HPR3507: USB Turntable fix and sound journey

Hacker Public Radio

Partial list of albums

• Journey - Frontiers
• Journey - Evolution
• Journey - Greatest Hits
• Journey - Departure
• Chicago - 2 albums - unknown titles
• John Denver - Rocky Mountain Christmas
• Inside Star Trek (1976)
  • SIDE I Inside Star Trek Star Trek Theme William Shatner Meets Captain Kirk The Origin of Spock Sarek's Son Spock The Questor Affair
  • SIDE II The Enterprise Runs Aground McCoy's Rx for Life The Star Trek Philosophy Asimov's World of Science Fiction A Letter From a Network Censor The Star Trek Dream Ballad I/Ballad II)*

Inside Star Trek album: Cover

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Inside Star Trek album: Contents

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I found a turntable at the thrift store, and the spindle ran, but the platter did not. The belt had slipped off, and here is the fix.

• https://www.youtube.com/watch?app=desktop&v=rXkOoaIVsvE

How to remove platter

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Belt placement

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Routing Audio from a USB Turntable to HDMI using a Raspberry Pi

• https://www.rickmakes.com/routing-audVmmsio-from-a-usb-turntable-to-hdmi-using-a-raspberry-pi

Send input to output

alsaloop -t 500000 -C hw:CARD=CODEC,DEV=0 -P default:CARD=b1

alsaloop man page

• https://linux.die.net/man/1/alsaloop

  -t | --tlatency= Requested latency in usec (1/1000000sec).

Parameter b1 is found by

pi@retropie:~ $ aplay -l **** List of PLAYBACK Hardware Devices **** card 0: b1 [bcm2835 HDMI 1], device 0: bcm2835 HDMI 1 [bcm2835 HDMI 1]

Raspberry Pi as a USB audio capture device

• https://scruss.com/blog/2012/11/20/raspberry-pi-as-a-usb-audio-capture-device

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

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

Used hw:CARD=CODEC,DEV=0 derived from 'arecord -L'

hw:CARD=CODEC,DEV=0 USB Audio CODEC, USB Audio Direct hardware device without any conversions

arecord man page

• https://linux.die.net/man/1/arecord

 -D, --device=NAME Select PCM by name -V, --vumeter=TYPE Specifies the VU-meter type, either stereo or mono. The stereo VU-meter is available only for 2-channel stereo samples with interleaved format. -c, --channels=# The number of channels. The default is one channel. Valid values are 1 through 32. -f --format=FORMAT Sample format Recognized sample formats are: S8 U8 S16_LE S16_BE U16_LE U16_BE S24_LE S24_BE U24_LE U24_BE S32_LE S32_BE U32_LE U32_BE FLOAT_LE FLOAT_BE FLOAT64_LE FLOAT64_BE IEC958_SUBFRAME_LE IEC958_SUBFRAME_BE MU_LAW A_LAW IMA_ADPCM MPEG GSM SPECIAL S24_3LE S24_3BE U24_3LE U24_3BE S20_3LE S20_3BE U20_3LE U20_3BE S18_3LE S18_3BE U18_3LE Some of these may not be available on selected hardware The available format shortcuts are: -f cd (16 bit little endian, 44100, stereo) [-f S16_LE -c2 -r44100] -f cdr (16 bit big endian, 44100, stereo) [-f S16_BE -c2 -f44100] -f dat (16 bit little endian, 48000, stereo) [-f S16_LE -c2 -r48000]

Recording to FLAC

• https://unix.stackexchange.com/questions/583892/how-can-one-record-mic-audio-straight-to-a-flac-file

How can one record mic audio straight to a FLAC file?

ffmpeg -f alsa -ar 48000 -ac 1 -i hw:0 testfile.flac

Took out the "-ac 1", which downmixed the input to mono

Change hw:0 to hw:2 based on

pi@retropie:~/vinyl $ arecord -l **** List of CAPTURE Hardware Devices **** card 2: USB20 [AV TO USB2.0], device 0: USB Audio [USB Audio] Subdevices: 1/1 Subdevice #0: subdevice #0 ffmpeg -f alsa -ar 48000 -i hw:2 testfile_stereo.flac

FFmpeg Audio Channel Manipulation

• https://trac.ffmpeg.org/wiki/AudioChannelManipulation