4 ms·

Am I understanding that this project is limited to play 8kHz samples wave-files, ie only up to 4kHz real world? Is that even tape-quality? Not to talk down any

Am I understanding that this project is limited to play 8kHz samples wave-files, ie only up to 4kHz real world? Is that even tape-quality? Not to talk down anyone’s hobby project, but that kinda limits the appeal for most other people I would think?

duped 2y ago
That's the (lowest) sample rate on telephone networks, so no. Way worse than tape.
- 6stringmerc 2y ago
  Was giving this thought as well and realized this is more in line with building a “crystal radio” type project than aiming for a marketable product. It’s a case study of a learning process, which is pretty spiffy to me.
smitelli 2y ago
Analog tape can sound pretty damn good, depending on the total surface area used and how fast it moves past the record/play heads.
- vetrom 2y ago
  Isn't there some way you could calculate the signal density you'd need in any of PDM/PWM/PCM to roughly equate to the quality of signal reproduction of a given tape media, given known tape surface/speed/magnetic density? It turns out there is https://www.electricity-magnetism.org/magnetic-storage-devices/ https://www.electricity-magnetism.org/magnetic-storage-devic... -- its a bit more complicated than what I'm more familiar with, which is film-grain-to-digital-equivalent resolution. Anyway, you could do the work to work out the bit depth/signal rate you'd need to equate to reproduction of a given fluxdensity/recording rate. I would bet the numbers for classic PCM/PDM devices line up surprisingly close to certain tape systems. On the flipside, once you know those numbers, you could also calculate what the expected analog equivalents could be, sample existing analog media/playback systems and use those to systematically characterize their quality, instead of going by earfeel, as it were.
relwin 2y ago
I've got a Pico 2 (2035) playing mono 22kHz MP3 using built-in 12-bit PWM, sounds pretty good. This would probably work on the 2040. However, as this is C code I'm not sure if this ports to MicroPython easily.

duped 2y ago

That's the (lowest) sample rate on telephone networks, so no. Way worse than tape.

6stringmerc 2y ago
Was giving this thought as well and realized this is more in line with building a “crystal radio” type project than aiming for a marketable product. It’s a case study of a learning process, which is pretty spiffy to me.

smitelli 2y ago

Analog tape can sound pretty damn good, depending on the total surface area used and how fast it moves past the record/play heads.

vetrom 2y ago
Isn't there some way you could calculate the signal density you'd need in any of PDM/PWM/PCM to roughly equate to the quality of signal reproduction of a given tape media, given known tape surface/speed/magnetic density? It turns out there is https://www.electricity-magnetism.org/magnetic-storage-devices/ https://www.electricity-magnetism.org/magnetic-storage-devic... -- its a bit more complicated than what I'm more familiar with, which is film-grain-to-digital-equivalent resolution. Anyway, you could do the work to work out the bit depth/signal rate you'd need to equate to reproduction of a given fluxdensity/recording rate. I would bet the numbers for classic PCM/PDM devices line up surprisingly close to certain tape systems. On the flipside, once you know those numbers, you could also calculate what the expected analog equivalents could be, sample existing analog media/playback systems and use those to systematically characterize their quality, instead of going by earfeel, as it were.

relwin 2y ago

I've got a Pico 2 (2035) playing mono 22kHz MP3 using built-in 12-bit PWM, sounds pretty good. This would probably work on the 2040. However, as this is C code I'm not sure if this ports to MicroPython easily.