https://www.reddit.com/r/headphones/?f=flair_name:"DIY/Mod"
I'm trying to gauge interest in an open-source project. The basic idea is to use a Raspberry Pi as a stand-alone DAC + PEQ + (optional) headphone amp. You'd be able to not only adjust the DSP settings via a browser, but you'd be able to have knobs on the device for physical adjustment -- volume, balance, bass shelf gain, etc. In theory, you might have up to 8 knobs or 5-6 knobs + push switches. Sure, there are base presets for my headphones, but I grew up in an era with bass and treble knobs, not to mention balance knobs and there are times that I'd really like to trivially adjust things. A bass shelf, treble shelf, the "air" or ear-gain region, etc. Like the Quedelix 5k, you might have a range of presets ("spk" in their lingo) and then use the knobs to add other adjustments ("usr" in their lingo). Feeling like a bit more of a bass shelf on this song or today? Dial that up. Balance got you a touch off now? Adjust that knob.
This leans heavily on CamillaDSP and so far, it's doing its DSP goodness, driving headphone or RCA outputs, rotary encoder knobs are making adjustments to not only volume but DSP settings, playing from local files, network files, or Airplay, etc. It'll hopefully have full USB pass-through (others have this working already -- part on the way), a nice enough interface / configuration to let you customize the what tweaks the knobs do to DSP, etc. The Pi4 is about $50, the DAC board another $20, toss in some encoders and misc parts and you're looking at $100 for a stand-alone DAC w/full PEQ with as many bands and settings as you like.
The Q is - is this the kind of thing that anyone else is interested in and seeing discussed here? Or, is this just a "me" thing? If so, what kind of features would you want available? What would you want physical knobs to be able to adjust? If not, I'll tinker and still put it up on GitHub, but be less fastidious about making others able to easily understand and replicate.
I'm trying to gauge interest in an open-source project. The basic idea is to use a Raspberry Pi as a stand-alone DAC + PEQ + (optional) headphone amp. You'd be able to not only adjust the DSP settings via a browser, but you'd be able to have knobs on the device for physical adjustment -- volume, balance, bass shelf gain, etc. In theory, you might have up to 8 knobs or 5-6 knobs + push switches. Sure, there are base presets for my headphones, but I grew up in an era with bass and treble knobs, not to mention balance knobs and there are times that I'd really like to trivially adjust things. A bass shelf, treble shelf, the "air" or ear-gain region, etc. Like the Quedelix 5k, you might have a range of presets ("spk" in their lingo) and then use the knobs to add other adjustments ("usr" in their lingo). Feeling like a bit more of a bass shelf on this song or today? Dial that up. Balance got you a touch off now? Adjust that knob.
This leans heavily on CamillaDSP and so far, it's doing its DSP goodness, driving headphone or RCA outputs, rotary encoder knobs are making adjustments to not only volume but DSP settings, playing from local files, network files, or Airplay, etc. It'll hopefully have full USB pass-through (others have this working already -- part on the way), a nice enough interface / configuration to let you customize the what tweaks the knobs do to DSP, etc. The Pi4 is about $50, the DAC board another $20, toss in some encoders and misc parts and you're looking at $100 for a stand-alone DAC w/full PEQ with as many bands and settings as you like.
The Q is - is this the kind of thing that anyone else is interested in and seeing discussed here? Or, is this just a "me" thing? If so, what kind of features would you want available? What would you want physical knobs to be able to adjust? If not, I'll tinker and still put it up on GitHub, but be less fastidious about making others able to easily understand and replicate.
There does seem to be interest in multi-channel dac and DSP units for speaker builders. High quality units can be costly though, and not all of them are necessarily as good as some folks would like.
Regarding RPi, it has been a source of jitter on the GPIO bus (although a dac which as can as I2S clock master can get around that), and a source of radiated and conducted EMI/RFI that has been demonstrated to affect attached dac sound. Some of the accessories Iancanda makes are specifically to deal with those types of problems. Using it as a USB host probably makes more sense in terms of dealing with noise problems, but building a good USB dac can get a bit complicated and more costly than a hat dac.
Regarding RPi, it has been a source of jitter on the GPIO bus (although a dac which as can as I2S clock master can get around that), and a source of radiated and conducted EMI/RFI that has been demonstrated to affect attached dac sound. Some of the accessories Iancanda makes are specifically to deal with those types of problems. Using it as a USB host probably makes more sense in terms of dealing with noise problems, but building a good USB dac can get a bit complicated and more costly than a hat dac.
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