Audiophile question

@johan-bjareholt your explanation is technically (mostly) correct, but misses what reC claimed.

I’d just add that USB cables nowadays work in the similar speed levels as network cables. Usually they don’t need shielding because they are much shorter, and possibly also use the twisted pair “trick”.
What’s more, the data line is kinda self-neutralizing, meaning within a very short time (every few cycles) the same amount of 1’s and 0’s are transmitted, esentially resembling a constant 0.5.

@reC is not saying the noise is bad to the digital data, but the digital data is bad for the DC, making it unstable. What you have to realize though, is that a USB 2 device has a clock-speed of 480MHz, while your DAC has 48kHz. So, during the time the DAC converts ONE sample, the data line transported 10,000 bits, guaranteed to be 0.5 on average, and never more than 5 consecutive 0s or 1s. The impact on the DAC will be homeopathic. You can not stress enough how much higher the influence of the power source is: The DC that you receive from the PC (USB port) is already a mess, or at least you really have to expect it. The CPU might adapt it’s core voltage several thousand times a second. THIS has an impact on what DC external devices see. And for this reason, a good DAC has to be able to cope with unstabilized DC (which is possible), but a shielded or gold-plated cable will not help the slightest.

The definition of snake-oil is “no useful, scientifically proven effect at all”, not “I don’t need that extra quality, I’m already satisfied with the standard”.


to be honest i have no idea what you just said about those numbers but i believe in the power of experiments so i’m going to order myself - the first chance i get - the most expensive pair of usb audio cables and if i can’t perceive a good amount of difference between the standard “stock” usb cable and the expensive ones i will return the products as faulty and get a refund just for PAVLOVs dog sake.

i’ll be sure to try not to make a fool out of myself tough :stuck_out_tongue:

I have the Radsone DAc for pre-amp and headphone amp and it rocks $75. My phone, a SONY, the company that pioneers hifi, only allows 16 bit output. I am NOT an expert but it does not allow me to play the highest quality sound from my FLAC and WAV files. And I think my BOSE bluetooth wireless won’t allow this either. I have the high end monitors for the 2.5 jack but I don’t have balanced output yet. I think.

OK short story long I am OK with a wireless pre-amp and using the Librem phone would be convenient for an audio player. But it sounds like I will be forced to get a Cowon player type device to get the 24 bit sound.

Be nice. I only dabble in audio. : )

maybe so. but that doesn’t mean that if you would play them in 24 bit output you would be able to tell a difference. just read about audio cds and why they have been standardized in the way that we’ve come to know them for so many decades …

a true balanced audio autput with full end-to-end support (DAC/AMP, wires, iems) would be more beneficial in terms of how you would percieve sound quality.

or maybe you’re just one in 1 bilion that has an extremley sensitive hearing and can go beyond the analog 22khz range.


I’ve been really happy with my Cowon- can’t remember the last time I ran the battery down all the way, and having custom EQ’s for different headphones is really nice (and they even have a couple models running embedded Linux software). It would be great to have the ability to integrate a quality DAC/Amp into the Librem but the “audiophile Linux smart phone user” is a pretty small group- might be hard to sell the phone if they catered to us, and I’d rather see them sell enough to make Google/Apple nervous :slight_smile:

Audio DAC: Wolfson Media WM8962, see FAQ.


Not bad! Looks like it will handle 24bit/96kHz files…

those numbers don’t really mean much if the internal interference is strong. a good dac can be 16bit/44khz max(CD bit-perfect quality) and if it is properly isolated and internal interferance limited then it could - potentially - produce higher quality sound. it probably will not have any dedicated hardware for filtration and balancing so that will be the job of an external DAC/AMP.


a quick update. i’ve done a quick test with my new ifi products (cable+purifier+amp/dac) but my iems seem to be a bottleneck in my test (i assume not sensitive enough). with my current setup it (the cable SEEMS to make a difference-ish but … for those of you who are reluctant (for a good reason probably - the cable is too expensive for the marginal difference it offers-ish) you could try the i-purifier from ifi the usb A-female variant - the one i have - comes with both micro-usb to usb A-male and usb C to usb A-male adapters so it will work for the Librem 5 also. i’ll update again (in a few years) when i upgrade my iems.

test source - “the chain” by Fleetwood Mac < FLAC from original CD (44khz @ ~1mbs)

I agree the DAC of the phone is an important consideration. The other one is if this will be able to amplify well enough to drive some decent headphones. In the end if I need external solutions for this I am not that discouraged by it.

I’d love to see an integrated Schiit DAC, as they’re all already Linux native, but the worst case you could pick up one of their amp/DAC combos and use it.

from what i’ve seen most external AMP/DACs have better support under the Linux kernel than they do under macOS or windows10. not sure how the libre-linux kernel handles the closed-firmware but the more blob-tolerant linux handles it like a champ. so excited to test with the L5 once it’s in my hands.

You know, that would be fantastic! Listening to a Vali/Modi as I type…

just bumping and linking to the final specs

Curious to know what make the final specs different from the selected Wolfson DAC.

Personally I have never expected a phone to be a good replacement for my portable rig. I do appreciate Purism decision to include a decent DAC though. In an ideal world there would be a phone dedicated to audiophiles.

LG does a good job with V series. Especially w V10 and V20. But, yeah definitely not powerful enough.

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What will you be using for audio playback on PureOS? Foobar2000 (Snapcraft)?

any (well FOSS ofc) audio player that has a decent GUI and supports FLAC or other uncompressed formats. i like listening to sound in lossless quality if possible. the L5 supports up to 2 TB microSD cards so that’s not a problem.


probaby just that lollypop . I like that it has an oboard 10 band equalizer . I just hope it has a hierarchical folder view for my 100gig music collection .


Lollypop looks nice, a GUI oriented player capable of playing .FLAC.

Any playback through kernel streaming, supporting .FLAC and .WAV? Most of my album files are 24/96 and up. Would be nice to have Foobar2000 and its mobile web server version on PureOS or any other recommended players capable of doing that