LANRover - Receiving unit's 5Vdc Input


#1

Hi Paul @adminpaul

Just ordered a LANRover for my desktop setup - can’t wait to get it next week.

Regarding the receiving unit only, is the input 5Vdc power galvanically isolated from the USB output?

If it is, I’d rather not spend a fortune on the 5Vdc power supply

If the 5Vdc isn’t galvanically isolated from the USB output, I probably will have to buy the Uptone LPS-1

Appreciate if you can clarify

Cheers! laugh


#2

It is not unless your DAC disconnects it. You cannot galvanically isolate a voltage like that.

To be honest, I would start with the LANRover’s supply and get used to everything. It’s pretty good the way it is and that’s how I use it.


#3

Thanks Paul.

Just reading some comments by Alex of Uptone Audio over on CA: http://www.computeraudiophile.com/f8-general-forum/ps-audio-lanrover-28397/index6.html

Does the LANRover use switching voltage regulators or linear voltage regulators, regarding the 5V to 3.3V voltage regulation mentioned?

Just out of curiosity of course because these things interest me ! :slight_smile:


#4

I believe it’s a SMPS - it’s a cheap little DC supply, no doubt about it. And, the Uptone will sound better. My point it that the difference isn’t huge - not like the initial impact on sound quality the LANRover makes. Get used to it, find out all benefits and then, if you want to upgrade, go for it.


#5

Thanks Paul, I definitely will be getting used to it for a long time - there’s no room in my budget for a pricey external power supply for a while ! :slight_smile:

What power supply do you use with your LANRover if you don’t mind me asking?

Cheers !


#6

The stock one it comes with. I have tried others and frankly, find little difference - at least on DirectStream as fed from LANRover.


#7

Nice. Thanks Paul. Looking forward to sharing my experiences next week when the LANRover arrives.


#8
Paul McGowan said

The stock one it comes with. I have tried others and frankly, find little difference - at least on DirectStream as fed from LANRover.

Can you shed some light on the USB signal regenerating that the LANRover is doing.

I’m using the LANRover with a Chord Mojo for my desktop setup.

I know the marketing description talks about regeneration but is it the same type of USB signal regen, that the Uptone Audio REGEN is doing and done in a similar way?

Alex of Uptone mentions the USB signal integrity coming out of his ICRON (the isochronous model - different product I know) needs conditioning.

Wondering if the LANRover has this feature and does it in a similar way to the Uptone REGEN?

Cheers again


#9
Paul McGowan said

I believe it’s a SMPS - it’s a cheap little DC supply, no doubt about it. And, the Uptone will sound better. My point it that the difference isn’t huge - not like the initial impact on sound quality the LANRover makes. Get used to it, find out all benefits and then, if you want to upgrade, go for it.


Hi Paul. Are there plans for an upgrade to the LANRover this year, to use ultra low noise linear regulators? I’m certainly no expert but the microRendu’s and SOtM SMS-200’s and other USB source audio devices at the moment seem to really push this in their marketing, touting that switching regulators add detrimental noise.

I’m not asking in a cynical smarty pants way either - genuine query / request.

Cheers !


#10

Here’s the thing about SMPS. They are noisy. But not their output. The one we use provides clean, low noise DC power. The process they use to make that DC power is a noisy one - with EMI (radiated noise) from the switcher. Placing an SMPS inside the equipment is a major challenge for any designer and the source of many gray hairs. But placing it away from the product, as we do in this simple wall wart, removes that noise and any EMI that can get in.

If you take the output of the SMPS and look at it on the scope, you see no difference in cleanliness than that of a conventional supply with its linear regulators.


#11
Paul McGowan said

Here’s the thing about SMPS. They are noisy. But not their output. The one we use provides clean, low noise DC power. The process they use to make that DC power is a noisy one - with EMI (radiated noise) from the switcher. Placing an SMPS inside the equipment is a major challenge for any designer and the source of many gray hairs. But placing it away from the product, as we do in this simple wall wart, removes that noise and any EMI that can get in.

If you take the output of the SMPS and look at it on the scope, you see no difference in cleanliness than that of a conventional supply with its linear regulators.


Thanks Paul. If I understand correctly,you’re talking about the external 5Vdc SMPS (wall wart). But I was asking about the internal voltage regulators inside the LANRover RECEIVER unit - that provide the 5V to 3.3V voltage regulation.

You mentioned earlier it was a cheap switching voltage regulator that was inside the unit? Unless I misunderstood (wouldn’t be the first time for me !)

Cheers ! :slight_smile:


#12

Oh. No. Sorry. Inside is a nice linear regulator.


#13
Paul McGowan said

Oh. No. Sorry. Inside is a nice linear regulator.

I thought this had to be the case but you had me worried.

Alex might have hinted that his ICRON isochronous model has a noisy switching regulator inside.

I was thinking there was no way you could leave that in there for your custom built and custom designed product !

This wasn’t making a lot of sense but now it all makes plenty of sense lol

This would explain why the choice in wall wart or external PSU makes less difference too

Thanks Paul


#14

Yeah, all the noise is in the wall wart.


#15
Paul McGowan said

Yeah, all the noise is in the wall wart.


Can you shed some light on the USB signal integrity regenerating that the LANRover is doing.

I know the marketing description talks about regeneration but is it the same type of USB signal regen, that the Uptone Audio REGEN is doing and done in a similar way?

Alex of Uptone mentions the USB signal integrity coming out of his ICRON (the isochronous model – different product I know) needs conditioning.

Wondering if the LANRover has this feature built in

Cheers again

Paul McGowan said

Yeah, all the noise is in the wall wart.


#16

The LANRover and the Regen are trying to do two different things. You system may need one, the other or none. Comparing them directly on paper doesn’t get you far IMO.

Both “regenerate” the USB, and in fact the LANRover goes further along this path than the Regen since it converts the USB to Ethernet - whether this difference makes an audible difference depends on the system and the user’s preferences.

The Regen doesn’t directly address jitter or noise but instead tries to generate a signal that allows the ultimate USB receiver to not have to work as hard to interpret the USB signal - it needs to be very close to the ultimate USB receiving hardware to do this most effectively. That signal conditioning is not an explicit feature of the LANRover. On the other hand the galvanic isolation and jitter performance of the LANRover isn’t design feature of the Regen.

The LANRover is principally designed to allow a network as a USB to USB bridge and to take advantage of the isolation and allow a longer distance than a standard USB cable. There’s more buffering in a LANRover than the Regen and that may or may not help lower jitter.


#17
Ted Smith said

The LANRover and the Regen are trying to do two different things. You system may need one, the other or none. Comparing them directly on paper doesn’t get you far IMO.

Both “regenerate” the USB, and in fact the LANRover goes further along this path than the Regen since it converts the USB to Ethernet - whether this difference makes an audible difference depends on the system and the user’s preferences.

The Regen doesn’t directly address jitter or noise but instead tries to generate a signal that allows the ultimate USB receiver to not have to work as hard to interpret the USB signal - it needs to be very close to the ultimate USB receiving hardware to do this most effectively. That signal conditioning is not an explicit feature of the LANRover. On the other hand the galvanic isolation and jitter performance of the LANRover isn’t design feature of the Regen.

The LANRover is principally designed to allow a network as a USB to USB bridge and to take advantage of the isolation and allow a longer distance than a standard USB cable. There’s more buffering in a LANRover than the Regen and that may or may not help lower jitter.

Ted Smith said

The LANRover and the Regen are trying to do two different things. You system may need one, the other or none. Comparing them directly on paper doesn’t get you far IMO.

Both “regenerate” the USB, and in fact the LANRover goes further along this path than the Regen since it converts the USB to Ethernet - whether this difference makes an audible difference depends on the system and the user’s preferences.

The Regen doesn’t directly address jitter or noise but instead tries to generate a signal that allows the ultimate USB receiver to not have to work as hard to interpret the USB signal - it needs to be very close to the ultimate USB receiving hardware to do this most effectively. That signal conditioning is not an explicit feature of the LANRover. On the other hand the galvanic isolation and jitter performance of the LANRover isn’t design feature of the Regen.

The LANRover is principally designed to allow a network as a USB to USB bridge and to take advantage of the isolation and allow a longer distance than a standard USB cable. There’s more buffering in a LANRover than the Regen and that may or may not help lower jitter.


Thanks Ted! I certainly wasn’t comparing the products as a whole - I was only asking about the USB signal integrity feature of the Regen.

I completely understand all the other differences, including the ethernet transformer isolation of the LANRover for breaking groundloops and leakage current loops etc, which the Regen doesn’t address. Huge advantages of the LANRover but I wasn’t asking about that.

So when you say the Regen “tries to generate a signal that allows the ultimate USB receiver to not have to work as hard to interpret the USB signal” am I correct in saying that this is not something that the LANRover does?

This is the only feature I was asking about. As you say they’re not the same product types as a whole. The reason I ask, is Alex of Uptone says (in the forum linked above) he needs to use a Regen after his ICRON Isochronous - he says the ICRON doesn’t address USB signal integrity.

So I wanted to ask if the LANRover has this as a feature over the ICRON.

Thanks again!


#18

First off, I suspect that you will hear differences in your system between all four combinations of LANRover and Regen in and out of the circuit. The only way to tell if the differences you hear are to your taste and/or budget is to listen for yourself.

Perhaps my quibbles are just semantics, but I suspect that’s the nature of your question as well.

The LANRover regenerates the USB signal just as surely as the Regen - in fact it goes further from the original USB signal than the Regen.

The phase “… the ICRON doesn’t address USB signal integrity.” can be easily misunderstood. Usually when someone says that a signal doesn’t have good integrity that means that it is corrupt. Both the LANRover and the Regen generate valid USB signals and deliver those signals with good integrity. The Regen is attempting to generate as precise and repeatable USB waveforms as possible. The LANRover nominally has a longer path from it’s USB transceiver to the DACs transceiver, so the waveform is undoubtedly a little less precise, but both get the data there correctly.

Just because a device wasn’t built with a specific goal in mind doesn’t mean that it completely misses that goal.


#19

Thanks so much again Ted

I’m actually planning to use the LANRover with only a 2 foot Cat6a (floating shield) ethernet cable. Basically to get the ethernet galvanic (transformer) isolation from the PC USB.

I know most people won’t use it this way but the USB out from the LANRover Receiving unit will undoubtedly be better (noise and jitter) than the PC’s USB audio out for all the reasons you’ve mentioned.

Over such a short distance the USB signal integrity issue is probably insignificant compared with other issues, like EMI/RFI of the PC so close to the Dac


#20

Just on this Ted “so the waveform is undoubtedly a little less precise, but both get the data there correctly.”

If I have a USB source (not a high quality source like LANRover or Regen - say a cheap 5 meter long USB cable from a PC’s asynch USB output) that gets the data to the DSD Snr USB input correctly but with shockingly bad precision (very bad USB signal integrity), is it taken care of bythe DSD Snr FPGA anyway?