Hey I just got one of these ballasts also. When I first got home I fired it in a separate silent room with a Yield Master II Supreme hood & cord set (15 ft) and a Hortilux 1000w HPS and immediately thought something was wrong with it. It sounded nearly as loud as 250w or so magenetic ballast and it just sounded bad. So I prompty returned to the store where I purchased it for further testing. We hooked up a 1000w Hortilux bulb (different one then mine) with a socket and 1 foot cord. Now it seemed much quieter, granted the store had a much louder ambient background noise. I was stumped, the display model on the wall was running a 600w MH conversion bulb and was DEAD silent, I mean no hum, nadda, couldn't even tell it was on beside slight warmth. So for further testing, we took the same 1000w Hortilux bulb and 1 foot cord setup and ran another new Solis Tek 1000w ballast from the box, this one made what we determined to be equal noise as my original. I left the store with my original ballast somewhat stumped, and I guess my expectations were just too high? I don't mind slight noise, but these are typically advertised as silent, just want to be safe.
I don't have any flickering bulb issues personally. I only observed that the 1000w Hortilux bulbs (digital compatible ones) made a medium high pitched ringing sound while the ballast was soft-warming the blub. One the bulb reached peak light output (2-3 min) the ringing vanishes. This was observed with 2 different bulbs and 2 different Solis Tek 1000w ballasts.
Mine runs pretty cool, even in a warm room I would say it's a cool as a 400w magnetic, maybe even cooler. In a cool room (~70 ambient) it barely feels warm to the touch.
Last problem I experienced... Using the standard 15 foot lamp cord provided with the Yield Master II Supreme from Sunlight supply I am getting pretty high RF interference. It's not affecting my satelittle or wifi, but it is very loud on AM radio and most annoyingly, it renders my Bluelab Guardian constant meter unusable. The ph seems stable, but the temperate goes from 73 to 36 instantly and back, while the ec goes from 2.3 (what it should be) up to 3.0 rapidly, incrementally and back down. I believe this is due to the cord being unshielded (not intended for digital ballasts) and it's causing the 15 ft cord to turn into a giant antenna. The only company that seems to provide a product targeted at this problem is Lumatek. They offer a RF shielded 15 foot cord set that can be directly soldered into the hood that it suppose to reduce the RF to 5 feet max. Can anyone else confirm a similar problem with a digital ballast? Anyone successfully remedied it with the Lumatek cord set? any personal experience here would be great.
http://www.cdgrowlight.com/Indoor-Growing-Products/Lighting-Accessories/Lumatek-Digital-Ballast-Cord-Set-LCSC190
Just my feedback, would love to hear from someone who knows more about the noise from the ballast. Is it possible 2 were bad? Should I push them to try a 3rd unit to replace it with? Thanks guys!
Can you even purchase the magnetic ones now? Everything I see is electronic/digital.