older power supply?

[rockgad]

I recently purchased a 2 year old chassis and power supply with 2 n72's installed. Sounds great and wanted to add more pre's to the chassis and read that the older power supply might have to be swapped out. I'd like to add 2 j99's next and fill in the rest with a12's down the road. How do I determine the version of the power supply? Please advise me on the best approach for this.
Thanks ,
Rockgad

[rockgad]

Nobody can answer this? Anybody? Tim?
Thank you,
Rockgad

[tpryan]

You should just add modules until there's a problem. There probably won't be, especially if you're only planning to add J99s and A12s. If you fill the chassis with current-hungry N72s and C84s and happen to have a sagging AC line, you might experience hum on the N72 modules with some PS02s.