DIYstompboxes.com

DIY Stompboxes => Digital & DSP => Topic started by: blackbutterflyian on November 12, 2012, 06:39:25 PM

Title: Looking to build a small digital box that plays back a single audio loop
Post by: blackbutterflyian on November 12, 2012, 06:39:25 PM
Hi guys,

I'm looking to build a digital music box that plays back a single audio loop. I've thought of cannibalizing an existing looping pedal that can store loops and mating with a cigarette box amp but there must be a cheaper (if not time consuming) way to do this. It will take a good while to get up to speed on everything that is involved but I'm patient and inspired!

I don't need to record directly into this device. I only need it to play back something I've recorded. I don't need it to store multiple loops either.

If anyone can steer me in a good direction I would be really, really grateful.

Thanks,
Ian
Title: Re: Re: Looking to build a small digital box that plays back a single audio loop
Post by: slacker on November 13, 2012, 03:17:02 AM
The easiest and cheapest thing to do is probably to buy a £10 MP3 player and stick that in a box with an LM386 based amp. In fact depending on how loud you want it to be you might not even need the amp.
Title: Re: Looking to build a small digital box that plays back a single audio loop
Post by: blackbutterflyian on November 13, 2012, 07:51:12 PM
Thanks Ian!

That does make a lot of sense and that should get me going very quickly.
Title: Re: Looking to build a small digital box that plays back a single audio loop
Post by: PRR on November 22, 2012, 11:36:06 PM
The other, bad, option is to get one of those greeting cards (or stuffed animals or books) that records a message from grandma to the kids. Press a hidden button, it records for 20 seconds. Press the main button, it plays back.

The only easy signal input is via a 3-cent microphone. (Output may be another hassle.) There's about 2 cents of digital storage. The fidelity is awful. They are not meant to playback looping (though jamming the Play button *may* work). And funny enough, they are awful hard to find at the right price WHEN you need one. Several places sell cards books bears for $30-$90 every day. Once in a while they go to surplus, but never when you need it.

Ian's cheap MP3 is probably a FAR better place to start. Unless you happen to have a recording-bear sitting unloved in the closet.
Title: Re: Looking to build a small digital box that plays back a single audio loop
Post by: Processaurus on November 26, 2012, 06:36:33 AM
Not as cheap as the $10 MP3 player, but I've been tempted to pick up the Sparkfun MP3 Trigger (https://www.sparkfun.com/products/11029?) for specialized projects that need to translate an electrical pulse to playing an MP3.
Title: Re: Looking to build a small digital box that plays back a single audio loop
Post by: egasimus on November 27, 2012, 02:14:47 PM
In case you're comfortable with programming AVRs, this comes to mind:
http://elm-chan.org/works/sd8p/report.html
This guy's a genius. I've built the music box from his site (basically, a six-voice wavetable synth squeezed into a chip with 2k of flash memory) for a friend - works like a charm!

Also, check this one out: http://txyzinfo.blogspot.com/2012/11/AVR-attiny2313-wav-music-player-from-SD-card-microSD-MMC.html

Try googling "attiny wav player" yourself, there's a thing or two that might pique your interest.