Compatible I2S source devices

Ted Smith said

Personally I don’t like any sample rate conversion before the DS


Isn’t that what the bridge is doing by downsampling the 128, 256 and 512 times DSD to 2.8224MHz? Wouldn’t it be better to feed these formats directly through the I2S connection if you have a full DSD streamer? Can you make the BridgeII ready for higher sample rates?

Cable-guy said
Ted Smith said Personally I don't like any sample rate conversion before the DS

Isn’t that what the bridge is doing by downsampling the 128, 256 and 512 times DSD to 2.8224MHz? Wouldn’t it be better to feed these formats directly through the I2S connection if you have a full DSD streamer? Can you make the BridgeII ready for higher sample rates?


As I’ve stated before IMO if you have to use sample rate conversion (or chose to) before an input to the DS, I’d convert DSD to PCM (say, 24 or 32 / 352.8k (or 24/176.4k for the bridge)) unless you know for a certain that the eternal DSD to DSD converter does all of it’s processing at the sample rate of the higher DSD rate. As always tho, things like this are personal preference and you should pick which ever method that gives you the sound you like the best.

Ted, I do get your comment about sample rate conversion, particularly down sampling DSD and making sure that the process is done at a rate at least equal to the higher sample rate. I do have one question about your comment. You suggest down sampling DSD 128 or higher to 176.4k. Is it of particular significance to keep the rate change ratio an integer value, or would down sampling to 192k be as good an option? I suppose that part of the answer depends on the resampling algorithms, but is there a more generic answer. Perhaps it is just easier and safer to keep the ratio to a power of two integer value.

Thanks in advance, and I look forward to yet more enlightenment and education. Brilliant engineers who can also communicate clearly to less educated tech and non-tech types are a rare breed and a treasure to share space with.

J.P.

Short answer: going to 192k can be done as well as 176.4k, but the code is much harder to write from first principles and more complicated if written naïvely. I.e. there are a lot more broken (or poorly implemented) 192k downsamplers out there than 176.4k downsamplers.

More detail:

In the abstract there exist arbitrarily accurate resampling algorithms from any rate to any other rate. But simple upsampling and downsampling by an integer is much easier both in the programming and the amount of arithmetic. If you want to avoid weird interpolation (which will introduce some distortion (tho limitable) the sanest way of upsampling and downsampling consists of finding LCM(in rate, out rate) (the least common multiple of the input and output sample rates), zero stuffing the input to get to that sample rate, filtering to half of the lowest of the incoming and outgoing sample rates and throwing away all but 1 sample for each LCM(in rate, out rate) / samples. (Then there’s the significant optimization of not doing the multiplies for the incoming zeros and not calculating the filter outputs that you’ll be throwing away.) Here’s a medium level lecture about this: https://www.youtube.com/watch?v=qca4jIoxDtY

In the case of your question that means that going from DSD 128 down to 176.4k is a simple filter keeping up to 88.2k and throwing away all but 1 in 32 samples (obviously you don’t need to calculate the samples you’ll be throwing away). To get to 192k you need to upsample to 28.224MHz ( = 10 x the DSD64 rate, sound familiar?), filter keeping up to 96k and then downsample by 147 to 192k. The difference is that the 2nd path clearly requires five times the math for a naïve implementation or much more careful coding for an implementation that doesn’t do any multiplies for the incoming 0’s or the unused outputs. Both can be done with the same amount of math if you are careful, but the chance for bugs in the 2nd case is a lot higher.

Thank you Mr. Wizard for that informative response. You confirmed my thoughts on subject and elaborated nicely, adding to my understanding of it. I have not yet watched the video, but do intend to. I just need to block off a chunk of time to do it justice.

Are you able and willing to offer an opinion on the commonly discussed products (J River, Foobar2000, MinimServer/MinimStreamer, …) and the quality of their sample rate conversion software? I understand and accept if you choose not to offer specific opinion on products, mostly just curious.

J.P.

I know that JRiver added SOX based filters in release JRiver MC 22 ( (or something like that)) which is a good implementation.

Similarly you can find foobar2000 plugins for resampling based on SOX and dBpoweramp’s SSRC (both probably better than the older PPHS implementation)

I don’t know anything about Minim…

Things are a little more complicated when DSD is added to the mix - there I definitely suggest at least trying the DSD to 24/176.4 options available rather than relying on less well documented DSD to DSD converters (or even PCM to DSD converters.)

On the MAC I would trust BitPerfect’s conversion to DSD to do a good job, you can test for yourselves whether you’d like to use it compared to using the DS’s versions.

Many people speak highly of HQPlayer, since it’s redundant with things I use I haven’t tried it or looked at its documentation about it’s algos.

In all cases the differences can be small enough that it’s pure personal preference which paths you’d like to use. I can say that the DS’s filters for PCM don’t alias and have as wide of bandwidth as practical to be at -144dB at the Nyquist frequency. Some prefer slower rolloffs for “simpler” music (by simpler I mean a small number performers/sources, not a statement about the music itself.)

Wow. Thanks again for the wealth of information. I hope that we are not boring anyone. For myself, I am thoroughly enjoying this lesson / discussion.

Curiosity assuaged, I will say that even before this day of lessons I would have been strongly inclined to go with integer ratio sample rate changes where possible or practical, for exactly the reasons that you indicated. Still, this is not for naught as I have come out of this with a bit more knowledge and understanding of the subject. I hope that others here have also benefitted from this discussion.

I am glad to hear that dBpoweramp is likely good quality, as that is my primary tool for sourcing digital files for my library. Of course, 99.9% of the time it is just used for ripping CDs, but knowing that it should be good for quality sample rate conversion is comforting to know should said function become necessary. I’ll have to look into plugins for Foobar2000 and check up on MinimStreamer’s conversion tools to make sure that I have all bases covered.

J.P.

Linvincible said
Holzohr said Just found this, for the pi guys that are neither soldering quarter-gods Mano Music Streamer

for that price, man the enclosure must be expensive! what they do is the same as a Pi + Kali or digi+ reclocker (except they use different clocks)

and they don’t provide IR remote capabilities

you can do that yourself without any soldering for a quarter of the price

Here a review from German HIFI Statement net magazine (translated by Google) Magna Hifi Mano Music Streamer

Holzohr said

Here a review from German HIFI Statement net magazine (translated by Google) Magna Hifi Mano Music Streamer

I was looking for a solution to play native DSD via I2S and found this thread.

I own a Mano streamer and it sounds great It runs DSD64 and DSD128 without any problem.

Its a complete product and the support is great!

ps. They do offer IR remote capabilities

RaspTouch LVDS - Streamer I2S HDMI Audio-GD Compatible IIS

Holzohr said

RaspTouch LVDS - Streamer I2S HDMI Audio-GD Compatible IIS


That looks pretty good. Are you getting one?

If so, please report back on the sound quality.

Holzohr said

RaspTouch LVDS - Streamer I2S HDMI Audio-GD Compatible IIS


I didn’t follow the whole discussion, but may I ask what’s the reason for you (as you own a Bridge II) to look for an I2s compatible streamer? Just for DSD128? So far I would have expected that the superior coupling of the bridge by the lens interface usually beats all external solutions except the DMP which has an even better interface.

yacheah said

That looks pretty good. Are you getting one?

If so, please report back on the sound quality.


I find interesting the RaspTouch Streamer comes with the Kali reclocker board. That should make it superior but I will remain with my pi3 solution for the moment, with the Audio-GD I2S-to-HDMI module and a HiFiBerry DAC+ Pro in-between. For the ‘now playing’ screen I use my good old Squeezebox Touch.

jazznut said

I didn’t follow the whole discussion, but may I ask what’s the reason for you (as you own a Bridge II) to look for an I2s compatible streamer? Just for DSD128? So far I would have expected that the superior coupling of the bridge by the lens interface usually beats all external solutions except the DMP which has an even better interface.


I am still a Squeezebox guy and I love tinkering now and then and that I can use such a solution (even DSD128-ready now) via I2S. To be honest I sold my first Bridge II (in pre Roon times). Now with Roon it’s a different story and I am happy with the Bridge II. Though I prefer Roon (especially via the Bridge II) for listening I won’t quit the Squeezebox plattform. The sq of this rather el-cheapo solution is surprisingly well. The DS DAC should have more I2S-inputs… instead of SPDIF… imho.

I think the only unique thing is the case with built in touch screen. I think you can buy everything else on your own. They offer a good deal on a linear power supply, but it is out of stock. And it is using generic software.

If you have a tablet, I would price the other boards, the Raspberry Pi3 is around $35. Does anyone know the price of the Allo Kali board?

Appr 75 Euro for their linear power supply is a very good deal, to the best of my knowledge.

It would be nice to get a copy of either Bryston or Audio Alchemy’s firmware. That would give you a better player than the ones available, as far as I am aware. I’m using Volumio without any other boards or linear power supply, I would like to add either the Hifiberry or Allo Kali, and a linear power supply, but then I wonder if the little Aries would be a better deal, as I still need a case. As is Volumio is only good for casual listening, using either a flash drive, or a USB hard drive.

Not to mention, I’m new to Linux.

Thanks for posting the Audiophonics link, more options;-)

I am still a Squeezebox guy and I love tinkering now and then and that I can use such a solution (even DSD128-ready now) via I2S. To be honest I sold my first Bridge II (in pre Roon times). Now with Roon it's a different story and I am happy with the Bridge II. Though I prefer Roon (especially via the Bridge II) for listening I won't quit the Squeezebox plattform. The sq of this rather el-cheapo solution is surprisingly well. The DS DAC should have more I2S-inputs.. instead of SPDIF.. imho.
I'm on Jriver with the Bridge II. Not sure what's better then for you (Roon/bridge or separate streamer/Squeezebox), as Roon is being told as worse sounding than Jriver on the Bridge (and probably other streamers, too).
Holzohr said

The DS DAC should have more I2S-inputs… instead of SPDIF… imho.


Oh no! My DSjr is fed by both my LAN and via TosLink from a Sonos Connect (aka ZP90). The former (via Roon) is my preferred way when settling to just listen to music because I can use hires sources. But for both my partner’s convenience and for myself when I’m not settled in front of the premium system we use Sonos (for Tidal, internet radio or our ripped music library). Sonos is convenient and mostly reliable and now that I’ve Ted Smith’s nominally jitter-insensitive DirectStream DAC technology the fact that the Sonos isn’t an audiophile source doesn’t make any difference. For 16/44·1 I can’t distinguish between Sonos or the internal Bridge. And I don’t need to think about galvanic isolation from that non-audiophile Sonos because I’m using an optical connection. So let’s keep the TosLink (and the co-axial) S/PDIF inputs.

I, too, would not want to give up the other inputs. But a few more I2S would be perfectly fine and I bet some would use them. Flexibility is always good.

Probably similar to others here, I currently use all my I2S inputs (including the Bridge which is I2S, but not HDMI); the two HDMI inputs being used for the DMP and the NPC. Should I want to get an Octave Server, I would have to us an alternative input for one of the sources or unplug one source and replace with the Octave. Not the best situation, but luckily I don’t plan on an Octave (or any other I2S source) at this point. The downside to all this is a new back panel would be required on the DS to accomodate the additional input(s), something that would be provided on a DS MkII or an all new model. No word from Paul on such a new beastie …

Just got my new and amazing DMP and DSD. Yeah, worth every dollar. So here is my first hurdle. I’m using the DSD as a preamp and have my TV cable going through TOSlink which is working to my satisfaction. I want to connect my OPPO BDP-105 for movies and Netflix only using its HDMI2 out to the I2S 2 input. Not getting any sound at all. I read at the begining of this thread a little about OPPO compatibility but is seemed to fizzle out. Am I going to have any success with this configuration?

Bruce L,

I am fairly certain that the Oppo HDMI out is configured for a different use other than I2S.

Does the Oppo have another digital out that you can connect to your DS?

If it only has toslink, you can use a converter to change it to SPDIF, since you have your CATV connected via toslink.