TRS inputs on MBox

[Marker]

Need some help with the TRS inputs (Source 1 and 2) on MBox. I understand each Insert (1 &2) can use a "Y" cable (Single TRS to 2 individual TS ends) in order to send and receive through a single Insert.

The MBox Basics Guide indicates that to record a stereo source, run Left signal to Source 1, Right Signal to Source 2 (or vice-versa?). Question is - if Source 1 and 2 are TRS inputs, could I use the same type of Y cable - sending L signal to the tip, and R signal to the Ring, using only Source 1?

This way, you could use only Source 1 or 2 (not both) and still get a stereo signal.

Likewise for the 2 Line Outs. MBox guide says use Line Out 1 for Left signal, Line Out 2 for Right signal. If these are TRS outs, wouldn't a Y cable do the trick here? (Get the L signal from the tip, R signal from the Ring, from a single Line Out.)

Or is it simply that the Source TRS and Line Out TRS work differently than the Insert TRS?

Thanks for any help!

[max cooper]

The main thing to understand here is that you don't get something for nothing. I'm not that familiar with the Mbox, but it looks like there are two inputs that are the XLR/TRS 1/4" type. I'm sure you can also plug a T/S type 1/4" connector into inputs 1 & 2 as well.

If you could run a right and left input to EACH input 1 & 2, that would mean you have 4 channels of input on the Mbox, which we know is not the case. I gather you understand this since you qualify the question with: "not both"

Sometimes a T/R/S connector is used for stereo (tip = ch. 1/ring = ch. 2/sleeve = signal ground).

Sometimes a T/R/S is used instead of an XLR connector to make a balanced connection.

Sometimes a T/R/S connector is used at an insert point (tip = in/ring = out/sleeve = signal ground)

In the case of the insert points, if you had something like an RNC which also supports T/R/S insert cabling, you could use a single pair of cables to go ch. 1 to/from and ch. 2 to and from. This not only keeps cabling to a minimum, it also saves on front/rear panel real estate on small boxes like the Mbox and the RNC.

As far as the line outs are concerned, the Mbox's line outs SUPPORT T/R/S balanced outputs, which is not the same as saying that the line out signal is BALANCED. In the case of most systems where the Mbox is used, a balanced signal would likely be unnecessary, as it's doubtful that any great distance is going to be traversed by the line out signal, except maybe in the case of a live performance situation. I'm not saying definitively that it's not making a balanced signal, just that it's doubtful Digi would use up box space and resources to support such a network.

To put it simply, in answer to your final question: "Or is it simply that the Source TRS and Line Out TRS work differently than the Insert TRS?"

Yes.

[tele_player]

The Mbox has balanced outputs on TRS jacks.

[Marker]

Thanks Max.

That was my first thought - you don't get something for nothing. I was holding out hope that the MBox would consider a Left/Right signal as a single, combined input.

It would make more sense though that the T/R/S inputs are used for a Balanced connection - in case you are running a length of 1/4 " cable directly into the MBox.