High resolution files on old DACs?

[Barry_Sound]

What happens when I feed an older DAC (16 bit / 44,1 kHz) a higher signal through USB? Downsampling? No sound? Sound but some sort of jitter?

 

[Jimbob54]

What happens when I feed an older DAC (16 bit / 44,1 kHz) a higher signal through USB? Downsampling? No sound? Sound but some sort of jitter?

Likely the source will recognise the limitation and downsample.

 

[gvl]

What happens when I feed an older DAC (16 bit / 44,1 kHz) a higher signal through USB? Downsampling? No sound? Sound but some sort of jitter?

There’s no universal answer. What DAC specifically?

 

[AnalogSteph]

What happens when I feed an older DAC (16 bit / 44,1 kHz) a higher signal through USB?

1. The USB interface will tell the host exactly which formats it supports, and will not accept anything outside of that.
2. Something with a USB interface isn't terribly old in the grand scheme of things to begin with.

 

[unpluggged]

Likely the source will recognise the limitation and downsample.

Or will not play. Depends on source.

Something with a USB interface isn't terribly old in the grand scheme of things to begin with.

I think it's more about supported formats rather than literal age

 

[gvl]

I suspect the OP is confused as even early USB DACs usually supported up to 96khz/24bits. For the purpose of keeping this clear and to avoid future confusion he needs to tell us exactly what DAC he has in mind and how it will be connected to the source (a PC?).

 

[Barry_Sound]

I was asking because of a 20 year old Perreaux DAC. I read somewhere it will only support CD quality max however the manual states 192kHz/24-bit.

 

[voodooless]

Sound but some sort of jitter?

Jitter is generally not something you can hear unless it is extremely severe. Coincidentally, these ancient USB codecs did not support asynchronous USB transfers and derived their clocks from the 12 MHz USB clock. This resulted in significantly more jitter than you see in modern asynchronous codecs. Especially when playing 44.1 kHz content exaggerates this effect. Audibility of this is however questionable, but in this case not totally out of the realm of possibility.

This however, has nothing to do with high sample rate source. As other have pointed out, generally the player or operating system will accommodate sample rate conversion. If indeed such an old codec is used, I would recommend setting it to 48 kHz for best performance.

 

[Chrispy]

I was asking because of a 20 year old Perreaux DAC. I read somewhere it will only support CD quality max however the manual states 192kHz/24-bit.

I'd go with the manual.

 

[voodooless]

I was asking because of a 20 year old Perreaux DAC

Can you narrow it down?

 

[audio_tony]

I was asking because of a 20 year old Perreaux DAC. I read somewhere it will only support CD quality max however the manual states 192kHz/24-bit.

If it's the DP32 then it should support 192k / 24 bit via USB

If you're using it with Windows, chances are the default rate is 44k/16bit.

Does it have an ASIO or WASAPI driver?

perreaux

perreaux.com

 

[LTig]

I suspect the OP is confused as even early USB DACs usually supported up to 96khz/24bits. For tor purpose of keeping this clear and to avoid future confusion he needs to tell us exactly what DAC he has in mind and how it will be connected to the source (a PC?).

Yep, my really old Edirol UA25 sound interface supports 96/24 even with a USB 1 port. The Musical Fidelity V-DAC however supports only 44/24 and 48/24 via USB, at least with my Linux PC.

 

[kemmler3D]

I was asking because of a 20 year old Perreaux DAC. I read somewhere it will only support CD quality max however the manual states 192kHz/24-bit.

I'd tend to trust the manual...

Either way you are unlikely to run into a situation where the sound quality would be harmed in a subtle way. IME failures in resampling are pretty obvious. Either it will play fine or it will output something obviously wrong.

 

[audio_tony]

Yep, my really old Edirol UA25 sound interface supports 96/24 even with a USB 1 port. The Musical Fidelity V-DAC however supports only 44/24 and 48/24 via USB, at least with my Linux PC.

EDIT: I just realised you have version 1 of the DAC and I've quoted specs for version II.

According to the spec for the USB port is should support 24/96:
1x USB type ‘B’ connector for computer/PDA - 16-24 bits, 32-96 kbps (Determined by source file/computer settings)

If you run the 'alsa-capabilities' script from here => https://gitlab.com/sonida/alsa-capabilities

What modes are reported?

For example, this is what is reported for a USB2 (CM6631A) interface I have.

0) USB Audio Class Digital alsa audio output interface `hw:0,0'
- device name = USB2.0 High-Speed True HD Audio
- interface name = USB Audio
- usb audio class = (n/a)
- character device = /dev/snd/pcmC0D0p
- encoding formats = S32_LE, S16_LE, S24_3LE
- monitor file = /proc/asound/card0/pcm0p/sub0/hw_params
- stream file = /proc/asound/card0/stream0


To see what formats your device supports, look for the "stream file" entry and then type:

cat /proc/asound/cardX/streamX (where 'X' is the number of your device / card ) and then look for the "Rates" entry in the resulting output.

Rates: 44100, 48000, 88200, 96000, 176400, 192000, 352800, 384000

 

[gvl]

I was asking because of a 20 year old Perreaux DAC. I read somewhere it will only support CD quality max however the manual states 192kHz/24-bit.

If it’s the SXD2 then yes, USB is 16 bits max 48khz sampling. If you play hires material over direct USB connection to the DAC it will be downsampled to a format supported by the DAC, it should play w/out issues then. You could however use a modern USB to SPDIF adapter with this DAC and avoid downsampling as it supports up to 192kHz/24bits over coax. The specs are kind of meh by todays norms, so idk if it matters downsampled or not, as long as downsampling is correctly done.

 

[Barry_Sound]

If it’s the SXD2 then yes, USB is 16 bits max 48khz sampling. If you play hires material over direct USB connection to the DAC it will be downsampled to a format supported by the DAC, it should play w/out issues then. You could however use a modern USB to SPDIF adapter with this DAC and avoid downsampling as it supports up to 192kHz/24bits over coax. The specs are kind of meh by todays norms, so idk if it matters downsampled or not, as long as downsampling is correctly done.

View attachment 416460

Thanks, its that DAC. The manual doesnt tell much, apparently USB is limited compared to Coax.

 

[voodooless]

Thanks, its that DAC. The manual doesnt tell much, apparently USB is limited compared to Coax.

Yeah, PCM2902… that’s one of the ancient USB codecs.

Note that there is also a SRC4193 asynchronous sample rate converter to upsample. This will probably get rid of most of the jitter.

I’d say, if it sounds good, enjoy!

 

[gvl]

Thanks, its that DAC. The manual doesnt tell much, apparently USB is limited compared to Coax.

The spec page I attached is from the manual, it pretty much tells everything you need to know.

 

[gvl]

Yeah, PCM2902… that’s one of the ancient USB codecs.

Note that there is also a SRC4193 asynchronous sample rate converter to upsample. This will also got rid of most of the jitter probably.

I’d say, if it sounds good, enjoy!

There are some interesting claims in the manual such as that the DAC is able to lower quantization noise of 16-bits by upsampling to 24-bits and achieve 144dB dynamic range and them being able to preserve original samples by integer 4x upsampling, which I say is BS because of that ASRC.

 

[voodooless]

There are some interesting claims in the manual such as that the DAC is able to lower quantization noise of 16-bits by upsampling to 24-bits and achieve 144dB dynamic range and them being able to preserve original samples by integer 4x upsampling, which I say is BS because of that ASRC.

It has an 80 SINAD, I wouldn't worry about any of that