Single board computer as audio player?

[semioticwafture]

With the huge success of single board computers over the past 5 years, I'm surprised I haven't yet seen a niche audio player using that technology. Recently it appears battery powered SBCs have got more practical.

Has anybody tried this?

The "Chip" SBC seems suitable. It supports battery power and what looks like suitable small screens. They don't sell batteries in their online shop at the moment though, and I don't think the small case there has space for a battery or screen either. Some of that may be a temporary thing, this sort of thing seems often to have variable availability because of batch manufacture.

The nice thing about SBCs is that they're really just tiny desktop machines (albeit ARM based), which means you don't need special embedded software development know-how to write software for them.

I'm tired of commercial audio players: seems the software gets worse with time since smartphones arrived...

[cromag]

Even with current prices I think single board computers are better positioned as full-fledged audio and video media centers rather than just audio players. A friend of mine is using a Raspberry Pi for just that purpose.

As far as audiobooks are concerned, I think they'd be pretty bulky to be practical. Even with batteries it sounds like they'd be more "luggable" than "portable." I suspect they'd also suffer from the same problem that inexpensive Android tablets have -- relatively unremarkable audio output.

On the other hand, if you're looking for a high-end audio player for high quality music listening, there are still a few options. I have -- and can recommend -- the FiiO X1. I don't think that its software would be especially good for audiobooks, but it does a great job with music. I've got the first gen hardware -- the second gen hardware specs look even better -- all for about $100 at Amazon, etc.

[semioticwafture]

Hey cromag. The great thing about DIY and general purpose computation is that there is no "positioning" as far as as we the customer is concerned! You can use them for whatever you damn well please :-) In the commercial MP3 market, I suspect there is nothing in production that even has the very basic features I want, let alone any decent software polish or tweakability for itch-scratching.

The CHIP costs $9 sans battery, case, screen.

Re bulky: what would be your guess about which direction that is heading? Yeah, mine too :-) Somebody will be selling watch form factor PCs soon (though it remains to be seen what wired IO they will have, so far it seems it's not going away on the smaller boards). As of right now, take a look at the CHIP:

http://makezine.com/2015/11/28/chip-vs-pi-zero/

This kit could be rearranged with a 3d printed case to make something smaller. The screen is larger than needed, I think could be replaced with smaller device (haven't looked into that). The battery is not huge but probably is thicker than needed, again haven't looked into replacements.

https://getchip.com/pages/pocketchip

FiiO X1: looks like no MTP? That illustrates a problem: there really aren't "ends" of this market for me, only a small set of features I'm feeling the lack of, which it seems the market happens not to cater for. Also, with this kind of thing when it breaks (has been frequent for me), you have nothing and typically it's discontinued so you get to repeatedly spend time looking for a replacement which may be worse in various ways, which is an annoyance. Stark contrast with PC software - most of the software I use are the same programs as 20 years ago, but they have evolved to be far better in many ways than they were then.

The nice thing with general purpose hardware is that there is some continuity, so the software can actually get better with time (!), parts can be replaced when they break, and if a board goes out of production, you swap it out with a different manufacturer. Of course it may get hard to find ones that have audio (because bluetooth), but that should be fixable with a small addon module (e.g. USB) - and actually so far it looks like all that will be needed to add is the 3.5 mm connector itself, not the electronics. In principle physical board sizes could be a problem for swappability, but that may be dealt with either with a slightly over-sized case or maybe just the contined shrinking size of computer hardware.

Battery life right now with the PocketCHIP is tolerable I think though could be improved (it's designed for gaming and claims 5 hours, so taking both over-selling and the fact that screen can be dimmed for audio playback, 5 hours seems conservative target).

In fact having thought about it a little writing this, if there was PocketCHIP in stock (sold out, more due later Q1 apparently) I'd order one right now, start with some existing player like GMU (see below) and then maybe upgrade it stepwise as and when I get time and feel like it. Get MTP running. Find a smaller screen + cardboard and duct tape for my first case. Thinner battery. 3D print a case. Add a Python UI, or swap out MTP for something else, or patch it to fix irritations for podcasts / audiobooks / classical music, like per-track last-played point. I'll keep an eye out and who knows I may report back...

https://bbs.nextthing.co/t/media-player-gmu-port/6295/7

[semioticwafture]

Re-reading your post: you make a good point about audio quality. I have to admit I'm personally uninterested in (what I see as) emperor's new clothes audiophile snobbery, but interference from digital switching can be a real problem by causing high frequency audio noise.

I guess I'll try it sometime and see if it's a problem for me in practice. If it is, maybe I can find a small USB DAC, with a bit of aluminium foil shielding. Maybe dismantling one of the commodity PC USB external audio adaptors might yield what's needed, but I haven't tried that...