I'd like to switch the lamps/bulbs powered by my Legacy Unison DR rack to LEDs. Is the rack compatible? Will this work?
This is a complicated question, because the answer is "it might." Most Unison DR racks are using D20 modules, which were originally designed with resistive incandescent loads in mind, and LEDs are a capacitive load. The D20 also functions best with a minimum 100w load. Often we see the load drop below this threshold when LEDs are installed, which cause flickering, and popping on/off, especially when dimmed below full intensity. Additionally D20 modules are a forward-phase dimmer, so even if an LED is marked "dimmable" on the box, they might only work on reverse-phase dimmers and thus are not compatible with this rack. Check with the manufacturer of the LED if you're unsure which technology it uses.
ETC does test LEDs for functionality with our systems at no cost. We have compiled our findings into a searchable LED Dimming Compatibility database. Before purchasing we recommend searching this database to see if there's one we've tested that should work in your system. If you don't find a make/model you're looking to use, we have a form you can fill out and send in with samples for us to test. Please note this database is not an "approved" list, but rather information about our findings. We leave it up to you to decide which LED to use, and you may find that results on site may differ from our testing.