I also agree that VLAN separation helps with sound quality. But there are some gotchas. Read below. QoS not so much in my network. In theory QoS could even harm the sound quality. But I did not bother doing further tests QoS. Let me explain why.
Like anything else in the digital world, things are a little more complex than they look on the surface. And as I stated in my previous post they are system / environment specific too.
This Ubiquiti EdgeRouter X SFP router I recently started using for example is a really nice little device. It has just the right functionality I need. And when you power it up with a good LPS, it sounds great too. Changing the capacitors in the power section also brings up more goods, but that is more complicated than it sounds, because pretty much any better capacitors you install would be larger in size than the stock, and they won’t fit in the original case. That means you have to move the router to a new case too.
Let's look more into some of the capabilities this router has:
- It can do NAT in hardware. It boosts up the performance of the router and you get a throughput increase from 300 Mbps to 950 Mbps.
- It can do separate VLANs, and perform NAT / routing between them. That’s not something you see often on the consumer grade network devices.
- It can do QoS.
Now, how do those features relate to sound quality?
- NAT in hardware - pretty much all of our home networks have to perform NAT. NAT is translating the private IP addresses on our network (i.e. 192.168.x.x, 10.x.x.x, etc.) to public / routable IP addresses on the Internet. Doing this in hardware means that it is not done by the CPU on the router. Instead, it is done by a hardware chip. A hardware chip can do this much faster and much more efficiently. This type of CPU offloading helps the sound quality in two ways - first, it lowers the latency a little bit; and second, the CPU has to do less. The latter means the CPU is drawing less power, which if I was to speculate here probably means less noise. It also leaves more CPU capacity for the other processes.
- The VLAN separation is easy to explain and other people have done it here before me. If you have your server/streamer on a dedicated VLAN, it would not receive any of the broadcast traffic from the rest of the devices on your network. That means the CPU and the OS have to do less. That essentially turns into better sound quality.
- What happens if we enable QoS on this particular router? Well, Qos is not supported in hardware offloading, so the router would have to do heavier CPU utilization. And if my speculation above is right, that leads to more noise. I am not planning to go into the details of how QoS works, but I would say that there is no advantage of doing QoS in my network, so I can only cause more harm by enabling QoS.
But that is in my network with this particular router. The point I am trying to make here is that
these are not universal settings that work universally on any device and in any network. An old consumer router, for example, with an older CPU, may generate more noise to do the VLAN switching - and that can easily outweigh the benefit of VLAN segregation.
I would not worry about the fact that audiophile switches don’t have layer 3 / VLAN capabilities. That’s probably even better. Leave the routing functionality to the router. I would rather keep the audiophile switches simple, so they can do what they are designed to do better. If you connect an audiophile switch to a port on a router that has a dedicated VLAN configured and DHCP enabled, you don't need the switch to be able to perform any special functions.
The most common question I got asked (privately) after my first post was:
Q. The Ubiquiti EdgeRouter X SFP has a 24V power supply. How do you power it up with 12V?
A. The Ubiquiti EdgeRouter X SFP comes with a 24V / 2.5A (SMPS) power supply. However it supports 9-26V DC on the input. So, yes, you can power it up with a 12V DC LPS like I mentioned in my previous post. And, no, it does not consume 60W. It is designed to provide PoE to multiple devices, that’s why the specs call for 60W. The way I use it, consumes less power than my etherREGEN switch. Give it 12V / 1A or more, and you would be fine.
Nenon, In your description above, are you still using the modem provided by your ISP? I have Att (fiber optic) and I think their "Gateway" modem box must still be used.
I am not sure about Att. I use Comcast / Xfinity. They give you a crappy cable modem / router / Wifi all-in-one device. It's much easier for them to manage their users if they were all using the same cable modem, firmware version, etc. But they also have
a list of supported devices you can bring on your own.
Yes I did, in the final version of the Extreme this was a sideways move, though in early versions a definite upgrade. Do note the JCAT Femto card provides the option to power it from an external power supply which again would give you a degree of voicing. However external powersupplies used this way are able to damage the Extreme beyond our control.
So, on the Extreme, you use the onboard NIC with the Telegartner GOLD M12 switch, and that sounds better than utilizing a good external PCIe card like the JCAT? I was under the impression that the Extreme was highly tweaked to utilize fiber via the Startech PCIe card. And I thought switching to the onboard NIC with the Telegartner GOLD M12 switch may mean going back to the test lab to re-evaluate copper connectivity. But maybe I am wrong about this.
BTW, I am with you on the power supply thing. Tweaking your whole system with multiple rails of the same design power supply gives better results than using a mixture of many different power supplies.
If the capability of a commercial managed switch is mandatory for your audio setup, you may consider to send it to one of the diy shops for tweaking, such as giving it a LPS or installing better internal ocxo modules.
BTW, that is next on my list to try on the Ubiquiti and cable modem. But it would take some time, because I want to learn how to do it myself, and there is a learning curve associated with that. I would be happy to report my findings when I do.
