Nuforce STA200

What cables - RCA and speaker - are you guys using with your STA200?  I've got a mish-mash of old high-end and cheap new (Monoprice) cables connecting my DAC, preamp, SYS, amp and speakers. 

I want to upgrade, but at a reasonably low price.  

Thoughts?

Its been out a few yrs. How does the STA200 stack up to newer budget amps, Emotiva monoblocks, Nuprime, TPA3255 based etc?

mrD, your post made me laugh. Why would you want to add more weight to the SYS unit? According to the Schitt website it already weighs in at a heavy 1 lb. I’m guessing they rounded up to get there.

If anyone is interested ( and this applies to anything ), you can open up, go inside of the sys, and Dynamat the circuit board and some of the chassis, as you will hear a significant improvement in detail and resolution. It will also add some weight to the chassis. Always need to be careful when pressing down on the boards, as you do not want to break the " traces " ( Sorry, been doing these mods for 50 years, and they work well ).

The Sys is so cheap that I went ahead and bought a second to have both a dual mono setup and also to be able to control the balance.  It really widened and opened the soundstage up using two instead of one.

I've got a Saga too, but as hard as I try to prefer the Saga, I actually think the Sys sounds better.

Busy now, but agree it will be fun to use the little SYS as a standalone pre in the near future to gain that experience.  Thanks for the thought MrD.

I agree with mrdecibel, the SYS is a good way to explore the merits of using a passive. I would probably upgrade from it in my main system. 

The SYS is not the most basic as it allows two inputs.

I'm looking forward to trying. Just curious, I wonder who makes a passive pre with all the bells and whistles?

The first thing to do would connect the Sys, direct, play music of all types that you often listen to ( I do say give it about a weeks time ), and determine if you like it, better, or not. My Luminous ( $1250 ) is quite a bit " cleaner " than the Sys, but, it should still give you more of a sense of " straight wire ". Passive is not new, but sources have gotten better and beefier in the output stages. Just give it a try, be patient, and see if your ears are good with it. If you like it, then, you can shop for a unit that has what you want and need. Again, if you don't, well, now you know. Enjoy ! MrD.

No remote on the Sys.  It about as basic as you can get, but it works well.

I haven't read this whole thread, and maybe it was mentioned, but does the Sys have a remote control?  Thanks,

Looking forward to your thoughts on the SYS/STA200 direct into your Zu speakers. 

Thanks for suggestion. I will try "sys only" this weekend. Now, I did use my Prebox S2 as a pre while my RP-5 was getting repaired and it performed outstanding. Finding a passive pre with all the features, inputs and remote as the rp-5 would be quite difficult.

To both jetter and abery ( and anyone else ). Although I am not using my pair of STA 200s in my main system, I do believe it is an amazing little amplifier. I also believe I have as much, if not more, experience than most, in using the amp with several different combinations since my acquisition of the first sample almost 2 years ago. The amp was designed with a passive pre to go before it, and for a year now, this is how I have been listening. Not just with the STA 200, but with other amplifiers. Without naming names, I owned 2 top tier preamps, that were quite excellent, but ultimately, determined they were coloring, and robbing my system of details in the music. I would suggest both of you to take your preamps out of your systems, and run only through the SYS, for about a week. There will be an adjustment your ears will make, as I know you will not like everything you hear at first. But if you really appreciate your recordings for what they truly are, and can be, given time, you, like me, will stay passive. This is especially true with the input sensitivity, and gain, of the STA 200. No preamp, one less pair of interconnect, and I am telling you, your preamps are not needed. My Luminous unit is incredible. Silent, reliable, and offers me remote volume, which I never had before in my main 2 channel system. My Dac is quite amazing as well, and it is an older type ( modified Adcom GDA 700 ), and drives any of my amplifiers with ease. And if I am wrong, after about a week, all you need to do is go back to your preamps with an extra set of interconnects, and, enjoy ! So, there you have it. Enjoy ! MrD.

I finally purchased the STA 200 amp and it is only 3 hours into listening—I enjoy the soundstage, imaging and sonic bandwidth. The price is fantastic and may be a used amplifier killer up to $2000 used / $4000 new. I’m comparing it to three other amps and will post my impressions later. 
The only issue is the limited space for connecting my speaker cable for bi-wiring. 

Yes, I have enjoyed the SYS using it as a stand alone passive pre with both the STA200 and Dynaco ST-70. I have not yet tried it as an attenuator between my Jolida  Fusion tube pre and the STA200. This I will do in the future and report back. The Jolida is mated to a BEL 1001 MK5 in my main system. 

The combination of the SYS with the STA200 when paired to the right speakers makes for clean and detailed sonics. One of the best deals in audio. 

I love the SYS. I'm glad I could be of help. 

Hi deseldin, really nice that you are enjoying the STA-200, it is a fun amp, and its funny that I believe it is the only AB amp they made, the rest being class D (AFAIK).  For me, without mrdecibel's input I wouldn't have purchased this inexpensive little gem.  

The SYS is a fun little toy, the first of its sort I have had.  Have fun.

I wanted to thank you all for sharing your experiences with the STA-200. I am a new, happy owner of the amp and I would not be without the benefit of your experience.

I was a pretty serious budget-oriented audiophile once upon a time. But after decades of faithful service, I knew it was time to replace my Audible Illusions Modulus 2B. The volume pots, replaced once already, were now reliably noisy with any adjustment at all. After some research I brought home a Rogue Audio RP-1. It added a whole new layer of musical detail, but I noticed a layer of upper-midrange glare. I was prepared to look elsewhere.  

Then I realized the glare – which turned into some seriously bad distortion on a solo piano recording – was only in the left channel. I flipped the cables to my power amp and found that the distortion stayed on the left. It was not the pre-amp after all – the higher resolution of the RP-1 revealed a problem with my power amp!

So now I was faced with a larger upgrade, both the Modulus 2B and my (also ancient) Forte Audio 1A amp. Unfortunately my budget hadn’t grown! I went looking for a highly-regarded inexpensive power amp. And that lead me to the STA-200 and, ultimately, to this thread.

The discussion of the STA-200’s sensitivity, and aberyclark and jetter’s experience in solving the problem with pre-amp noise ended up being crucial. Because I had exactly that problem – when I first hooked up the RP-1 and the STA-200, the noise floor was, well, more like a noise ceiling. Tube hiss was clearly audible from my listening position and, although the music through the RP-1 and STA-200 sounded great (dynamic, rhythmic, detailed and supple) the hiss was there every time the music got quiet or silence appeared. Not only that, but any RP-1 volume setting above about 17 (60 being full gain) was too damn loud for my room.

I immediately bought a Schiit SYS, just like aberyclark and jetter. As soon as I popped it between the RP-1 and STA-200, and dialed down the gain to 12 o’clock, the hiss was gone. But not the music. I’m running the volume control at anywhere from 25 – 35 now, so I haven’t even begun to max out the RP-1’s gain. I am very, very satisfied.

So thank you for your contributions to this discussion, especially aberyclark and jetter. I greatly appreciate your help!

Okay guys, sorry for the super delayed response but I wanted to try every option I had before posting another reply to the thread. I tried switching out to different interconnects (both are cheap options but I know both of them are shielded), but the same noise is present (hiss in the tweeters and hum in the mid range driver). So I went ahead and ordered an Emotiva CMX-2, which I just received tonight. I plugged everything in and the same noise is present. About a week ago I went around the house and unplugged electronics to no avail, and we don’t have any dimmers in the house. So, I just requested for a replacement of the amp through amazon. I should be getting the replacement on the 31st. I’ll make an update once I get to plug that thing in. Thanks for everyone’s help! I really appreciate it.

Removed my last post because it was about another amplifier, rather than the STA 200. Sorry for not keeping the thread on track. Enjoy ! MrD.

With my current speakers at 89dB, it rarely ever gets even warm, and I can’t go beyond a quarter turn with my passive pre amp before it gets uncomfortably loud.  Not sure if that translates into having the headroom for a driver that’s 84dB.  I know that every 3dB increase in volume requires twice the power.  So this new driver at 84 dB could require nearly 4 times the power play at the same level.

Yes, one person who has never had a real presence on AG. I'm not saying the person is a troll, however, one must look at what is right in front of them. Even if the amp did "pop" it would not be the first time someone got a defective (assuming the cause was internal to the unit) component. Even the big boys gets returns due to defective units. My STA200 runs quite cool, however my speakers are rated at 101db. In fcat, I have had my amp on for hours upon hours playing at decent levels, no issues. 

You know, one person posted their amp had a problem, and that person never posted again when asked to.  Then an article came out that said the wattage at 8 and 4 ohms was the same and started some worry that this was a problem.  

I ran my amp for about 8 hours straight both days over the weekend.  My speakers are 85 db and nominal 6 ohms and the amp never got warm and has never been warm to the touch. At least with my amp there is no difference in temperature between on and off. 

Had my amp for about a year now, no issues, great sound.  Current speakers (diy) are 89 dB.  Looking at a new design where efficiency would be 84dB.  Be interested in hearing from anyone that’s paired this amp with lower efficiency speakers.

I have my STA200 paired with a Parasound Zpre2 and both have been left on for about a year+ virtually without being switched off, if so, then only briefly turned off then turned straight back on.
Is it scare mongering, or should I be worried about the STA200 going pop? I find the sound quality excellent. I actually bought two, the other is still in its box unopened. For the money $499 they are really nice sounding power amps. Don't know or care about the power rating, they sure do go loud when required. These findings are to my ears. 

The hiss with the Nuforce should be louder than the Sony due to higher than normal gain. Do you have a friend’s house you can take the amp to and try there? Also, light dimmers have caused noises with my systems in other homes. Even if the dimmer is not in same room. 

Hi japol, if I understand your post above you have a hum with both the nuforce and with your sony integrated.  So you are not sure if you have two amps with a problem or the problem lies elsewhere in your system.  You have already determined that your speaker wires are ok. 

I only have a couple of thoughts.  One is are you using shielded interconnects and if shielded you are sure they are functioning properly?  The other is that I have the TV cable box connected to my preamp and this resulted in a hum through my speakers.  I had to purchase a cable tv ground loop isolator which eliminated it. 

Hi Mr. D, jetter, and aberyclark, and everybody on here! So tonight I went ahead and did an experiment. I bought a grounding adapter to isolate (disconnect) the ground from the 3 prong plug from Lowe's. That did not eliminate the problem. I also tried plugging in the amp straight to the wall outlet, but still the same problem. So, I went ahead and used a different speaker wire... problem still there. Then, I tried using my Sony TA-F500es just to see if it produced similar hum/hiss... they're still present but it is more quiet compared to the nuforce. Now, I'm not sure what's wrong with my system. 

I also tried connecting my nuforce to my NHT floorstanders and the noise is present, only louder. 

All these tests were with the sys connected to the nuforce, except the test with the Sony integrated. The hum is isolated to the mid-range driver and the hiss (sounds less of a hiss and sounds more like electricity buzzing) is isolated to the tweeter. I tried recording the noises on my phone but it is difficult to be discerned from ambient noise. 

I feel like I can live with the hum and hiss/buzz, but I also wouldn't want to be keeping a defective amp. Tough call.

Thanks again, guys!

The Nuforce should be dead quiet with Just the sys. When I had my RP-5 in for warranty work, I used my Pro-Ject s2 Pre Dac as a preamp. Dead quiet. I mean dead quiet!!! My Zu's are rated at 101 db. Slight tube hiss is normal (ear against speaker) for the rp-5. The Nuforce has such high gain, along with my efficient speakers, I needed the SYS between the pre and amp to pull things back. 

Hey Jetter, Japol and all you other audio gents. Japol, if your STA is causing a hiss through your speakers, without anything connected to the amp's inputs, I would say this is not normal. Either the amp is defective, and / or, the amp, or the speaker wire, is picking up stray electrical noises from somewhere ( see my earlier post ). If you like the amp, I might suggest you contact the seller and arrange for a replacement. If the replacement does the same as the 1st, I would assume the amp does not work in your environment ( again, the sensitivity and gain situations ). Keep in mind, things such as under cabinet kitchen lights, ceiling fans with remotes, florescent bulbs, and many other things, can be picked up by amplifiers, which could be the situation. Did you try your other set of speakers ? Keep us posted. Always, and Enjoy ! MrD.

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.

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.

Checking in. Japol, how are things going ? Hello to everyone else. Enjoy  MrD.

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.

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 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.

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!

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 mesch, not to worry, you don’t come off as faulting the amp at all. The way I look at it, whatever faults it has, it doesn't owe me anything. 

Again, I want to make it clear that I am not faulting this amp for it's quality. I like this amp!  

Jl35, yes I agree with both your points, re power output and preamp use. My thing is that I buy an amp for the long haul, and using one in a way that it is not designed for (underpowered for the load presented) is not conducive toward that end.

Jetter, I have not yet used the STA200 with my all tube Jolida preamp, as that was not the intent when I bought it. The Jolida has a gain of 20dB. I expect that I would find that I am using it's volume control at very low settings with this amp. Not sure about the hiss issue. I will give this a try and get back on that.

I did not have the too high a gain preamp/amp mismatch with my tube preamp.  While we have certainly discussed this problem here and read about it, I am curious if anyone has actually experienced the gain issue and if so:

1. Did the problem create an auditory hiss? or if no hiss,
2.  Was the problem not being able to turn the volume control up high enough to adequately use the preamp's sweet spot?

Thanks in advance

Luminous Audio Axiom ii passive preamp works great with this amp.  I use one, and I think another poster here does as well.  Dead quiet even with the STA-200’s high gain.

I think it's the preamp match which is difficult...

smallish room, about 12x14...I think the amp is fine into 4 or 8 ohms, as long as it is looked at as a fairly low power amp, which is what it was designed as...many amps put out same or similar power into 4 or 8 ohms, such as McIntosh...

Jl35, that is good to know. The speakers I own are rated higher than that, however do drop below 4ohms in the bass region. Phase angle at these frequencies is benign however. In what size room is your system?

I've had no trouble with 4 ohm speakers...currently Dynaudio Focus 220 mkll...

My STA200 is also dead quiet. Have used it with two speakers of 6-8ohms, 87dB for limited hours as it is new  Might be a compatibility problem with your preamp. Does hiss get louder as you turn up volume? Usually a gain driven hiss problem becomes more a concern with highly sensitive speakers. That said, I would not choose this amp for use with a speaker having an average load of 4ohms (see discussion above).