Thanks! I had the same observation as you- never noticed much of a difference. I bought this 1210 because of four reasons: 1, I'm an electronics geek, 2, for my analog recording studio, 3, it was one of those once-in-a-lifetime deals that you find on eBay (old man passed away...estate sale reseller...pristine condition!), and 4, I'm a fan of older Furman products back when they were made in either Greenbrae or Petaluma (not ch*na - I *loathe* that new..."stuff"). For amplifiers I also didn't hear much of a noise difference. The conclusion I've drawn is that this would be most effective for condenser mics, or especially a digital recording studio, since digital picks up e-v-e-r-y-t-h-i-n-g. My recommendation to you: if you don't want something this big and *HEAVY*, then sell it, and replace it with a good isolation transformer (of which I own five). Where is your studio located?