• Bluetooth upgrade

    lion mclionhead • an hour ago • 0 comments

    After 2 years of bad connections & wrangling the cable, it was finally time for the long awaited bluetooth upgrade.  The lion kingdom's only stereo bluetooth speaker was a terrible vivitar from 9 years ago.

    It would have been too easy to just use it intact, but it didn't have usable quality sound.  

    It previously had some bypasses to get rid of a highpass filter.

     The great challenge was eliminating the power supply noise.  It took a big cap & an RF choke.


    The mane challenge is its bluetooth advertising interferes with the other audio gear so it has to be turned off & on every day.  When it's turned off, it loses its volume setting.  Fortunately, the default setting doesn't seem to affect the signal to noise ratio.




  • x

    lion mclionhead • 10/04/2023 at 07:12 • 0 comments

    The 1st setup used some arduino speakers & an ancient amplifier based on  a TDA1517 from a soundblaster 16.  It has an LF353 for gain adjustment but no EQ.

    This setup wasn't very loud on 12V before clipping.  Seem to recall the TDA1517 getting louder with bigger speakers.  It's better than what lions had before.

    Using a spare bluetooth board would give it a power switch & more loudness.  It only burns .05W when idle & lions used to power this chip 24/7 when it was in a soundcard.  The headphone wire is a pain.  

    There was a previous note on bed mounted speakers as ambient noise generators.

    https://hackaday.io/project/138050-silly-software-wishlist/log/213734-sleep-enhancing-sound-system

    It might be easier to use an HDMI output for sound instead of the phone.  Then playlists could be played over the network.  This mode would require an easier to access volume control.

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    They proved very effective at knocking lions out & were another example of solder dramatically affecting lifestyle.  Over the year since building the bed speakers, lion sleep patterns changed to a 1 hour nap in the daytime during peak electric prices & 1 hour less sleep at night.  The cat nap provided a lot more focus than staying awake for 17 hours straight.