Sonifex CM-LUR1 Balanced to Unbalanced Audio Converter
This product allows the connection of a stereo balanced line input via RJ45 with StudioHub+™ pinout to a stereo unbalanced output on stereo phono connectors.
It is transformer balanced, with a 2:1 ratio, so 6dB of attenuation is added to the input to help interface with the lower signal levels associated with consumer outputs.
This unit is a passive version of the RB-LU4 (though only 1 x stereo channel), and provides you with an alternative to having to interface a balanced output to an unbalanced input via specialist cables (either by shorting the non-phase to ground or disconnecting it).
It is particularly useful where a shared balanced audio feed needs interfacing to an unbalanced input on one or more pieces of equipment. Using a CM-LUR1 or CM-LUX1 galvanically isolates the audio, allowing you to connect via phono cables to an unbalanced input without compromising the distributed feed.
Block Diagram
Connectors & Controls
Analogue Inputs
The stereo analogue input is on a female RJ45 connector with the following standard StudioHub+™ pin assignments:
| Pin No | Connection |
| 1 | Left Phase |
| 2 | Left Non-Phase |
| 3 | Right Phase |
| 4 | Ground |
| 5 | N/C |
| 6 | Right Non-Phase |
| 7 | N/C |
| 8 | N/C |
RCA Phono Analogue Outputs
This unit uses a stereo unbalanced line output on a RCA phono connector with the following connections:
| Pin Type | Connection |
| White Tip: | Left |
| White Screen: | Ground |
| Red Tip: | Right |
| Red Screen: | Ground |
CM-LUR1 Technical Specification |
|
Audio Specification |
|
| Input/Output Level Ratio: | 2:1 |
| Input/Output Impedance Ratio: | 4:1 |
| Max Input Level: | +28dBu |
| Max Output Level: | +22dBu |
| Frequency Response: | 20Hz to 20kHz, +0/-0.5dB |
| Noise: | <-115dBu A-wgtd |
| Distortion Ref +8dBu (Output): | <0.01% |
| Common Mode Rejection: | >80dB |
Connections |
|
| Balanced Line Input:: | 1 x RJ45 female StudioHub+™ pinout |
| Unbalanced Line Output: | 2 x RCA phono connectors |
Equipment Type |
|
| CM-LUR1: | Balanced to unbalanced audio converter, RJ45 input |
Physical Specification |
|
| Dimensions (Raw): | 7.7cm (W) x 8.3cm (D) x 4.2cm (H) 3.0” (W) x 3.3” (D) x 1.7” (H) |
| Dimensions (Boxed): | 12.7cm (W) x 22.9cm (D) x 7.6cm (H) 5” (W) x 9” (D) x 3” (H) |
| Weight: | Nett: 0.22kg Gross: 0.33kg Nett: 0.49lbs Gross: 0.73lbs |