All connections were extensively measured and the report was delivered and stored. Stranded, solid, CAT 5, CAT 5E, CAT 6, CAT 7 etc. We measured cabling with very expensive equipment and saw differences between brands, types of cables (UTP, FTP, STP, SFTP.) and even iron cables that were introduced (but very soon these were excluded). As I am audio hobby guy since I was a child of course I gained experience for the hobby as well. We measured cabling and connections in polluted industrial environments. Hi I have worked for a very long time in a business where ethernet was the most common cabling besides optical fibers. No “switching regulators” are employed in the analog section. The analog power supply section of the DVP-NS999ES is entirely “linear” and has a 60Hz power transformer. However the DVP-NS999ES does have ***entirely*** separate power supplies for its digital vs.

Later high-end disc players (Sony DVP-NS999ES for example) have direct electrical connections between the transport section and the analog section. My experience was it sometimes caused issues that didn’t occur in non-optically-isolated CD players. However this eventually fell out of favor. The place where reducing noise in the desired signal is most important is in the analog section.ĭuring the 1980’s and 1990’s several CD player manufacturers experimented with internal optical isolation between the CD transport and the DAC/analog output section. Keep in mind that digital signals are relatively immune from being degraded by noise or other interfering signals. This provides a totally isolated data path between the two RJ45 jacks.Ĭlick to expand.This is a good point and is especially relevant when adding an external device such as an isolator, filter, or even a specialized “audiophile” cable. The SFP slot holds a fiber transceiver module appropriate for the desired type of fiber cable (single-mode, multi-mode, etc.) Two such media converter devices may be connected back-to-back with a fiber cable in between them. These devices typically have one RJ45 jack and one SFP slot. Look up “media converter” on ebay or alibaba to see examples of low-cost commercial devices which do this. When ***total*** electrical isolation is desired it might be better to use “Ethernet-to-fiber” media converter devices. What is the value of adding an ***additional*** external magnetic coupling transformer? Some manufacturers of RJ45 jacks offer models where the magnetic coupling transformer is embedded inside the housing of the RJ45 jack itself. My observation of numerous devices with 100MHz Ethernet connected through an RJ45 jack is that ***all*** of them contain an internal magnetic coupling transformer positioned between the PHY transceiver IC chip and the RJ45 jack. Is the sound the same, better, or worse with a change to the circuit design? However since this is for audio, one could always let one's ears be the guide. Modeling and measurements would be advised to help understand the consequences. It might help or it might hurt performance. If you are asking about adding similar circuitry on the primary side of the transformer then the effects of that would have to be evaluated. The component values and circuitry are likely particular to the design shown in the schematic. The resistors are probably chosen to dampen unwanted transformer output signal imperfections and dissipate their energy as heat in the resistors. The purpose of the 75-ohm resistors and cap connecting transformer center taps to ground kind of looks to me like a way to help dissipate high frequency components of transformer phase imbalances and or common mode coupling through the transformer. For some kinds of conducted RFI/EMI noise it may be necessary to do some experimentation and measurements to find out what works best in the particular circumstances where there is a problem.

Gigabit ethernet optical isolator