Which smart dimmer for magnetic transformers w/ mix of LED & incandescent

I'd like to replace all the existing dimmers controlling the low voltage lighting system in my house with Lutron smart dimmers. Simultaneously, I'll be replacing most (but not all) of the lamps with LED. The specifics are Tech Lighting magnetic transformers and Soraa Vivid MR16 lamps. I've tested this combination with my existing dimmers, which are about ten years old and appear to be Lutron Diva units. There is no buzz.

I had been unable to select Lutron smart dimmers up to now because they did not integrate with my other smart home components, all operating via a Smartthings hub. I gather that is soon changing, so I can select Lutron dimmers. I had previously tried two of your competitors' dimmers with the magnetic transformers and Soraa LED lamps and found they caused significant buzzing.

Can you offer guidance to me (and the electrician who tested the other two dimmers and will be installing the Lutron ones) about which Lutron smart dimmer can be used to avoid the buzzing, or what further information is needed to determine the answer to that question? Thanks for any suggestions.

For Caseta try the PD-10NXD-xx
Maestro Wireless- MRF2-6ND-120-xx
RadioRA2- RRD-10ND-xx

These are not the dimmers you are looking for. Unless your home already has a Lutron system (or you wish to have a larger Lutron system), these dimmers do not offer any a solid solution and are quite expensive compared to alternatives.

We have had several customers that wanted us to dim their 12V LEDs with Radiora dimmers. Mostly strips, but some fixtures, some lamps. A lot of this is under-counter lighting, but some sophisticated and interesting use of strips. The results have not been good.

Almost always, their prior installation been using PWM (pulse-width modulation) drivers for dimming, and those worked beautifully: no buzzing, very low light levels.

Lutron products are for a different world: high voltage, requiring a transformer driver. At high light levels, they are fine. At low light levels, the lights buzz. What's worse, they change light levels at both a high frequency low/high level (tiny flickering) and a low frequency (over several seconds).

• We have bought four different brands of driver (transformer), with no visible difference.
• Similarly, we have tried several dimmers with no difference: RRD-6NA, RRD-10ND, RRD-6CL, RRD-10D, RRD-6D.
• We even tried a GRX-PWM because it has PWM output, but it did not work, either. The current permitted on the PWM interface is too low to be useful. Moreover, the large size was ungainly and high cost made it not competitive.

Several lengthy consultations with Lutron Tech support (truly excellent) convinced me that Lutron does not have a good MLV or ELV solution for LEDs in this class. We love them for incandescent uses, though those opportunities are getting fewer.

Dimming MR16 LEDs can be a big issue since they are all being manufactured differently, and so the dimming performance will vary greatly from one to the next. Many LEDs on the market (including ones labeled as dimmable) have issues when placed on dimming controls. On top of that, MR16 LEDs are generally one of the toughest types of LED to dim. The issue with these lamps is due to the interdependencies between the lamp, transformer, and dimmer. Only certain transformers work OK on a given LED MR16 and even then, only certain dimmers will work, and even then the MR16 lamps generally have some shimmer as you dim down.

All of our recommendations can be found on the following application note. Anything outside of this application note is considered untested, and therefore we are unable to guarantee LED compatibility in those applications.

http://www.lutron.com/TechnicalDocum...ary/048559.pdf