Auralic Aries & Sonore microRendu listening impressions

[davide256]

Just did round 2 of Aries Femto vs. uRendu. The changes relative to last time:

 

1. Aries firmware updated to 4.0.0, which defaults to RAM playback of files streaming from NAS.

 

2. uRendu configured in NAA mode. Control PC running HQPlayer & Windows Server 2012 R2 OS is based on a Gigabyte GA-H170TN thin mini-ITX motherboard with i7-6700T 35W CPU & 16GB of DDR3L memory and a Samsung 850 EVO 1TB M.2 SSD acting as both OS & music disk. A Netgear GS108v2 gigabit Ethernet switch connected this PC to the uRendu and the home network. LAN cable between uRendu and Control PC was a 1m CAT7 STP. uRendu USB output was run through an Intona USB isolator (industrial model) using a short USB A-to-B adapter. uRendu was powered with another modified Teradak 8.5V 1A LPSU adjusted to 6.25V output.

.....

I have very high regard for uRendu, as it is very good out-of-the-box, and was hoping I could get it to match or exceed the Aries Femto in SQ. I don't contest others hearing better sound from their uRendu vs. the Aries, as this is distinctly possible given different HW setups. Being a newer product the uRendu has perhaps a greater prospect of achieving tangible improvements in synergy and thus SQ with a variety of setups.

I suspect that without using optical Ethernet you have not heard either device to its full potential. Hopefully the difference widens.

[scan80269]

OK. Round 3 of Aries Femto vs. microRendu is in the bag.

 

This time it ended up being less of a direct shootout than an experimental tweak session for the Aries Femto.

 

microRendu setup:

 

* Power: UpTone UltraCap LPS-1, fed by included Mean Well 7.5V 2.9A SMPS

 

* Ethernet: HDPlex H1.S thin mini-ITX fanless silent PC (running WS2012R2 & HQPlayer, music library on M.2 SSD) <> 3' BJC CAT6a cable <> Netgear FS105 switch <> 3' BJC CAT6a cable <> EN-70HD isolator <> 1' BJC CAT6 cable <> microRendu (NAA mode)

 

* USB: microRendu <> VBus2 isolator <> 2' Supra USB cable <> Vega DAC

 

Overall sound was vastly improved over last time, and became very similar to Aries Femto streaming over dedicated 5GHz wireless. Gone were the lower perceived level of dynamics, lesser sound stage depth and shorter & weaker reverb tails heard previously (vs. Aries). This time the microRendu sounded beautifully, being much more alive and engaging. This may be the first time we heard the microRendu at or near its full potential.

 

I did uninstall Roon, SqueezeLite and Drive Mounter apps from the microRendu prior to this session.

 

My friend and I then went on to experimenting with Aries Femto. The following is listed in increasing SQ order:

 

0. Baseline: Aries in wireless mode, using dedicated 5GHz band of wireless router

 

1. Aries changed to wired mode, ~50' CAT5e cable (crimped by my friend) to TPLink AC3200 router in AP mode

 

2. EMO Systems EN-70HD isolator added going into Aries with 1' BJC CAT6a cable

 

3. Netgear FS105 Fast Ethernet switch added with 3' BJC CAT6a cable (between EN-70HD and router)

 

4. Removed 50' CAT5e cable, connected to D-Link 802.11n wireless bridge (actually router in bridge mode):

 

Final setup evaluated: NUC-based NAS (Win10, MinimServer/MinimStreamer, music library) <> CAT5e cable <> TPLink router <wireless> D-Link wireless bridge <> 1' BJC CAT6a cable <> Netgear FS105 switch <> 30' BJC CAT6a cable <> EN-70HD isolator <> 1' BJC CAT6a cable <> Aries Femto

 

Despite the higher complexity, this last setup yielded the best sound with Aries Femto we have ever heard at this venue! The improvement over the wireless baseline was substantial: stronger & tighter bass, deeper & rock solid soundstage, longer reverbs, more micro details, better tonal balance and improved integration of direct and hall sounds.

 

From 0 to 1 there was a sonic character change, but it was a bit hard to judge whether wireless or wired was the better sounding. The biggest SQ jumps were from 1 to 2 and from 2 to 3. The EN-70HD made a very noticeable improvement, same with the FS105 forcing Aries down to 100Mbps on Ethernet. 4 resulted in another small improvement, but was done mainly to get rid of that long 50' Ethernet cable running across the living room that I'm sure my friend's wife would never approve as permanent setup!

 

I wanted to power the FS105 switch with the LPS-1 but did not have a DC power cable with the right plug for the FS105, so the FS105 was powered by the included Netgear wall wart, plugged through a LC filter box.

 

We also compared the EMO Systems EN-70HD isolator with the Baaske MI-1005, swapping back and forth between the two. The EN-70HD slightly edged the MI-1005 in SQ, and both were superior to having no isolator.

 

We even tried a Sbooster BOTW 15V LPS replacing the Auralic LPS for Aries, but the sound immediately became less punchy and the bass oomph lessened noticeably. We could not explain this, other than perhaps the Sbooster wasn't at its best due to lack of break-in time, but we quickly went back to the Auralic LPS to restore the sound.

 

The Sbooster LPS was not outfitted with the Ultra, as Ciamara shipped me the wrong Ultra model and the replacement ordered separately has not arrived.

 

Thus some findings today:

 

* Ethernet isolators (like EN-70HD) can improve SQ!

 

* Ethernet at 100Mbps can deliver better sound than at gigabit

Observed with both microRendu and Aries Femto

 

* Uptone UltraCap LPS-1 works great with microRendu!

 

* microRendu with appropriate isolation measures sounds fantastic!

 

* Aries Femto in wired mode with Ethernet isolation can outperform wireless mode

Wireless can still be part of the audio streaming network, but Aries delivers better SQ receiving from Ethernet

 

One gratifying part of this hobby is in hearing tangible sonic improvements from a system with just tweaks as opposed to a major or complete overhaul. The Aries Femto / Vega DAC combo continues to impress us. We were all smiles at the end of this session.

 

My friend will be acquiring an EN-70HD isolator, some BJC CAT6a cables and a Fast Ethernet switch. I will be acquiring a router (as wireless bridge) to run Ethernet into my Aries downstairs.

 

I did not describe the rest of my friend's excellent system (amps, speakers, power conditioner, isolation transfomers, etc.) but can do so if anyone is interested.

[austinpop]

@scan80269

 

I want to be the first to thank you for your write up. Clearly, you did a very careful assessment, although it sounds you had fun doing it - as it should be!

 

A few observations:

 

a. You don't talk about USB tweaks, like Intona or Regen/RUR. I assume you didn't have any on hand to try? The reason I bring this up is that in my experiments with the Aries Mini (a close relative of your Aries Femto), I found the effect of network isolation was less noticeable in the presence of USB isolation. I would have been curious if you had seen the same.

b. Since you don't mention fiber or optical isolation on the network, I assume you didn't try this approach? Again, just curious how the fiber approach compares to the Emo/Baaske idolaters. In my setup, I felt the fiber outperformed.

 

Finally, with all tweaks at your disposal in place for both, would you say Aries Femto and mRendu were neck and neck?

[scan80269]

@scan80269

 

I want to be the first to thank you for your write up. Clearly, you did a very careful assessment, although it sounds you had fun doing it - as it should be!

 

A few observations:

 

a. You don't talk about USB tweaks, like Intona or Regen/RUR. I assume you didn't have any on hand to try? The reason I bring this up is that in my experiments with the Aries Mini (a close relative of your Aries Femto), I found the effect of network isolation was less noticeable in the presence of USB isolation. I would have been curious if you had seen the same.

b. Since you don't mention fiber or optical isolation on the network, I assume you didn't try this approach? Again, just curious how the fiber approach compares to the Emo/Baaske idolaters. In my setup, I felt the fiber outperformed.

 

Finally, with all tweaks at your disposal in place for both, would you say Aries Femto and mRendu were neck and neck?

@austinpop

 

I actually did bring an Intona and a W4S RUR, but didn't end up using either. In a previous session, an Intona inserted between Aries Femto and Vega DAC yielded no discernible SQ change, so we concluded the Intona does not benefit the Aries/Vega combo. I suppose I should have tried adding both Intona and RUR this time around, with a second LPS-1 powering the RUR, but the setup got rather complicated as it was, and we ran out of time for more experiments.

 

I have a pair of TrendNet and a pair of TPLink FMCs, but didn't bring them this time. The box of stuff got pretty heavy with my H1.S fanless server and Sbooster BOTW in it, and I barely got it hauled to my friend's place. I do agree a comparison between Ethernet isolator and FMCs would be meaningful, so hopefully one of these days. I may run out of LPS-1 units to power things like the downstream FMC though.

 

With this session, the mRendu did a fantastic job essentially equaling (or perhaps slightly exceeding) the Aries Femto in wireless mode. Changing the Aries Femto to wired mode and adding tweaks like Ethernet isolator and forcing 100Mbps Ethernet speed brought this renderer to a level of SQ that was totally unexpected. Wireless mode has been delivering SQ well beyond good for a long time, but wired mode as set up with this session was really something else. I now understand why davide256 suggested trying Ethernet for Aries.

 

I mentioned last time that I think the mRendu may be disadvantaged architecturally vs. the Aries Femto/LE/Mini with their 4.0.0 firmware having implemented memory playback. The Aries SQ step-up with memory playback was enormous as reported for the previous session. In contrast, the mRendu in NAA mode receives a continuous network stream from the HQPlayer PC. Even if HQPlayer can buffer part or all of a post-processed track in a PC with lots of RAM installed, I suspect that is not the right place for the buffering, as it won't help quiet down the network traffic streaming into the NAA. IIRC the mRendu doesn't have as much onboard RAM as Aries. so it may be more difficult to implement memory playback in the same way as Aries does, and track buffering may not make sense for NAA either (it may have no concept of track boundaries).

[austinpop]

@austinpop

 

I actually did bring an Intona and a W4S RUR, but didn't end up using either. In a previous session, an Intona inserted between Aries Femto and Vega DAC yielded no discernible SQ change, so we concluded the Intona does not benefit the Aries/Vega combo. I suppose I should have tried adding both Intona and RUR this time around, with a second LPS-1 powering the RUR, but the setup got rather complicated as it was, and we ran out of time for more experiments.

 

FWIW - I found the combo of Intona AND RUR (powered by an el cheapo Breeze LPS) to be quite a noticeable improvement with my Aries Mini, and this is even before an LPS-1 - still waiting on mine! If you already have these, you owe it to yourself to give this a whirl - perhaps borrowing the second LPS-1 from the mRendu for the experiment.

 

I have a pair of TrendNet and a pair of TPLink FMCs, but didn't bring them this time. The box of stuff got pretty heavy with my H1.S fanless server and Sbooster BOTW in it, and I barely got it hauled to my friend's place. I do agree a comparison between Ethernet isolator and FMCs would be meaningful, so hopefully one of these days. I may run out of LPS-1 units to power things like the downstream FMC though.

 

Completely understand. Again, I found the FMC's to sound better than the Baaske, but I'm curious if that gets reversed with the Emo or the Etalon. BTW - I haven't heard of anyone comparing the downstream FMC with LPS-1 and some other LPS or battery. I'm still playing with the PSU for this. I started with SMPS, went to Jameco 9V, then Tecknet 5V, charged with Jameco 5V. I'm now trying the Teralink X1/X2 U9VA LPS with it, and it is sounding rather good. However the PSU differences are very small to my ears, so I really wonder if an LPS-1 isn't overkill for this application anyway.

 

Changing the Aries Femto to wired mode and adding tweaks like Ethernet isolator and forcing 100Mbps Ethernet speed brought this renderer to a level of SQ that was totally unexpected. Wireless mode has been delivering SQ well beyond good for a long time, but wired mode as set up with this session was really something else. I now understand why davide256 suggested trying Ethernet for Aries.

 

This has been my experience too - and I've been recommending this over on the Overall Isolation thread. I have tried going back to wireless several times, and can reliably hear the improvement with wired, which the isolation (FMCs in my case) only extends further.

[MrUnderhill]

Thx Scan,

 

Enjoying your thread, and looking forward to the next installment.

 

M

[wanta911]

Thanks for your detailing your experiences so far - very interesting!

 

* Ethernet at 100Mbps can deliver better sound than at gigabit

Observed with both microRendu and Aries Femto

 

I'm curious about this particular aspect of 100Mbps vs gigabit, what would be the reason for this?

[scan80269]

I'm curious about this particular aspect of 100Mbps vs gigabit, what would be the reason for this?

My take on this is that at 100Mbps the Ethernet receiver (PHY) on the Aries has to work less hard (and generate less electrical noise) than at gigabit speed to retrieve the digital bitstream. 100Mbps (100BASE-TX) operates with only two wire pairs and at one bit per symbol vs. gigabit (1000BASE-T) operating with all four wire pairs and at two bits per symbol. In my experience, better SQ results when the electrical noise level on the Aries circuit board(s) can be reduced, for example by lowering processor workload, using 100Mbps wired instead of wireless, no USB storage attached and so on.

[R1200CL]

Would be very interesting to hear if any difference between FMC and Intona.

You should/could use a Y-split cable from the LPS-1 in order to power both the MicroRendu and FMC.

(Unless you have a second LPS-1, or maybe only like to use the Aries)

 

If you happen to have 2 LPS-1, how about test with those in series and verify if the Aries can be powered with that configuration ?

(IIRC Aries use 12 V, and between 1 and 1,2 A).

 

 

Sent from my iPad using Computer Audiophile

[Hauser]

I too would be very interested to know the results of this experiment. Currently considering the purchase of Vinnie Rossi's Mini cap power supply, an all in one box with 2.5A current at same price as 2 LPS-1s.

 

Martin.

[scan80269]

I do have two LPS-1, but won't attempt to wire them in series to power my Aries Femto. One LPS-1 is dedicated to my microRendu. The Vinnie Rossi Mini PS at 12V is much more suited to powering the Aries Femto, and I'm tempted to invest in one myself.

 

One experiment I may do next is to insert a pair of TrendNet FMCs and fiber optic cable between the Aries Femto and Netgear FS105v3 switch, to compare with the EMO Systems EN-70HD Ethernet isolator. I can power the downstream FMC with an LPS-1 for the ultimate isolation.

[asdf1000]

Hi, great thread.

 

Just an open question for all: Since the microRendu's ethernet input is already galvanically isolated, what may be the technical reasons or causes for further sound quality improvements when adding even more ethernet isolation?

 

Many thanks in advance

[r_w]

scan80269

 

Good thread, I salute your work.

 

... as an aside, have you compared the Aries/Vega combo with USB vs AES-EBU?

[scan80269]

Hi, great thread.

 

Just an open question for all: Since the microRendu's ethernet input is already galvanically isolated, what may be the technical reasons or causes for further sound quality improvements when adding even more ethernet isolation?

 

Many thanks in advance

In theory, Ethernet is always galvanically isolated by its use of pulse transformers, so no additional isolation is needed. However, galvanic isolation means DC currents getting blocked. AC currents at a certain frequency range can still jump through the pulse transformer due to capacitive coupling between transformer primary and secondary windings. Also, common-mode noise rejection at the receiver on each end may be good but not perfect, and waveform distortion by the cable is a reality depending on the quality of the cable (e.g. consistency of differential impedance, susceptibility to external interferences, etc.). Anything that causes the differential signal waveform as seen by the receiver to deviate from the ideal will cause the receiver to work harder to retrieve the digital bitstream, create more electrical noise and thus impact the SQ.

 

My friend and I distinctly heard the SQ improve when an EN-70HD isolator was inserted just before the Aries Femto. I also believe the SQ can vary by the Ethernet cables used, though we have not done any listening tests to investigate. These days I'm a fan of BlueJeansCable CAT6a UTP cables as they use cable stock with bonded pairs for impedance consistency and ship every cable ordered with a test report. I don't use CAT7 since the shielded cables defeat galvanic isolation. I don't use cheap Ethernet cables from local store either. These may be good enough for general purpose networking use but are often not optimal for digital audio transportation.

 

My digital audio experiences in the past few years have made me a believer of:

 

"In theory there is no difference between theory and practice. In practice there is."

[R1200CL]

One experiment I may do next is to insert a pair of TrendNet FMCs and fiber optic cable between the Aries Femto and Netgear FS105v3 switch, to compare with the EMO Systems EN-70HD Ethernet isolator. I can power the downstream FMC with an LPS-1 for the ultimate isolation.

 

Did you test EN-70HD with MicroRendu ?

Also I suppose you will do the FMC test vs EN-70HD with MicroRendu in addition to with Aries?

I think the only option is to power the FMC by a Y-split from LPS-1 [emoji3]

[scan80269]

scan80269

 

Good thread, I salute your work.

 

... as an aside, have you compared the Aries/Vega combo with USB vs AES-EBU?

My friend has spent considerable time comparing USB with AES-EBU for the Aries/Vega combo. For many months he has preferred AES-EBU, but things changed after one tweak: adding a Jensen balanced transformer to the Vega balanced analog outputs. USB used to sound brighter along with a bit more treble harshness vs. AES-EBU but not after the Jensen transformer was added. One hypothesis is that Vega analog outputs have a bit of ultrasonic frequency left in it due to use of gentle low-pass filtering after the D-to-A conversion at 1.5MHz. The ultrasonic content may be affecting the Benchmark AHB2 amps that apparently have wide bandwidth inputs.

 

As to why USB would benefit more than AES-EBU with transformer insertion on the analog side of the DAC, I can only guess it has something to do with a leakage current loop getting broken by the transformers. By the way, my friend heard a small but definite SQ improvement when an SBooster VBus2 isolator was added to the USB cable between Aries and Vega. What appears to be counterintuitive is that adding certain pieces of equipment to the system can improve the SQ, often contradicting "less is better". There are more and more devices within my friend's system (Fast Ethernet switch being one of the latest additions), but the sound has been steadily improving...

 

As if this is not confusing enough, we tried adding an Intona USB isolator between Aries and Vega but there was no discernible SQ difference. One would think that if USB was somehow involved in a leakage loop that isolation by Intona would help but it didn't. The SQ didn't get worse with Intona but there was no improvement either.

 

Experimentation is what my friend and I enjoy doing with our digital audio systems. Every time we started thinking the SQ cannot possibly get much better, along comes a tweak delivering astonishing results.

[scan80269]

Did you test EN-70HD with MicroRendu ?

Also I suppose you will do the FMC test vs EN-70HD with MicroRendu in addition to with Aries?

I think the only option is to power the FMC by a Y-split from LPS-1 [emoji3]

 

In the previous listening session the EN-70HD was part of the microRendu setup, though we didn't evaluate removing the EN-70HD.

 

I can look into the EN-70HD vs. FMC comparison with the microRendu. The Aries setup is easier to experiment with as I don't have to bring my silent PC to run HQPlayer which is required for microRendu in NAA mode. I can't make any promise for this evaluation, as my friend is more interested in tweaks for Aries being part of his current setup. The microRendu has not bested the Aries Femto in three sessions, so I have to convince my friend to go for another round with microRendu. To be fair, Aries and microRendu should stream from the same music source, but the silent NUC I built for my friend running MinimServer and carrying his music library for the Aries may not be powerful enough to run HQPlayer, unless upsampling is disabled or set to integer multiple with a light algorithm. Music source is therefore one aspect that has not been equalized between Aries and microRendu. I may want to try this anyway just to experience how the SQ changes. I can also change the microRendu to DLNA mode and run Kazoo on the iPad. Comparing SQ between DLNA and NAA modes of microRendu is yet another experiment.

 

I do have two LPS-1 so can use one for microRendu and another for the downstream FMC.

[austinpop]

In the previous listening session the EN-70HD was part of the microRendu setup, though we didn't evaluate removing the EN-70HD.

 

I can look into the EN-70HD vs. FMC comparison with the microRendu. The Aries setup is easier to experiment with as I don't have to bring my silent PC to run HQPlayer which is required for microRendu in NAA mode. I can't make any promise for this evaluation, as my friend is more interested in tweaks for Aries being part of his current setup. The microRendu has not bested the Aries Femto in three sessions, so I have to convince my friend to go for another round with microRendu. To be fair, Aries and microRendu should stream from the same music source, but the silent NUC I built for my friend running MinimServer and carrying his music library for the Aries may not be powerful enough to run HQPlayer, unless upsampling is disabled or set to integer multiple with a light algorithm. Music source is therefore one aspect that has not been equalized between Aries and microRendu. I may want to try this anyway just to experience how the SQ changes. I can also change the microRendu to DLNA mode and run Kazoo on the iPad. Comparing SQ between DLNA and NAA modes of microRendu is yet another experiment.

 

I do have two LPS-1 so can use one for microRendu and another for the downstream FMC.

 

Scan:

 

Why involve HQPlayer at all? Why don't you just run mRendu in MPD/DLNA mode, pulling from the same MinimServer? That would also isolate the comparison to exactly one variable - Aries vs mRendu.

[scan80269]

Scan:

 

Why involve HQPlayer at all? Why don't you just run mRendu in MPD/DLNA mode, pulling from the same MinimServer? That would also isolate the comparison to exactly one variable - Aries vs mRendu.

The first listening session described in post #1 was with the microRendu in MPD/DLNA mode, since back in July I was not an HQPlayer user. So it was actually a more fair comparison, with both Aries and microRendu playing from the same NUC/MinimServer source. The SQ difference between Aries & microRendu was by far the largest with that first session though. I also did not have the LPS-1 back then (for obvious reason) or the EN-70HD isolator or FMCs or BJC CAT6a cables.

 

I suppose another session between Aries & microRendu (in DLNA mode) with 100Mbps Ethernet streaming and all the isolation tweaks is called for.

[R1200CL]

Scan:

 

Why involve HQPlayer at all? Why don't you just run mRendu in MPD/DLNA mode, pulling from the same MinimServer? That would also isolate the comparison to exactly one variable - Aries vs mRendu.

 

Then I would add, better do Roon, as both Aries and MicroRendu support RAAT. [emoji3]

 

You don't need a separate device for Roon, although it is suggested that is the best setup

http://www.audiostream.com/content/intel-nuc-sonictransporter-tale-two-mini-computers-running-roon-core#to9f9bxAZtq4iYsQ.97

[austinpop]

Then I would add, better do Roon, as both Aries and MicroRendu support RAAT. [emoji3]

 

Yeah fair enough. Either way, my point was not to vary two variables at once. Hold the music source - whether DLNA, Roon, or Roon/HQPlayer - constant, and only vary Aries or mRendu.

[austinpop]

 

I suppose another session between Aries & microRendu (in DLNA mode) with 100Mbps Ethernet streaming and all the isolation tweaks is called for.

 

That would indeed be very interesting!

[asdf1000]

In theory, Ethernet is always galvanically isolated by its use of pulse transformers, so no additional isolation is needed. However, galvanic isolation means DC currents getting blocked. AC currents at a certain frequency range can still jump through the pulse transformer due to capacitive coupling between transformer primary and secondary windings. Also, common-mode noise rejection at the receiver on each end may be good but not perfect, and waveform distortion by the cable is a reality depending on the quality of the cable (e.g. consistency of differential impedance, susceptibility to external interferences, etc.). Anything that causes the differential signal waveform as seen by the receiver to deviate from the ideal will cause the receiver to work harder to retrieve the digital bitstream, create more electrical noise and thus impact the SQ.

 

My friend and I distinctly heard the SQ improve when an EN-70HD isolator was inserted just before the Aries Femto. I also believe the SQ can vary by the Ethernet cables used, though we have not done any listening tests to investigate. These days I'm a fan of BlueJeansCable CAT6a UTP cables as they use cable stock with bonded pairs for impedance consistency and ship every cable ordered with a test report. I don't use CAT7 since the shielded cables defeat galvanic isolation. I don't use cheap Ethernet cables from local store either. These may be good enough for general purpose networking use but are often not optimal for digital audio transportation.

 

My digital audio experiences in the past few years have made me a believer of:

 

"In theory there is no difference between theory and practice. In practice there is."

Thank you! Does the point about AC currents jumping through the pulse transformers still apply to ethernet cables that have a floating shield design? Or am I confusing two totally different issues? Many thanks again

 

 

Sent from my Blackberry DTEK50 using Tapatalk

[Superdad]

Wow, cool thread! I'm late to this party.

(Been too busy building more LPS-1 units to keep you gents satisfied Have not had time to look for new threads to subscribe to.)

 

I might finally try one of those EMO EN-70HD isolators on my BJC/Belden CAT6A now that there seems to be consensus that it is the best of them.

 

Best,

--Alex C.

[scan80269]

Thank you! Does the point about AC currents jumping through the pulse transformers still apply to ethernet cables that have a floating shield design? Or am I confusing two totally different issues? Many thanks again

 

Any AC noise jumping through the Ethernet pulse transformer would get carried by the twisted pairs of the cable to the other end. I believe this can occur even with cables that have a floating shield or no shield. CAT5e and CAT6 cables are typically U/UTP (i.e. no outer shield & no individual twisted pair shields, just 4 twisted pairs). The noise can run over the twisted pairs. The differential receiver in the Ethernet PHY is designed to achieve common-mode noise rejection, but any noise not coupling equally to the two wires of a differential pair will not get perfect attenuation. Common mode noise will still be normally reduced by quite a lot of dB by the differential receiver, but it may not be completely eliminated. These hypotheses are based on listening observations showing the EN-70HD isolator can improve SQ when all the Ethernet cables involved are of the unshielded type.

 

I suspect the Ethernet isolators offer an additional amount of AC noise reduction. Putting an EN-70HD just before the Aries can help attenuate noise picked up by the Ethernet cable run that is not optimally cancelled by common-mode rejection. I would guess the lower the cable quality (in terms of upholding signal integrity) the more effective an Ethernet isolator may be.

 

One thing I'll likely do in copying my friend is to use a wireless bridge to connect my Aries (downstairs) to the NAS (upstairs) thereby changing Aries from wireless to wired and eliminating the need for a long Ethernet cable run between the Aries and my wireless router (which I'm sure my wife would object to). I'm seriously considering replacing my Netgear R8500 router with a Netgear Orbi router/satellite pair. The Orbi router would sit upstairs next to my NAS, and the satellite (in wireless bridge role) would sit near the Aries downstairs, with a Netgear FS105v3 Fast Ethernet switch to force Aries to talk at 100Mbps. If I get such a setup going some time after Thanksgiving I'll post a follow-up report.