CHG-0021: A New Sound Card for the Turntable

Date2026-10-13
Change typeConfiguration
StatusComplete
Systemsnpagent on the agent Pi (np-relay)
Howmake -C deploy/relay turntable DEVICE=plughw:CODEC
RiskLow. One line of the agent’s settings, and a restart of the agent
DecisionsADR-0021
RelatedCHG-0013, which named the first input; CHG-0019, since which only a record lights the stand

Summary

The sound card the turntable is heard through was replaced with another USB adapter. The agent was still told to listen to the old one by name, plughw:UA4FX, which was no longer there, so the turntable’s driver heard nothing and reported nothing. With the stand lit for records only, that was a stand that did nothing for a record.

Procedure

  1. make -C deploy/relay status, to see what the Pi had: the turntable’s line said plughw:UA4FX is not plugged in, and listed the cards present. The new one is CODEC.
  2. make -C deploy/relay turntable DEVICE=plughw:CODEC.

Verification

  • status says listening to plughw:CODEC.
  • The agent names what is playing, and nowplaying/current is the turntable’s.

Undo

make -C deploy/relay turntable DEVICE=plughw:UA4FX, with that card back.

Outcome

When (UTC)What happened
21:20The turntable was switched on: the beacon said so, and the stand was sent its dim scene. A record played and, by its owner’s account, the lights did not respond.
21:25status: plughw:UA4FX is not plugged in, arecord unable to open it, and the cards present were Headphones, vc4hdmi0, vc4hdmi1 and CODEC. iTunes’ computer was not answering either.
21:25The input was set to plughw:CODEC and the agent restarted.
21:26The agent said it was playing The Doors, “The WASP (Texas Radio And The Big Beat)”, from L.A. Woman; nowplayd made it current with the sleeve from the owner’s collection; the stand reported a chase in four colors at 0.8. iTunes’ driver came online in the same minute, stopped.

Departures

  • Done before it was written down, at the owner’s suggestion that the Pi needed something for the new adapter.

Follow-ups

  • The new card’s level in a gap between tracks has not been measured. The driver takes a gap to be quieter than -55 dBFS (ADR-0026), and that was a number for the old card.
  • A card’s ALSA name changes with the card. Nothing says so until status is read; the driver’s turntable.capture_lost event is in the log store, and no dashboard shows it.