Clint Goss
Member
I frequently need to send a balanced XLR signal to an unbalanced destination. This needs to be done on the fly in my performance rig (Ableton Push 3 and a Sylphyo wind controller rendered through several hardware modules), depending on the house system at the venue and the gear of other performers that are running through my rig.
My major confusion is: How do I tell whether to tie pin 1 to pin 3 at the XLR source end?
Some manuals I have warn that doing it wrong can cause distortion or even damage the output stage of the source device. An example of this warning is in the manual for my RME Babyface Pro FS:
OK, so that implies that if the manual says that the XLR output is servo-balanced, then Pin 1 should be tied to Pin 3.
All other gear I have encountered, at best, describes the output stage variously as:
Could someone identify, for the above terms (and maybe any others that I've missed), whether to tie Pin 1 to Pin 3 at the source end??
Also: What would you suggest if the documentation is silent on the design of the output stage?
For reference, I think these are my choices for wiring adapter cables:
As I understand it, Case C, using a twisted pair cable and routing the negative / cold / Pin 3 to the shield of the destination will get at least part of the Common Mode Rejection (20-30dB) that a fully balanced connection would (60dB). I am hoping I could use Case C in any situation where Pin 3 can be tied to Pin 1.
The main reference for this is: Rane Technical Staff, 2015, Rane Note #110, Sound System Interconnection, Figure 4, Cases 3 and 5.
Thanks for any feedback you could provide!
My major confusion is: How do I tell whether to tie pin 1 to pin 3 at the XLR source end?
Some manuals I have warn that doing it wrong can cause distortion or even damage the output stage of the source device. An example of this warning is in the manual for my RME Babyface Pro FS:
The short circuit protected, low impedance XLR line outputs do not operate servo balanced! When connecting unbalanced equipment, make sure pin 3 of the XLR output is not connected. A connection to ground might cause a decreased THD (higher distortion) and increased power consumption!
OK, so that implies that if the manual says that the XLR output is servo-balanced, then Pin 1 should be tied to Pin 3.
All other gear I have encountered, at best, describes the output stage variously as:
- Cross-coupled
- Transformer-balanced
- Active
- Passive
- Electronically balanced
- Servo-balanced
Could someone identify, for the above terms (and maybe any others that I've missed), whether to tie Pin 1 to Pin 3 at the source end??
Also: What would you suggest if the documentation is silent on the design of the output stage?
For reference, I think these are my choices for wiring adapter cables:
As I understand it, Case C, using a twisted pair cable and routing the negative / cold / Pin 3 to the shield of the destination will get at least part of the Common Mode Rejection (20-30dB) that a fully balanced connection would (60dB). I am hoping I could use Case C in any situation where Pin 3 can be tied to Pin 1.
The main reference for this is: Rane Technical Staff, 2015, Rane Note #110, Sound System Interconnection, Figure 4, Cases 3 and 5.
Thanks for any feedback you could provide!