Are my CAT5 and router my weak link?

08-14-12: Jeffatus
Well, I wonder if I make the computer connection to router wireless, then connect the computer direct to the DAC (bypassing the switch altogether).... Does anyone see anything I missed?

That's a good question, given that it sounds like the computer is either a laptop or a desktop with a wireless adapter. Here are a couple of points to consider, though:

1)In doing that essentially what you would be doing is substituting one significant generator of digital noise (the computer) for another (the router). And quite possibly the computer is considerably worse in that respect than the router. Having a network switch between the computer and the DAC could conceivably still provide significant noise reduction benefit, with respect to computer-generated noise in this instance.

2)Changing to a wireless connection between the router and the computer might slow down your internet connection speed, depending on the speeds of the internet connection and the wireless link. If you frequently have occasion to download large files that might be a significant consideration.

Regards,
-- Al

Jeff - Sorry this has become a bit complicated. Al is making a lot of good points. IMO, many of the possibilities he's raised suggest that you should experiment. Some of the experiments we've discussed are free and the others are relatively inexpensive.

IME, computer audio is filled with mysteries and magic. So sometimes it's difficult to know the best approach without experimentation. Hopefully, you'll find it fun.

Keep in mind also that you are likely to get good results with any of the approaches we've discussed, in light of the fact that you have an excellent dac. So we're really talking about the last few % of sound quality.

If you do nothing else, use Cat 7 for the hard lines. If you decide to experiment, keep us posted with the results.

Bryon

To SGR,

I purchased my Opto-Isolator from Black Box (linked below). I am using the 100MB unit as it offers more than enough bandwidth for audio purposes but they do sell GB ones also.

http://www.blackbox.com/Store/Detail.aspx/Ethernet-Data-Isolator-10BASE-T-100BASE-TX/SP426A

By using one of these Isolators you are eliminating any noise from propagating beyond the point of its location. There is no need to rewire your LAN again.

For our purposes (Audio) CAT5 is more than sufficient in this configuration (with Isolator) because at the end of the day these other cables are offering nothing more than additional shielding from interference. The ones and zeros could care less about this interference unless its so severe as to cause them to no longer be the same ones and zeros at which point you obviously have other issues to worry about.

I have done some fairly through testing of this unit prior to using it in my own setup and found no difference in data transfer rates or ping times with the device Inline/Not Inline. I also conducted CRC Checksum testing of data that passed thru the Isolator verses the same data that was copied without the Isolator and found it was 100% the same in both cases.

Eniac, thanks for providing the info about the opto-isolator, which certainly seems like something that could be beneficial in many setups, and that apparently has no downside aside from its cost.

However, while it figures to be something that would eliminate groundloop-related noise, without further technical information on it (which I couldn't find via a Google search) I'm uncertain as to the degree of effectiveness it would have with respect to source-generated noise that may be riding on its input signal. For instance, some amount of stray capacitance will exist between the electrical parts of the device, that may to some degree allow noise to bypass the opto-coupler device. Also, I note that its intended purpose is described as surge protection.

Also, I would not necessarily conclude that it would make cable upgrade redundant, because the existing unshielded cables could conceivably radiate noise that would bypass the device. That could occur by radiation into the power wiring, or directly into system components or cabling. Bryon's experimental results would seem to support those possibilities.

Regards,
-- Al