ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Hey Beoworlders,
This might be a bit elementary, but can someone help me confirm the following?
In reference to B&O's newer RJ45 PowerLink connections...
Pin 6 = Audio R Signal
Pin 8 = Audio L Signal
If Pins 3 and 7 are both "Signal Ground", does it matter which channel they are connected/assigned to?
Do the strands from Pins 3 and 7 need to connect at any point, or can each of the 4 strands be completely shielded off from each other?
MANY THANKS!!
The standard (T568B) wiring for an RJ45 to RJ45 patch lead would be:
1 - white/orange2 - orange3 - white/green4 - blue5 - white/blue6 - green7 - white/brown8 - brown
We can see from this that pins 1&2, pins 3&6, pins 4&5 and pins 7&8 each form pairs, so to answer your question, pin 3 would be the ground for Audio R and pin 7 would be the ground for Audio L.
Whether the two grounds connect at any point depends on the type of plug at the other end of the cable. If it is RJ45 at both ends, then no, they don't need to be connected anywhere. If the other end is an 8 pin DIN (old powerlink connector) then both these grounds would be connected to pin 2 on the DIN connector as there is only one signal ground available.
Hope this helps.
Martin.
Thanks, Martin. Makes sense, and I appreciate the answer!
Last question, what if the termination on the other end are RCA male plugs? Would the grounds need to somewhere down the line?
My instinct says no, but multiple diagrams say otherwise.
Hi Earle.
There's still no need to connect them within the cable, but...
Out of interest, what is the application? Is this to connect the RCA outputs of a device to B&O speakers with RJ45 connectors, or to connect a B&O device with RJ45 powerlink outputs to a non B&O amplifier / active speaker?
Well, it's kind of a pre-emptive question. Basically, it will be a non-B&O pre-amp (RCA) to B&O speakers (RJ45). I'm planning on purchasing a pre-amp (still not decided, but likely the Outlaw 975), but I'm not exactly sure if I want to create custom exact-length cables, or build a simple small box with RJ45 inputs on one side, and the appropriate RCA outputs on the other - I just need to know which pins connect to what.
Back to the issue-at-hand,..
I understand that I'm going to have to use shielded cables at some point throughout the connection, but does that mean the shielding, which will be in contact with the RJ45 metal connector and ground of the RCA connectors, be in contact with both pins 3 and 7 at the same time?
I guess I just can't get my head wrapped around all the cross connections of the ground wire... it seems like a bunch of short circuits to me... plus, I'd hate to short circuit anything for-real.
I'm pretty old-school with my technical background, so you'll have to excuse my non-computer generated sketch. Anyway, is this basically what I've got to work with?
(thanks again for the help btw!)
Earle:is this basically what I've got to work with?
Yep, looks perfect to me.
Hi Riverstyx,
I've got a similar question.. I've just recently purchased a BeoSound Moment and want to connect the output of this to a non-B&O Amp (i.e. Marantz AVR NR1604). The Marantz AVR will then output to BeoLab 1 speakers which are connected to the Pre-Out outputs.
The cable from the BeoSound Moment to the Marantz AVR will need to be around 13m long so I'm looking to build it myself. I understand the wiring diagram but want some advice on what cable to use as a starting point. That is, can I take a Cat 6/Cat 7 network cable, cut one end and solder on Left and Right RCA connectors as per Earle's diagram? Or are Cat 6/Cat 7 not a good starting point for this application?
Thanks in advance!
SuperM:can I take a Cat 6/Cat 7 network cable, cut one end and solder on Left and Right RCA connectors as per Earle's diagram?
Yep, as long as you use S/FTP cable (that has a foil screen around each pair, as well as an overall braided screen), regardless of whether it's Cat6 or Cat7, it should work fine.
Just watch out for the fact that some S/FTP patch cables use aluminium for the braid and you'll have a hard time soldering this to anything!
If you want an easy, solderless solution, you could always use an RJ45 to twin RCA cable, plus a long RCA to RCA extension (or an RJ45 to RCA cable, an RJ45 coupler, and a long S/FTP patch cable).
Hi Beoworlders,
Thank you so far for an amazing site. Full in interesting things to read.
I have a question re RJ45 to RCA.
I have been asked to make a lead and I am unsure if the connections in this diagram suit me for what I am wanting to do.
Simply: B&o Core with PL / only RJ45 to RCA pin configeration.
Next: Non B&o pre-amp with RCA to B&o Speaker with RJ45. Are the pins the same?
Next: B&o device with RJ45 (PL) to 8 Pin Din to B&o Active speaker? Does the RJ45 have the trigger voltage needed to activate the speakers, EG: Beolab 3 or Beolab 4000?
Getting back to the diagram in this discussion. Yes we have L+R signal and L+R ground, but we also have a ground to consider. This is used for the static protection of the B&o products. If I use a cable that has all 4 connections and a an earth, do I simply join that to the end in the RCA plug?
Thank you for your help. These leads have given me some headache as I do not own the B&o Core and can not test before giving the lead to my customer who is in another state, 800km's away.
Regards
Greg
Ex B&o Club 1972 to 2010.