Anybody know if Dolby A 361's are pin 2 or 3 hot?

[Jonk]

I don't have a manual and I'm ready to wire these things into the patch bay, so I need to figure out which pin is hot.

I'm trying to measure between Pins 1 and 2 and then 1 and 3 of the input side to see if I can get a resistence reading but now I'm thinking that might only work if there's an input pot. And I'm not getting any reading on the DMM anyway.

Anyway, does anyone have a manual or know whether pin 2 or 3 is hot? Or how to test that?

[paully]

Jonk,

Contact Warren Dent via e-mail at:

warren@frontendaudio.com

for a definative answer.

Paul

[Geoff_T]

Originally Posted by Jonk

I don't have a manual and I'm ready to wire these things into the patch bay, so I need to figure out which pin is hot.

I'm trying to measure between Pins 1 and 2 and then 1 and 3 of the input side to see if I can get a resistence reading but now I'm thinking that might only work if there's an input pot. And I'm not getting any reading on the DMM anyway.

Anyway, does anyone have a manual or know whether pin 2 or 3 is hot? Or how to test that?

Hi

Just a thought... I don't think it matters because, unless there's a deliberate phase reversal (which would mess it up either way)... what goes in is what comes out.

[Jonk]

Thanks Guys,

Geoff, are you saying that because of the nature of the electronics in a Dolby 361 unit, or in general?

I've always tried to identify which pin is hot w/ other gear.

[Geoff_T]

Originally Posted by Jonk

Thanks Guys,

Geoff, are you saying that because of the nature of the electronics in a Dolby 361 unit, or in general?

I've always tried to identify which pin is hot w/ other gear.

Hi

In general....

If you think about it... what company would put an intentional phase reversal between input and output?

So, go in on 3, come out on 3

Go in on 2, come out on 2

If they don't swap over, there's little point in worrying about it!

Mind you... I'm talking balanced pro audio here....

Unbalanced units are a whole different ball game...

[brianroth]

Geoff is dead-on, but to answer the original question, my 361 manual sez "pin 3 high".

Bri

[David Kulka]

Geoff and Brian are dead on but there's one small gotcha with 361's that used to bite people on occasion.

In record mode the line in passes through an input transformer, then through the NR encode circuit, through an output transformer, and to the recorder. The line in also gets "multed" to the monitor output, without passing through a transformer.

The gotcha part is that in the above example, line in is connected directly to monitor out. If the Dolby record input is fed from an electrically balanced source and monitor out of the Dolby goes to an unbalanced monitor in, level problems and distortion can crop up. Without the 361, this would not happen.

The above example contains a lot of ifs, but it's a problem that troubled people at times. The main thing to remember is, avoid connecting a 361's monitor output to an unbalanced input.