McCormack DNA 0.5 vs. Parasound HCA 2003

Are your Vandersteen 3A Sigs brand new? If so, you should let them burn-in for a hundred hours or so. If not, have you tried adjusting the treble control on the back or adjusted the tilt? Instructions on the proper tilt can be found in the user's manual.

My McCormack DNA-0.5 drives the Vandersteen 2ce sig II's just fine, but I've never heard it with the 3A Sigs. Do they also sound bright at lower listening volumes?

My DNA-0.5 drove my 3A Sigs much louder than I cared to listen and I never thought of them as bright. Is the brightness the only reason you think the amp may be running out of steam? In addition to the treble control and tilt that Jebe1 mentioned, toe-in can also be important. I ran mine with no toe-in.

Thank you for your responses. The Vandy's were store demo models and I've owned them for 6 months so they should be broken in. I've turned the treble adjustment all of the way down and it makes no difference. They do not sound bright at low or moderate listening levels. Yes, the brightness is the only reason I think the amp may not have enough power, perhaps a goofy assumption but my audio dealer suggested that. I'll adjust the tilt and fire them straight ahead instead of the toe in I have now. I'm going to demo the Parasound but I believe McCormack amps are probably superior.
Sounds like you gentlemen would concur with that.