Nuforce STA200


I am curious about the Nuforce STA200 amplifier  If anyone has experience with the amp it would be appreciated if you would share your listening impressions, both good and bad.  Some of the descriptions I have read classify it as a class AB amp and others a class D amp.  I am not technical savvy about these things, can a single amplifier be both? 
Thanks
George
jetter
With either of my STA 200s connected to my Lascalas, at 104 db efficiency ( no input connected to amps ), they are dead quiet, as I hear no hiss or hum ( of course, the amps are on ). I did have issues with hum through a few preamps I owned ( own ), and now own a top model Luminous Axiom Walker unit, without problems. Unless the amp is defective in some way, I believe it is simply amplifying any  noise preceding it. Enjoy ! MrD. At this time I am using the amp pair to vertically biamp ( passively ) Signet SL 280ex speakers I have set up in another room, and the system is excellent, without any hiss or hum, using a DoukAudio passive preamp, hifi version, which I have found to be cleaner than the Schiit sys ( $40. or so from the Bay ). Currently rotating amps for the purpose of selling many of them. Enjoy ! MrD.
Hi Mr. D,

My amp, without any input connected, produces somewhat of a white noise (shhh sound). Is this normal or do I have a defective amp? I will try connecting my amp to a set of floorstander NHT’s at 8 ohm tonight.

Thanks!
Hi japol, waiting for Mr. D to chime in.  

But when you mention having a noise without any input connected.  Do you mean the noise is coming from the amp when there is no preamp or speakers connected?  If that is the case I would think it is defective and send it back and ask for a replacement.  But again, definitely wait for Mr. D.
Japol316

What Pre amp are you using? You could always hook up a DVD or CD payer directly (do not play anything...it could damage speakers) and see if the hiss is there. I had a hiss issue but it was due to my RP-5 tube pre output. I solved with a Schitt pasive pre between the rp-5 and my STA200. The amp was dead quiet with 2 different solid state preamps
Hi again all. Japol, if this shhhh sound is audible from your listening chair, again without anything connected to the amp’s input, through your speakers, I would not worry about it, although I understand the concern. Some of my other amps, specifically high wattage amps ( 200 + wpc ), do have a hiss, but not audible from my listening seat, under the same conditions. My experience with, not only high gain audio equipment, but " wide bandwidth " equipment ( Spectral as a good example ) might be prone to spurious noises from things such as digital gear, certain lights / switches, some kitchen appliances ( refrigerators and microwaves ) and even dirty electrical and nearby wires, might create this shhhh you are hearing. Do you have another amp you can try this with ( other than the STA200 ) ? Are you using the supplied power cord with the STA ? Try plugging the amp into another outlet, even if it means using a power strip, or extension cord, and see ( hear, lol ) if the Shhhh gets lower. Your speaker cable can also be acting as an antenna. Keep the speaker cables away from any electrical cables, and if you cannot, do not run them parallel with one another, if possible. Don’t give up, we are all here to help. Enjoy ! MrD.