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? 

What Pre amp are you using? You could always hook up a DVD or CD payer directly (do not play 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.
Checking in. Japol, how are things going ? Hello to everyone else. Enjoy  MrD.
Hi Mr. D,

I apologize for not getting back to y'all earlier. I got caught up with some other stuff and just decided to order a Schiit SYS to see if that fixed the problem.

I was using a cheap FX Audio Tube pre-amp/buffer with the upgraded GE tubes. The tubes definitely produced a significant amount of noise once the volume knob hits the 9 o'clock mark, and the noise only increases from there on. I received my SYS yesterday and tried it out last night. With my chromecast audio and NEC cd player connected on the SYS, the noise on the speakers was cut down in maybe half. There is still a very faint shhh noise on the left speaker when I put my ear right next to the drivers, while the right speaker has a faint high pitched noise on top of the shhh noise. I'm only a beginner in audio stuff, so I would assume this would be what you call the noise floor of the amp, right? Now with the SYS, music is more detailed and has a very slightly wider soundstage compared to the FX Audio tube preamp. I tried connecting the chromecast audio to the FX Audio then routed the sound to the SYS before going into the amp, and the sound warmed up a tiny bit with a very minimal sacrifice in soundstage. So, based on the different combinations that I've done so far, the noise that I'm hearing is coming from, or caused by, the amp itself.

Last week, before ordering the SYS, I tried the amp plus FX Audio tube preamp on my daily system with NHT speakers. There was still that shhh noise and a slight high pitched noise (I don't exactly know the frequency of the noises). Although the noises that I'm hearing on my NHT's with the amp are similar to the noises that I'm hearing from my Pioneer stereo receivers and vintage integrated amps. I guess the noise floor is normal with such a high gain amp. Kindly correct me if I'm wrong.

Based on last night's listening session, I am happy with the amp. I will give it another go tonight to see if my thoughts change. Before getting this NuForce amp I had a Linn LK140 that I bought used, but decided to return it to seller because one channel was buzzing and when I opened it up there were signs of damage, repair, and a missing capacitor. That amp was quiet though, aside from the buzzing on one channel. My other amp option is to get another used Linn amp and hope I'd get lucky with a good example.

Thanks for your help, Mr. D, and to everyone on this forum! I really appreciate it.
Hi Japol, I hope Mr. D posts here quick to help you out as I don’t have enough experience with gain issues, so these are just random thoughts until the voice of experience chimes in. My first thought would be that to determine if you have a gain issue you should just hook up the Sys with the amp, and the amp to your speakers and with no sources connected see if there is a "hiss" caused by too much gain or the if there is still the "high pitched noise". If not, I would think, but may be corrected, that the noise issue is being generated by your sources, wiring or a ground loop.

If you determine that in fact these noises are the result of the amp I would not think twice of exchanging it for another one or if you choose a refund. If it was a noise floor thing I would think the "hiss" would be the same level from both speakers, and no matter what there should be no "high pitched noise". But again, wait for Mr. D.