The RDL RU‑MX4L is the ideal choice in many applications where a combination of balanced and/or unbalanced line‑level signals needs to be mixed. Balanced connections use XLR connectors. Unbalanced signals are coupled through phono jacks. Each of the four RU‑MX4L inputs can accept either a balanced XLR line‑level input or an unbalanced line‑level phono jack input. The unbalanced phono jack LINE OUTPUT from one RU‑MX4L may connect to the unbalanced input of other equipment, or may be connected to the DIRECT input of another RU‑MX4L or an RU‑MX4 to expand mixing capabilities. Up to 3 RU‑MX4 type mixers may be rack mounted in a single rack unit using an RDL RU‑RA3HD rack adapter. The RU‑MX4L provides one balanced output, switchable for mic or line level. Audio levels are adjustable on the front panel. Each input channel is equipped with a front‑panel dual‑LED VU meter that follows standard VU ballistics. The final mix is displayed on an LED string VU meter featuring a visually comfortable arc motion. A factory installed output isolation transformer is available by ordering the RU‑MX4LT.