This question is specifically for Greg Norman, but if anybody else cares to chime in, feel free.

Hey Greg, how do you guys hang your oscilloscope off of your patch bay? Is is normalled to anything? Like a pair of aux outs, or monitor outs, from the board. Or is it just hanging there on it's own?

I'm kinda muddling through hooking my oscilloscopescope up and I want to hook it up to my patch bay.

Also, do you run into any problems with impedience patching, say 2 channels of a tape machine into it? I'm asking, because I'm wandering if the distance of the cables getting from the deck to the patchbay, then to the scope would cause any problems.

thanks a lot for any information anyone cares to give me.

I originally wired my patchbay with the scope half-normalled to the main outs. This caused all kinds of problems, not sure why, but I just clipped the half-normal and simply patch into the scope whenever I need to.


mike

Elite (studio A)- We have it normaled to the control room monitor send (pre volume control). It's on the patch bay so we can use it for other things.
Series II (studio B)- The oscilloscope is off the Studio send, also on the patch bay.

There shouldn't be any problem with connecting to it.
Some gear will have balanced output drivers that don't like shorting the cold leg to ground though.
We wire ours + to pin, - to the case of the connector, lifting the ground.

awesome, thanks.

[quote="greg"]
We wire ours + to pin, - to the case of the connector, lifting the ground.[/quote]

Greg, doesn't this mean you're connecting your (-) from the X channel to the (-) from the Y channel through the scope body ... compromising balancing?

Phil

Which scopes do you guys use?

ptay wrote:

greg wrote:We wire ours + to pin, - to the case of the connector, lifting the ground.

Greg, doesn't this mean you're connecting your (-) from the X channel to the (-) from the Y channel through the scope body ... compromising balancing?

Phil

The oscilloscope's inputs are basically unbalanced, so the two (-) sends are grounded there. If you have isolated inputs on your oscilloscope (case of the BNC connector lifted from ground), you would connect it the same way.

Greg,

If the scope's inputs are the usual style ... with the shield common to both inputs, and if you do not buffer the line coming off your monitor output, then you are effectively screwing the (-)'s together. I.e. they aren't balanced, and they are not as 'stereo' as they ought to be.

Your L+R negatives are both hot, right, and if the console in question uses relays to switch the monitor paths, you may well end up with a situation where the two (-) lines of your monitor path are hard switched, say, to your stereo mix, and along with that all the inputs to your 2-track gear could be fused together (unbalanced) at their negative (-) hot terminals.

I'd be curious to know if you get away with it because you have buffers somewhere in the path from your stereo mix to your scope+monitor inputs. If there's no buffer, then you're screwing your 2-mix, among whatever else you're monitoring, up royally.

Phil

ptay wrote:Greg,

If the scope's inputs are the usual style ... with the shield common to both inputs, and if you do not buffer the line coming off your monitor output, then you are effectively screwing the (-)'s together. I.e. they aren't balanced, and they are not as 'stereo' as they ought to be.

Your L+R negatives are both hot, right, and if the console in question uses relays to switch the monitor paths, you may well end up with a situation where the two (-) lines of your monitor path are hard switched, say, to your stereo mix, and along with that all the inputs to your 2-track gear could be fused together (unbalanced) at their negative (-) hot terminals.

I'd be curious to know if you get away with it because you have buffers somewhere in the path from your stereo mix to your scope+monitor inputs. If there's no buffer, then you're screwing your 2-mix, among whatever else you're monitoring, up royally.

Phil

The sends for the oscilloscope, from both of our consoles are unbalanced to start with. They aren't used for anything else (elite has a pre control room monitor pot output for this purpose). Besides, you don't lose stereoness by terminating balanced signals to an unbalanced load. You do it all the time in the studio.

The problem is with consoles that don't have a cute scope output.

Some older consoles have very raw, and this is sometimes why they're loved, ways of routing signals.

The point I was trying to make is that some consoles share copper for all the monitor sends. The monitor sends are selected with relays. In this console, connecting your L+R together, or even unbalancing, will have effects on all of the other monitoring equipment. And indeed anything you've got hooked up to your 2-mix, like a snazzy tape machine that is hard wired to the 2-mix that your monitor router just switched into with relays (ie copper on copper action).

Even if you're unbalancing a signal at the end of a long cable for all of the other devices that are in parallel to share, via that long cable, serious problems will be introduced. This isn't even a termination, if your monitor amp inputs are wired in parallel with a piece of gear on the other side of the studio that is unbalanced. It's a ground loop to be sure.

If the console does not have a buffered output, or even if it does but you want to be able to plug your scope into anything while maintaining a high-impedance affect-free close inspection, you absolutely need a differential buffer amp, with a wide bandwidth including DC voltages.

A transformer is a second option, though without the bandwidth. The worst option is plugging the unbalanced scope into shit that is perfectly, utterly balanced.

Just thought I'd keep this thread going because it's not as straightforward as I, and no doubt others, wish.

Phil