Sonore microRendu

[pageman99]

Too late to get on the mailing list?

 

Ok, Jesus, how do we get in the queue?

[pageman99]

Deleted.

[orgel]

Ok, Jesus, how do we get in the queue?

 

Everything is on order and we are waiting for the parts to arrive. I don't even have a unit at this point because my unit is out for initial feedback from industry friends. When we are ready an email will going to out to the people that participated in the microRendu mailing list. BTW I closed the mailing list when we sent out the first update a few weeks go.

 

I'm sure that when people on the mailing list start ordering their microRendu's, you will hear about it. IMO (and this is a case of do what I say, not what I do), it might be best to give Jesus a bit of a break so he can take care of business.

 

--David

[nyc_paramedic]

 

Don't give up on USB so fast. From my experience the microRendu can radically improve the performance of a DAC over its USB input, there is a fairly good probability that your DAC will sound as good or even better over USB with the microRendu. It may not do this in every case, but I have heard this happen on every DAC I have used it with (not very many at this point so it is not a guarantee, but it does seem to be trending that way).

 

John S.

 

John,

 

Is this true for USB DACs like the Ayre QB-9 that is opto-isolated from USB and runs Rankin's Streamlength Asychronous code and does not rely on the computers clocks?

 

Nick

[Superdad]

John,

 

Is this true for USB DACs like the Ayre QB-9 that is opto-isolated from USB and runs Rankin's Streamlength Asychronous code and does not rely on the computers clocks?

 

Nick

 

Hi Nick:

 

Virtually all USB DACs use async-USB inputs these days. Almost nobody sells a DAC with adaptive-USB anymore.

 

With regards the opto-isolators. All DACs that use digital isolators (be they RF type, opto-type, capacitive, or John's favorite magneto-resistive), place them AFTER the USB input PHY and processor (and generally reclock as they all add jitter). But by the time the signal becomes I2S headed towards the DAC chip, much of what happened at the input stage (ground plane noise, jitter, etc.) is somewhat baked-in. That's because those isolators isolate just the ground planes--the signal has to pass.

 

This is why the REGEN is effective even with all the "galvanically isolated" DACs--much to the chagrin of some of the designers. So yes, that applies to the Ayre QB-9 as well.

 

Hope that helps.

 

--Alex C.

[jabbr]

With regards the opto-isolators. All DACs that use digital isolators (be they RF type, opto-type, capacitive, or John's favorite magneto-resistive), place them AFTER the USB input PHY and processor (and generally reclock as they all add jitter). But by the time the signal becomes I2S headed towards the DAC chip, much of what happened at the input stage (ground plane noise, jitter, etc.) is somewhat baked-in. That's because those isolators isolate just the ground planes--the signal has to pass.

 

Alex,

 

With all due respect, this is just false. If it is possible that noise/jitter is actually baked into the USB signal, and if you are implying that jitter is additive, then why do the intermediate conversion from Ethernet -> USB -> I2S? You can't be suggesting that the USB step actually removes noise? Certainly not.

 

There is no such thing as "baked in" noise/jitter etc unless the bits themselves are altered. Likewise the "isolators" are free (and strongly encouraged) to use more sophisticated techniques than merely isolating the ground plane.

 

There are different strategies that DAC can use to "clean" an I2S/DSD signal, and it is pure utter hogwash to suggest that such cleaning is better applied at the USB stage.

 

For *example* LMK04821 | Dual / Cascaded PLL | Clock Jitter Cleaners | Description & parametrics there are techniques to "clean" a clock signal with femtosecond jitter results (have you measured your own circuitry this accurately?). Likewise there are common FPGA techniques to "clean" a datasignal e.g. the 1) isolation 2) FIFO and 3) reclock pathway, in that order***

 

Jonathan

 

***the reason this order (reclock last) is so important is that the reclock circuit in particular needs an extremely clean power supply if you are actually looking at 10s of femtosecond jitter levels. Thats where you go for the sub nV range noise.

[Superdad]

With all due respect, this is just false. If it is possible that noise/jitter is actually baked into the USB signal, and if you are implying that jitter is additive, then why do the intermediate conversion from Ethernet -> USB -> I2S? You can't be suggesting that the USB step actually removes noise? Certainly not.

 

There is no such thing as "baked in" noise/jitter etc unless the bits themselves are altered. Likewise the "isolators" are free (and strongly encouraged) to use more sophisticated techniques than merely isolating the ground plane.

 

There are different strategies that DAC can use to "clean" an I2S/DSD signal, and it is pure utter hogwash to suggest that such cleaning is better applied at the USB stage.

 

Hi Jonathan:

 

First off, I apologize to Jesus and all for going off topic. I did not even pay attention to which thread I was in when making the above post.

 

I am not the engineer here, nor do I pretend to be--and it is clear that I was inelegant enough in phrasing my comments to the extent that you misunderstood my points. So let's see if just stating a few non-controversial facts clears things up a little:

a) All digital isolators add jitter, typically a few hundred picoseconds worth;

b) All USB processing chips (be they programmed FPGA, XMOS, Cmedia, etc.) add a similar amount of jitter as well;

c) Reclocking flops are most often used after isolators to knock down some of that jitter.

 

So as to a perfect signal coming out of the isolators, that is not the case and it is not their job. (And my understanding of them pretty much stops there.)

 

But in no way was I suggesting that "cleaning of an I2S/DSD signal is better applied at the USB stage." My point was simply that isolators and reclocking after the USB stage do not completely immunize a DAC from what comes before. That's why people can still hear the difference between USB cables and why the REGEN works (making the DAC PHY's job easier such that it does not generate as much noise inside the DAC--noise that is pernicious enough to make it through isolation and to affect the DAC master clock).

 

Getting back to the microRendu:

To the extent that Ethernet's galvanic isolation keeps noise out of the device that is good. And while the Ethernet PHY does generate packet-noise, that is all before the entire iMX6 processor and John has done an outstanding job of separating power domains (you'll have to ask him how many there are in the microRendu), and moreover the clocking scheme and USB output sections of of the product are extraordinary (Jesus and John will reveal more about that in due time).

So I am not suggesting that the USB output is "cleaning" the I2S. Frankly I am not even sure if/where a distinct I2S signal is even generated in the microRendu as the USB sub-system is part of the processing module itself--which in turn feeds a hub chip for final REGEN-like signal-integrity/impedance match, again to help the DAC that follows it.

=========

 

And just to flesh out the above with words from the person I learn from, here is an excerpt from a post of John Swenson's in response to a question about why DACs with isolators (always after the USB input stage) still are audibly susceptible to upstream variables:

 

The isolation helps but is not nearly the panacea many people think. Lets travel through the system and look at both the power and signal and what happens to them as we go through the system.

 

So lets start with a USB receiver with bursts of high frequency noise on both the power and ground planes. This PG (power/ground) noise will modulate the data being sent to the isolators. It will slightly increase jitter and the amplitude of the pulses will vary with the noise.

 

This noisy power also goes into the driver side of the isolator. The signal going across the barrier (light, EM waves, magnetic field etc) gets modulated by this PG noise as well. The PG noise also changes the threshold of the input receivers, adding jitter to the signal.

 

On the other side of the barrier we have a couple things happening, the varying signal level, caused by the PG noise in the driver, also causes the receiver current to change, even with no signal applied. Thus the receiver causes PG noise on the "clean side" directly related to the PG noise on the "dirty side" It is definitely attenuated, but not by nearly as much as most people expect. Then we also have traditional logic noise caused by the fact the output is a normal logic signal, every time the output changes it creates noise on the PG planes on the clean side. The jitter on the signal created by the PG noise on the dirty side is still there PLUs jitter introduced by the isolation scheme. This jitter changes the spectrum of the logic noise on the PG planes on the clean side.

 

So then we feed the signal through a reclocking flop, which is supposed to get rid of all that jitter on the input. Well it helps, but no reclocking flops are completely effective. The PG noise at the flop still causes jitter to show up on it's output, PG noise changes the threshold where the flop detects the "switch" of the clock, thus increasing jitter on the output.

 

The result of this chain is that PG noise on the "dirty side" can still make it through to the "clean" side. It IS attenuated, but not completely gone.

 

Cascading such stages can theoretically help, but in order for that to work the reclocking clock has to get fed back through the isolators which significantly degrades the clock so it turns out cascading doesn't help much. (a two stage cascade does make things better, but not by a huge amount).

 

 

Again, very sorry for the off-topic.

 

--Alex C.

[Guidof]

Jesus,

 

I'm trying to understand what the microRendu does, but I'm thoroughly confused by the product description.

 

If the output of the microRendu is USB, then aren't the "selectable output modes" in the product description really (Ethernet} input modes?

 

Please help me understand how this product is intended to function. Thanks.

 

Best regards,

 

Guido F.

[sm31]

Don't think it's complicated; this may help: http://www.computeraudiophile.com/content/684-quick-spin-roonready-sonore-sonicorbiter-se/

[vortecjr]

Jesus,

 

I'm trying to understand what the microRendu does, but I'm thoroughly confused by the product description.

 

If the output of the microRendu is USB, then aren't the "selectable output modes" in the product description really (Ethernet} input modes?

 

Please help me understand how this product is intended to function. Thanks.

 

Best regards,

 

Guido F.

 

You could look at it that way. Just to clarify though...when you select an output mode the remaining output modes are not doing anything. All you need in the audio room is the microRendu connected to power, network, and your audio system. All you need to stream to it is a NAS or computer running LMS on the network. Most any NAS or computer will do. In this example, I assume that you have selected SqueezeLite output mode. With the microRendu you no longer need a complex music server in the audio room wiping away unwanted hardware and software. Whats left is roughly the size of a credit card (LxW) streaming USB Audio to your gear. You also needed an external power supply, but if you already have a good one that is great because we will offer the microRendu without it as an option.

[jabbr]

Hi Jonathan:

 

First off, I apologize to Jesus and all for going off topic. I did not even pay attention to which thread I was in when making the above post. ...

I've responded here so that we don't tread on this thread My apologies also

[vortecjr]

No problem. I'll be following along on the new thread from the sidelines.

[sbank]

Jesus,

 

Does this quote from you in the SonicOrbiter SE thread also apply to the microRendu?

 

"2. Sonicorbiter now have the ability to add a custom USBhardware address for certain devices that need to be initialed in ALSA with a none standard hardware address. FYI Most devices will not need this feature. However, one such device that needs this feature is a Schitt Gungnir DAC that is based on a C-MediaUSB receiver chip. The Schitt Gungnir DAC works best when setup to hardware address hw:1,1."

 

Also does this apply to both the orginal version of the Gungnir and the newer Gungnir Multibit? Thanks much.

[vortecjr]

Jesus,

 

Does this quote from you in the SonicOrbiter SE thread also apply to the microRendu?

 

"2. Sonicorbiter now have the ability to add a custom USBhardware address for certain devices that need to be initialed in ALSA with a none standard hardware address. FYI Most devices will not need this feature. However, one such device that needs this feature is a Schitt Gungnir DAC that is based on a C-MediaUSB receiver chip. The Schitt Gungnir DAC works best when setup to hardware address hw:1,1."

 

Also does this apply to both the orginal version of the Gungnir and the newer Gungnir Multibit? Thanks much.

 

Yes. This will be included in the microRendu. It's likely that any Schitt DAC that uses the C-Media USB receiver chip will need this, but I'm not 100% sure because it's based on how they set things up in their firmware.

[Guidof]

You could look at it that way. Just to clarify though...when you select an output mode the remaining output modes are not doing anything. All you need in the audio room is the microRendu connected to power, network, and your audio system. All you need to stream to it is a NAS or computer running LMS on the network. Most any NAS or computer will do. In this example, I assume that you have selected SqueezeLite output mode. With the microRendu you no longer need a complex music server in the audio room wiping away unwanted hardware and software. Whats left is roughly the size of a credit card (LxW) streaming USB Audio to your gear. You also needed an external power supply, but if you already have a good one that is great because we will offer the microRendu without it as an option.

 

Thank you for the explanation, Jesus. So, if I understand you correctly, the "output" that is selectable is the server's output, not the microRendu's. Correct?

 

Thanks again for the prompt reply.

 

Guido F.

[Doak]

You could look at it that way. Just to clarify though...when you select an output mode the remaining output modes are not doing anything. All you need in the audio room is the microRendu connected to power, network, and your audio system. All you need to stream to it is a NAS or computer running LMS on the network. Most any NAS or computer will do. In this example, I assume that you have selected SqueezeLite output mode. With the microRendu you no longer need a complex music server in the audio room wiping away unwanted hardware and software. Whats left is roughly the size of a credit card (LxW) streaming USB Audio to your gear. You also needed an external power supply, but if you already have a good one that is great because we will offer the microRendu without it as an option.

 

So, according to the above I cannot connect the microRendu to my router then plug a USB HD music library plus my DAC into the microRendu and play music?

This is basically my current config using an Auralic Aries - except the connection to the router is via WiFi.

TIA

Doak

[hifial]

So, according to the above I cannot connect the microRendu to my router then plug a USB HD music library plus my DAC into the microRendu and play music?

This is basically my current config using an Auralic Aries - except the connection to the router is via WiFi.

TIA

Doak

 

If I am not mistaken. The microRendu has just ONE input, Ethernet and ONE output, USB. The USB is to connect directly to your DAC's USB input.

To use an USB HD you can use it in one of several ways.

Connect the USB HD to one of the unused USB ports on your computer that you then connect to your Router by Ethernet and that the microRendu is also connected to Router by Ethernet. Connect microRendu to your DAC by USB.

Use an NAS that also has USB ports and connect the NAS by Ethernet to the Router and do the same with the microRendu by Ethernet.Then connect your DAC to the microRendu by USB.

Maybe (Jesus will need to confirm): Use a Router that also has USB ports and connect the USB HD to it and then connect the microRendu to the Router by Ethernet.Connect your DAC to the microRendu by USB.

 

I believe the first two should work and maybe the third but Jesus will need to confirm all three.

[vortecjr]

Thank you for the explanation, Jesus. So, if I understand you correctly, the "output" that is selectable is the server's output, not the microRendu's. Correct?

 

Thanks again for the prompt reply.

 

Guido F.

 

No. What we call the "output mode" is in reference to what applications run on the microRendu. All the output modes on the microRendu are ported to stream via the USB port. On the Sonicorbter SE the output modes can be ported to stream to the units optical output or USB port selectable by the user via the GUI.

[vortecjr]

So, according to the above I cannot connect the microRendu to my router then plug a USB HD music library plus my DAC into the microRendu and play music?

This is basically my current config using an Auralic Aries - except the connection to the router is via WiFi.

TIA

Doak

 

This is specifically what we are trying to avoid with this product by design.

[vortecjr]

If I am not mistaken. The microRendu has just ONE input, Ethernet and ONE output, USB. The USB is to connect directly to your DAC's USB input.

To use an USB HD you can use it in one of several ways.

Connect the USB HD to one of the unused USB ports on your computer that you then connect to your Router by Ethernet and that the microRendu is also connected to Router by Ethernet. Connect microRendu to your DAC by USB.

Use an NAS that also has USB ports and connect the NAS by Ethernet to the Router and do the same with the microRendu by Ethernet.Then connect your DAC to the microRendu by USB.

Maybe (Jesus will need to confirm): Use a Router that also has USB ports and connect the USB HD to it and then connect the microRendu to the Router by Ethernet.Connect your DAC to the microRendu by USB.

 

I believe the first two should work and maybe the third but Jesus will need to confirm all three.

 

You can connect your drives anyplace on your network that your server software can access them.

[Iving]

Is it possible to enjoy a simple set-up comprising computer (maybe a PC, maybe a tablet) with or without external SSD (containing flacs), linked via network/ethernet to router, thence via network/ethernet to microRendu (thence via USB to DAC or pre-DAC digital converter such as Gustard U12):

1. using foobar as player at computer; i.e., without any need for HQPlayer or Roon or anything else like that for playing/streaming - I have no interest in any bells and whistles such as artwork or online shops/catalogues - only optimal SQ playing my personalised flacs (mostly just ordinary CD rips but stringent in Exact Audio Copy)?

2. seeing any necessary microRendu UIs at my PC without ancillary software?

3. with or without connecting to the internet; i.e., if I want to use the requisite router merely as a music signal relay and have no need for online data? (I have read someone suggesting that initial set-up of the microRendu requires engagement with a Sonore server but that the microRendu is fully functional as Hi-Fi offline after that?)

 

I am not an advanced audiophile in the digital domain and TIA for any helpful responses ...

[Doak]

This is specifically what we are trying to avoid with this product by design.

Gotcha.

It may be time to get serious about NAS.

[ted_b]

Gotcha.

It may be time to get serious about NAS.

 

A NAS is important, but mainly for large storage fault-tolerant easy access capability. If all you want to do is have the microRendu find your music, then hang the music off any computer in your network and throw the free Minimserver app on that computer, pointing it to your music. The microRendu will find it and play it.

[Dimitris71]

When will the microrendu come out in Europe? Thank you Dimitris

[Doak]

A NAS is important, but mainly for large storage fault-tolerant easy access capability. If all you want to do is have the microRendu find your music, then hang the music off any computer in your network and throw the free Minimserver app on that computer, pointing it to your music. The microRendu will find it and play it.

Thanks for the pointer Ted.