What? 32Bit 384KHz dac? And for 50 bucks? what the $*#%@? 2015-04-23 12:43 GMT-03:00 Charles Z Henry <[email protected]>:
> It's already started.... 32bit DACs are available from AKM and XMOS, > for example. Although I don't know what software/hardware platform > you'd use to actually make use of this precision, you can build your > own 32-bit sound playback interface with a few boards from HK: > > http://www.yuan-jing.com/dacs-decoder/32bit-192khz-usb-dac-decoder-ak4399-wm8805-pcm2706-opa627au-optical-coaxial > > http://www.yuan-jing.com/dacs-decoder/xmos-usb-audio-32bit-384khz-dac-decoder-board-pcm5102-tda1308-headphone-amp > > > On Thu, Apr 23, 2015 at 9:41 AM, Alexandre Torres Porres > <[email protected]> wrote: > > Yep, nice indeed, I guess I learned - in short and in layman's undetailed > > terms - that audio output is ~24bits (a bit higher, but much higher for > > smaller numbers). > > > > Moreover, digital audio cards won't likely have more than 24 bit > precision > > for many years to come, so it's just way more than enough. > > > > thanks > > > > > > 2015-04-23 6:43 GMT-03:00 Julian Brooks <[email protected]>: > > > >> Nice. Thanks Chuck, I learnt something. > >> > >> On 22 April 2015 at 23:45, Charles Z Henry <[email protected]> wrote: > >>> > >>> On Wed, Apr 22, 2015 at 5:11 PM, Alexandre Torres Porres > >>> <[email protected]> wrote: > >>> > >>> > So I start with this idea that the audio (values from -1 to 1) can't > be > >>> > in > >>> > full 32 bit float resolution, it's less. I don't see why that is > >>> > "wrong". > >>> > And then, from it, my first question here was: "what is the audio > >>> > resolution > >>> > then?". I'm still clueless here about this answer. > >>> > > >>> > Moreover, is it more or less than what 24 bit audio cards handle? > >>> > >>> Let me try: > >>> > >>> 32-bit floating point numbers have 24 bits of precision. Always. The > >>> remaining 8 bits are just for the sign and exponent. When the > >>> amplitude of the signals decrease, you don't lose any precision in > >>> floating-point. The value of the least significant bit (LSB) gets > >>> proportionally smaller. > >>> > >>> However, the output of a 24-bit soundcard always has a fixed > >>> quantization. The LSB is always the same size. Smaller numbers have > >>> less precision. > >>> > >>> The mismatch occurs when converting from the 32-bit floats to the > >>> 24-bit fixed point numbers. Now, the smaller numbers aren't as > >>> precise anymore. They get rounded to the nearest number in the 24-bit > >>> fixed point system. > >>> > >>> So, yes, the resolution (of small numbers) in floating point (internal > >>> to Pd) is finer than the resolution of those numbers when output > >>> (driver/DAC). > >>> > >>> Also, the 24-bit fixed point format is for values between -1 and 1. > >>> That means that numbers between 0 and 1 have just 23 bits. In 32-bit > >>> math, the numbers between 0.5 and 1 still have 24 bits of precision > >>> (the sign is held elsewhere). That means that Pd's internal > >>> resolution is finer than the soundcard resolution for all numbers > >>> between -1 and 1. > >>> > >>> Chuck > >>> > >>> _______________________________________________ > >>> [email protected] mailing list > >>> UNSUBSCRIBE and account-management -> > >>> http://lists.puredata.info/listinfo/pd-list > >> > >> > > >
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