Nuforce STA200

I know this is an old thread and I am a new member, but I have a question about the STA200 for which I cannot for the life of me find an answer.  Is it stable driving a capacitive load?  I have Vandersteen 2ce Sigs that I want to vertically biamp with a pair of STA200s.  However, Mr. Vandersteen warns that many solid state amps are unstable driving the capacitive load when vertically biamping.  I tried calling Optoma to ask, but their tech support is dedicated to their projectors, not their audio stuff.  Please help?!

Hi Mr.D.  I was hoping to hear from you.  Your comments about this amp are largely why I decided to buy a pair.  Apparently, RV used to recommend vertical biamping in his manuals, mine included.  He now recommends against it on his website and his newer manuals.  Here is a quote from RV himself on the “Ask Richard” section of his website:

”VERTICAL BI-AMPLIFING IS NOT RECOMMENDED AS MANY AMPS OSCILLATE WHEN NOT HAVING A GROUND RETURN DRIVING THE TOP END OF THE SPEAKER. THIS PART OF THE CROSS-OVER IS CAP COUPLED FOR BOTH THE MID-RANGE AND TWEETER THIS COULD CAUSE THE AMP TO OSCILLATE AT VERY HIGH FREQUENCIES. THIS COULD BE A PROBLEM AND DAMAGE THE TWEETER.”

This has me scared to try.  I wonder if this phenomenon is unique to his first order crossovers.  I have had my 2ce Sigs vertically biamped with Rotel for the past 13-14 years.  But I’m still scared of damaging something if I do the same with the STA200 I just ordered.  Thanks!

Thanks JL35 and Mr.D.  I think I’ll see if RV knows about the NF amp.  I might even ask, in a diplomatic way, whether his retraction was an overreaction to a minute number of incidents.  Thanks again!

I wanted to report back that I have now tried a pair of the STA200s vertically bi-amping my Vandersteen’s.  No oscillating!  Phew!  The amps sound great, but they’re still breaking in.

RV said to listen for extra brightness when bi-amped.  I had time, so I compared and found no additional brightness.  I didn’t want to go through the hassle of returning one of them.  I really like the sound staging and imaging from the amps.  Bass seems a little lean, but it’s fast and articulate.  Hopefully the amps will bloom a little more after breaking in.  I’m using a brand new Parasound P7 all analog preamp with it, so maybe that needs some break in time too.  New power cords too.  I’m incredibly impressed with how dead quiet the amps are, however.