I've been looking for a couple of 600w ballasts myself and have done a LOT of reading, other than the one post above, I can't find anyone saying anything bad about the Solis Tek ballasts. I'm currently still running 2 400w CMH bulbs in magnetic ballasts and it's really not getting the job done. 2 600's will do a much better job for my space. The ST ballasts will also allow me to upgrade to 600w DE if I decide to go that route.
On the issue of dimming, I considered buying 2 ST 1000w ballasts and running 600w lamps on the 600w setting. Since I wasn't sure if this was a good idea, I emailed ST and this is the repy I got (just got this today)
That's a great question!
We believe in letting the customers know the pros and cons of dimming as they are there for luxury and convenience but not true efficiency. In this case dimming down a 1000w lamp to600w/400w would be more efficient choice as the lamp would be driven by the same output voltage even though it is being under driven by wattage. While you may operate a 600w lamp on the 1000w ballast on the 600w setting, the voltage differences would play more of a role in accelerated degradation as compared to wattage differences.
Here's why:
All 1000w lamps/ballasts were created with a operational voltage of 250v to the lamp (this is the output power from the ballast, not input power). 600w/400w lamps/ballasts were designed with an operation voltage of 125v to the lamp. When a 1000w ballast is changed to the 600w or 400w setting it does not step down the operational lamp voltage, this goes across the board for all ballasts and lamps as that's how they were designed.
If you are using our ballast and lamp you can dim the lamp down without sacrificing any spectralshift, unfortunately we cannot guarantee that with any other combination but our own. This is due to our lamps (pulse start) and ballasts being tuned for the same operating frequency thus resulting in higher efficiency, performance, and longevity.
Hope this helps answer your question!
SolisTek Staff
I think I'm just going to get 2 600w ballasts and be able to upgrade to DE if I decide to go that route.