Categories
audblog computers suck

Raspberry Pi as a USB audio capture device

The Raspberry Pi’s hardware and software support has come a long way in the few months it has been in the wild. I first tried this application in the summer, and the results were dismal. Now, thanks much improved USB driver support under Raspbian, I’m pleased to say it works flawlessly.

Earlier this year, I bought a turntable (ack!) for transferring vinyl to mp3. I have a TC-772 USB phono preamp, which spits out a 48 kHz stereo audio stream. If you plug the USB output of the preamp into a Rapberry Pi (running Raspbian Wheezy with all the updates), it’s instantly recognized as an audio device:

$ lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 002: ID 0424:9512 Standard Microsystems Corp. 
Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp. 
Bus 001 Device 004: ID 08bb:2902 Texas Instruments Japan PCM2902 Audio Codec

If you install the ALSA recording utilities (sudo apt-get install alsa-utils pulseaudio – this should pull in a whole bunch of necessary packages), you can record directly from this device with the following command:

arecord -D 'pulse' -V stereo -c 2 -f dat -d 900 out.wav

which records from the ‘pulse’ audio device, displaying a stereo text VU meter (handy for setting levels), writing to a two channel 16-bit 48 kHz file called ‘out.wav’ for a maximum of 900 seconds (15 minutes). arecord has a baffling number of recording source options; arecord -L will show them. ‘pulse’ was the first one I tried.

So how does it sound? Here’s a 30 second excerpt from the only single I owned for years, The Music Tapes‘ “The Television Tells Us/Freeing Song by Reindeer”: Freeing Song by Reindeer – excerpt [mp3]. I’ve saved an even smaller snippet as lossless FLAC so you can see that the waveform’s pretty clean: FreeingSongbyReindeer-tiny_excerpt [flac].

Sounds pretty good. Not quite as good as having Julian play it in your house, I’ll allow, but not bad for a first try with a $35 computer.

Categories
goatee-stroking musing, or something

Well, that about wraps it up for vinyl audio quality, then …

— from the United Record Pressing FAQ.

Categories
audblog

“Go scratch a rock on some congealed oil and tell me what it sounds like”

I’m either getting old or conventional, ‘cos I bought something I said I would never have enough time or space for: a turntable. I won’t forsake my beloved MP3s, but there are somethings you just can’t get electronically. One of them being the 1981 Stampfel & Weber album “Going Nowhere Fast”, which I snagged from Etsy from a west coast seller.

I bought an elderly Technics from Ring Audio, and set it up with a USB phono preamp from Phonopreamps.com. It sounds good, I guess. It certainly sounds different from MP3s, but better …? Dunno. My two cynical theories hypotheses of vinyl snobbery are:

  1. The more you have invested in your system, the more confirmation bias tells you it sounds better.
  2. Vinyl is the record industry’s last-gasp attempt attempt at relevancy, because you can’t home-cut your own discs. As there’s always analogue loss in ripping from vinyl, it’s self-policed rights management by the sound quality snobs. Imagine that: DRM conditioned into the listeners themselves!

I have not got a lot of records:

Albums

  1. Going Nowhere Fast — Stampfel & Weber
  2. The Holy Modal Rounders
  3. The Holy Modal Rounders 2 (are you sensing a pattern here?)
  4. Acedia — Black Walls

Single-ish Things

  1. The Television Tells Us / Freeing Song by Reindeer — The Music Tapes (Julian sent me this in 1998, and I think this is the first time I’ve played it. For a few days, it was the only record I had, and it was merciful that Catherine was away, as she only has a normal human tolerance for this sort of thing)
  2. Ghetto Kitty Island Split 7″ – featuring Chicken on a Raft, Of Montreal, Bart Davenport and The Minders.

Speaking of which, I understand that the latter EP is not exactly widely known, is totes OOP, and completists might dig Of Montreal‘s ”Epistle to a Pathological Creep (demo)”, so here it is ripped for your listening pleasure:

Ghetto Kitty Island Split 7" (2004)I recorded it with arecord, and edited it with Audacity.  The arecord command line (more for my reference than your interest) was:

arecord -D 'hw:CARD=CODEC,DEV=0' -V stereo -c 2 -f dat -d 900 ghettokittyisland.wav

which records 900 seconds of audio at DAT quality to the file ghettokittyisland.wav, while showing a simple text meter on the screen.