Digital coax

[rikardo1979]

http://www.wbt.de/english/products/a...r-topline.html

OP2

[NRG]

AFAIR somebody measured those on DIY audio and found they didn't measure 75ohm, anyhow, what about the socket they plug into length does matter btw due to reflections caused by the impedance mismatch.

[Barry]

http://www.wbt.de/english/products/a...r-topline.html

OP2

If they are designed to have a characteristic impedance of 75 Ohm, this impedance will only be maintained if the plugs are mated with WBT's own non-standard RCA sockets. The great majority of CD players use a standard RCA socket for the coaxial digital output.

[NRG]

Yup, apparently they claim 75ohm characteristic impedance with their matching RCA socket, so if you have to use a special socket (probably an expensive one at that) you may as well use a BNC connector that was designed for the purpose from the outset, not some over priced bling. Just sayin......

[Barry]

AFAIR somebody measured those on DIY audio and found they didn't measure 75ohm, anyhow, what about the socket they plug into length does matter btw due to reflections caused by the impedance mismatch.

I was referring to the length of the plug. The impedance mismatch is 75 Ohm to ~ 35 Ohm at one end of the plug, and ~ 35 Ohm to 75 Ohm on the other side of the connector. Since these two mismatches are in the opposite sense (the reflection coefficients are equal but have opposite signs), they will partially cancel.

Sometime ago I posted the actual calculation; despite the near 2:1 impedance mismatch at the plug and at socket, the overall total mismatch is lower.

Experimenting with cables having a characteristic impedance of 75 Ohm, 50 Ohm and cables having an unspecified impedance, I found the 75 Ohm cables sounded better.
.