Dear all,
Some time ago I purchased a Cronus and Hermes for the RPI. I was unable to get is to work with Volumio.
I now stream via the Allo USBridge and a WaveIO to the BIIISE Pro.
I want to make use of the Cronus to potentially squeeze out the last bit of improvement.
For that I want to identify the Hermes I2s input headers to connect the WaveIO. I found this.
My plan is to simply connect the I2s output from the WaveIO to the input headers of the Hermes-RPI.
Can you advise me concerning my following questions?
1. Will this plan work?
2. The Hermes has several power input options. I will feed 5V to one of them. That would be the ‘dirty’ side but there is a ‘clean’ side on the Hermes as well. Does this side require a separate power source?
3. I cannot find that much information about the Cronus. I found a picture on the internet to tell me how to orientate the Crystal clocks. Have I setup the Cronus correctly?
4. Do I forget something to take into account?
Thank you for your expertise on this.
Jordo
Some time ago I purchased a Cronus and Hermes for the RPI. I was unable to get is to work with Volumio.
I now stream via the Allo USBridge and a WaveIO to the BIIISE Pro.
I want to make use of the Cronus to potentially squeeze out the last bit of improvement.
For that I want to identify the Hermes I2s input headers to connect the WaveIO. I found this.
My plan is to simply connect the I2s output from the WaveIO to the input headers of the Hermes-RPI.
Can you advise me concerning my following questions?
1. Will this plan work?
2. The Hermes has several power input options. I will feed 5V to one of them. That would be the ‘dirty’ side but there is a ‘clean’ side on the Hermes as well. Does this side require a separate power source?
3. I cannot find that much information about the Cronus. I found a picture on the internet to tell me how to orientate the Crystal clocks. Have I setup the Cronus correctly?
4. Do I forget something to take into account?
Thank you for your expertise on this.
Jordo
Attachments
Last edited:
No, probably not. RPi generates its own clocks in most cases. You can only have one master clock source (one clock domain, in other words), or else you have to use ASRC or FIFO buffering to interface with another clock domain (such as Chronus). Moreover, I tried Chronus and didn't like it very much, although it may have tended to sound a little better when I put it in steel case for shielding.
Regarding RPi, it can support an I2C master dac, where RPi serves as an I2S clock slave. That's one way to set it up to work with an external clock domain. The driver for Allo Katana dac puts RPi into I2S slave mode, for example. However in that mode you have to supply all BCLK and LRCK to RPi according to the clock frequencies it requests over I2C bus.
Anyway, the best way to use RPi with a dac is to use a good quality USB dac and let RPi be the USB host. RPi GPIO bus is pretty poor in comparison, but it can be cleaned up quite well if really desired. In that case, you probably bought the wrong stuff. An Iancanada FIFO_Pi and other Iancanada accessories can do it. That said, the cost for all the goodies can add up. In the end a good USB dac may make more sense.
Hi Markw4,
Thank you for your post.
Maybe the title is a bit deceptive but my intention is to omit the RPi but to use the Hermes Hat and Cronus. Instead of the RPi I want to feed the Luckit WaveIO I2S output signal as an input for the Hermes instead of what the RPi would do.
Cheers,
Jordo
Thank you for your post.
Maybe the title is a bit deceptive but my intention is to omit the RPi but to use the Hermes Hat and Cronus. Instead of the RPi I want to feed the Luckit WaveIO I2S output signal as an input for the Hermes instead of what the RPi would do.
Cheers,
Jordo
In that case you would need to use Chronus as the master clock for the WaveIO board. Does it support using an external master clock? Otherwise you would still have mixed clock domains.
The chain would look as follows:
Allo UBridge Sig—> WaveIO—>Hermes—>Cronus—>BIIISE Pro.
Isn’t it the Cronus’ core business to pick up the WaveIO’s clock and reclocking it? doesn’t that work with the clock signal in the 3 data lines? Would that require a 4th data line for the master clock?
Both boards have a Master Clock connection. Would I need to use these?
Allo UBridge Sig—> WaveIO—>Hermes—>Cronus—>BIIISE Pro.
Isn’t it the Cronus’ core business to pick up the WaveIO’s clock and reclocking it? doesn’t that work with the clock signal in the 3 data lines? Would that require a 4th data line for the master clock?
Both boards have a Master Clock connection. Would I need to use these?
No. A PLL could be used to pick up WaveIO's clock, but a crystal oscillator like Cronus uses can't to that. The purpose of Cronus is to be the one master clock for every part of the dac including for the USB board. Then it can clean up the I2S signals by reclocking them before they go to the dac.
Otherwise you need a way to bridge between WaveIO master clock domain, and Cronus master clock domain. The ways are basically PLL, ASIO, FIFO buffer.
Hm, not so simple as I thought it would be. So Cronus will more work as an orchestrator between the different components. In that case, the DAC has an excellent clock. Than the only improvement that is left will be to isolate the data lines. The WaveIO has an isolated output but this circuit is broken. Maybe I will only use the Hermes for that purpose but that is missing the U.fl connections I’d like to use.
Hermes is just an isolator. You might find the dac sounds worse going through Hermes, or it might sound better, or maybe no difference. Isolators do increase jitter, which reclocking would fix. But maybe the jitter won't be noticeable.
Sounds like it’s better to spare me all the effort. 🙄
Any experience with the difference in NZ2520SD and NZ2520SDA in relation to the WaveIO?
Any experience with the difference in NZ2520SD and NZ2520SDA in relation to the WaveIO?
Hey, happy to work though with you if you want. Just letting you know up front there is certain amount of details to get pretty much right if you want it work well.
The SDA version has lower phase noise, although it is not exactly specified over the range of interest for audio. A lot of dac performance and even clock performance depends on the quality of the circuitry around dacs and clocks, and how they are laid out. Its not just key parts one chooses. Its a lot of stuff that matters at RF frequencies and that eventually can impact audio.
Again, I want you to know that performance depends on a a lot of little technical details. I don't know the WaveIO boards well, so I can't speak in detail to them specifically. If you have schematics and gerbers, that type of thing, might be able to say more.
Thank you for your offer. I’ve spoken to someone on another forum a year ago who told me quite the same; its about the implementation.
I must say I’m a Sunday DIY-er and I thought to make a quick win with two boards which I’ve bought but have no use for at the moment. My thought was to make the chain a bit more perfect with an extra cleaning up of the data signal and set the timing absolutely right for the DAC. But as you told me the Cronus isn’t suitable for the way I had planned it could work and only isolate the data signal could introduce more jitter (who wants that) which requires to recklock the signal.
So maybe I’m at the end of what can be reached for me within this chain. It’s not that there are problems at the moment but you know, it could always be some more of the absolutely the right way to do it 🙂
For the WaveIO I don’t have any more information than the website offers.
Thanks for the help anyway!
I must say I’m a Sunday DIY-er and I thought to make a quick win with two boards which I’ve bought but have no use for at the moment. My thought was to make the chain a bit more perfect with an extra cleaning up of the data signal and set the timing absolutely right for the DAC. But as you told me the Cronus isn’t suitable for the way I had planned it could work and only isolate the data signal could introduce more jitter (who wants that) which requires to recklock the signal.
So maybe I’m at the end of what can be reached for me within this chain. It’s not that there are problems at the moment but you know, it could always be some more of the absolutely the right way to do it 🙂
For the WaveIO I don’t have any more information than the website offers.
Thanks for the help anyway!