier/3.html
It mostly looks pretty clean, but not everything is wonderful, check out the crap hand-soldering in this photo. These things are built down to a price. Luckily that knob is just a digital switch, not a pot in the audio signal path. The one I've got does sound good. But it's a pretty cheap build.
1778330830029.png
 
Nuforce udac5. I wanted a small high quality dac and headphone amp for portable use. This one has an ESS SABRE dac chip.
Review here https://en.techreviewer.de/nuforce-udac5-test/ and here https://the-ear.net/review-hardware/nuforce-µdac5-digital-analogue-converter/

It works well with freebsd. Amazingly it has enough output power to sound reasonable with my 250 ohm DT 990's. Definitely an upgrade on the thinkpad's onboard conexant chip. Power is derived from the USB cable, there is no separate power supply. It worked straight off with oss on default settings, I didn't have to change any sysctls. I didn't try bitperfect...

This one is definitely a step up on the various aliexpress dongles I've tried. It's nice having an analog volume control as well. Build quality looks excellent; I couldn't hear any noise from the volume pot. With volume set to full and no music being played, I can hear nothing in the headphones, no hiss, hum, etc. No pops, crackles etc when playing music. Nice.

udac5.jpeg


It appears NuForce has morphed into NuPrime https://nuprimeaudio.com/product-category/dac-hpamp/ . They still make dacs, but sadly don't appear to be making the udac line any longer, at least, I couldn't see any in that list. But they do have a CS43131-based inline portable dac https://nuprimeaudio.com/product/hi-mdac/ . Ebay is your friend, as usual. The main thing is it works fine with freebsd. If you want a tiny dac plus headphone amp to go with a laptop, this is a nice one.

We're doing pretty well so far... every dac I have tried has worked with freebsd, except for the Audinst HUD-MX1, which is a shame as the Wolfson dacs have a sound I particularly like. I haven't tried an AKM yet either, they all seem to have XMOS usb interface chips, I still don't know if that is a problem or not.
 
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