[podvrh]

I am just about to add a Bryston BP-25 to my set up.

This addition will allow me for the first time to use balanced cables.

My query relates to XLR wiring and use of the polarity selector when a source device connected to the balanced input of the BP-25 outputs on pin 2 the negative signal and on pin 3 the positive signal. This is not the standard today but until recently there was gear wired like this.

I have two pairs of Bryston 7B-ST mono amplifiers which will be easy to connect using a Y-cable. This will be female XLR to two male XLR. I have selected Mogami 2930 with Neutrik gold pin connectors in a metal housing. The pins are 1 for ground, 2 for hot and 3 for cold.

I have a Marantz CD-7 player with balanced outputs labelled 1 for ground, 2 for cold and 3 for hot.
I have a selected Mogami 2549 with Neutrik gold pin connectors in a metal housing. I have ordered a normally wired cable for use here. The wiring from hot to cold will not be crossed over at one end in this cable.

Now to my questions:
Am I on the right track here?
Do I now simply use the polarity invert selector every time I switch to the balanced input assigned to the Marantz CD-7?
Am I completely lost here?
Should I just cross over the hot and cold signal in the female XLR connector of the interconnect leads used with the Marantz CD-7?

What is the function of the "polarity invert selector"?

In advance thanks for reading this far and I look forward to your comments.

[brucek]

This is not the standard today

The standard, today, and any other day, is that pin 2 is hot (+ve) and pin 3 is cold (-ve). Yes, there are a few contradictions, but it isn't the norm.

I looked at the schematic for your Marantz CD7 and indeed it showed as incorrect as you've indicated. Sheesh, what's wrong with those people? Is it actually that way, or is the schematic wrong?

Even if you believe that Marantz could make such a rookie mistake, I wouldn't modify any cables to accomodate that device. I would keep all my cables as standard, and use the polarity switch to see what position offered the best sound.

brucek

[vegasdave]

From my understanding, Japanese manufacturers switch the hot and cold pins.

[podvrh]

I have another cd player, a Marantz CD-12/DA12.
I love my Marantz! This set is a transport with seperate dac,
The DA12 dac also has balanced outputs.
Surprise, surprise the output has pin 2 as negative (cold) and pin 3 as positive (hot).

The Bryston BP-25 has two balanced inputs both which will be used with the Marantz cd players.
But I can't A-B using two identical cds to listen for any difference unless I get my hands on another player with balanced outputs wired 2 as hot and 3 as cold!

I'm thinking the polarity selector must be there to compensate for components with balanced outputs, where the positive (hot) and negative (cold) signals are reversed.

Brucek, you are right I should not modify the cables. I would end up with a non standard cable pair that could be accidentally used elsewhere!

Any further diffinitive comments will be most welcome.