Nuforce STA200

Check pictures of the Job 225 and STA200 again. They use the same circuit board with different caps, resistors, etc. The power transformers and RCA jacks are also different.

MrD, in the small room with the Proceed (Turntable room), I never listen above about 80 dB at sitting position, usually closer to 70 dB, so it never got any kind of workout, probably running at less than 1 wpc. Running my Wharfedales downstairs in an open area of around 10,000 cubic feet, I had it running at a moderate level (my wife would say loud) filling the entire area for hours and it was lukewarm at best afterwards....

Just weird, never had an amp act that way.

When my 160w monoblocks needed repair I ordered the Nuforce from Amazon as a stopgap.  To my amazement, at half the power it ran my very inefficient speakers wonderfully, almost equaling the sound of my original amps.
When my monoblocks went down again I thought it was time to replace them permanently, so I bought used a highly touted expensive Belles Hot Rod amp.
In short, the Belles couldn’t cut it.  It just didn’t have the power of the Nuforce which sounded much better.
I can’t  believe the quality at that price.  Amazing!

I've never had it break 95 degrees on the heat sinks which by the way is about the same as the Class D amps I have owned.  The Job did not run hot either.  

Brad, does it run cool on the speakers currently being driven with the Proceed ? It is AB for sure. As a correction, if I may. The STA 200 does not use the same circuit " board " as the Job, but it does share the same circuit design. The design is exclusively Goldmund. There is a lot of fascinating information about this circuit on the web, licensing agreements, and differences between the Job and the STA 200, and much more. Enjoy ! MrD.

Based on the same circuit board as the Job 225 so not Class D. 

How does it run so cool? It is almost cold to the touch, even under load... Are we sure it is class AB?

OK

MrD, thanks, the Nuforce was dead silent in the Freya's passive mode. 

Some early production Freyas had a lot of tube noise, but if I send it back I may just get a "that's normal" response and be wasting my time... 

I have decided for now to just keep using it in passive mode. 

brad, if you were to connect the Nuforce to your speakers, without connecting anything to the amps input, ( any amp for that matter ), you may find the Nuforce / other amps to be quiet through the speakers. I have done that with both of my Nuforce amps through my 104 db efficient speakers. The Nuforce amps were silent.I believe you may have a problem with the Freya, or a tube ( s ), as others have not reported very loud hum / static / hiss etc. Enjoy ! MrD.

I also have a Freya, I could not use the Tube stage with the Nuforce, very loud hum/static/hiss etc. I actually can't use the tube stage with any amp, in my 12' x 13' x 8' room with 93 dB efficient speakers. Nuforce's high gain made it even worse than other amps I tried. 

I found I like the passive mode best anyway though. 

I have a modified Adcom GDA 700 ( an oldie ) along with an after market cord and fuse. I've tried some more recent units ( all under 1K retail ) and still enjoy mine. I have an AA DDE V3.0, with an upgraded power supply and power cord in another system, which I also enjoy. Enjoy ! MrD,.

Hi MrD-

Are you using a dac with the STA-200?  If so, which one?  I think we’re both using the same passive pre amp.  I’m using a CEntrance dac mini, but thinking of upgrading.

Thanks, MrD!


I probably won't use my system until I have the room ready. And that could be a while yet. But it sounds like this STA 200 is really a nice sounding amp, regardless of price. I have a Freya on my main system, and love the adjustability of the Schitt preamps with the passive and tube choice. Some songs on my main system sounds more transparent and detailed with the passive, even though I use the tube section of the Freya more.

The Saga and STA 200 work well together. The input gain on the amp will easily allow you to use the Saga in passive mode, which I prefer over the tube stage. It is of course personal, and you might like the added color and roundness of the tube sound. Note : It also has to do with your source's voltage output and power supply design, when using it in passive mode. Enjoy ! MrD.

I bought one of these probably about a year ago. Haven't tried it yet. I bought a Schiit Sage preamp to go with it. Has anyone tried the Saga with it? I've been wondering if the gains will match each other.

Can't help you open the case.

My purchase of the amp was necessitated when one of my monoblock amps blew out. I was looking for something that was relatively inexpensive that would hold me over until I could figure out whether I was going to purchase something in the price range of a Bryston 3BSST, Simaudio W3/W5, etc. To my surprise the damn thing sounds as good as others have commented and with my modest apartment it drives speakers as loud as my neighbors can stand.

I feel a little embarrassed to ask this question, and I will explain why. Simply, in my 50 plus years at this ( as an audio professional and consumer / hobbyist ), I have opened every amp I have every owned, to do a mod or 2 of some kind ( everything can be modded, for improved sq ). Has anyone been under the hood of the STA 200, as I have a few mods I would like to do. Removing the 4 philips screws from the rear side walls, I would think you spread the side walls, from the rear where the screws were removed, to loosen the top. I have tried, very gently, but they did not budge. I did not want to use excessive force. Nuforce has not answered my emails, as I suppose they do not want me in there. I would appreciate any response. BTW, as I have said before, this amp does so much right, musically, that although some amps might be better in 1 or 2 ways ( through a particular set of speakers, due to efficiency / impedance ), this little amp is quite the beast. I have owned AR, Krell, CJ, Threshold, Bedini, Ampzilla, you name it. Amp sounds best on a non resonant shelf, being left on continuously with signal playing through it ( a few hundred hours ), an after market power cord, and a 1-2 lb weight on the top center ( I use a thinking man statue over a padded piece of 4 in. X 4 in. piece of granite. Enjoy ! and Happy Holidays. MrD.

The amp originally retailed for $1200. I believe NuForce was discontinuing the amp (from what I was told). Nuforce manufacturing produced new batches to run out parts inventory at facility. However, the word got out and the amp has new life with more manufacturing runs. 

I'll be honest, if the sound of the amp with your speaker combination is what you like, you'll be find to find anything better even at $1200. Like I said earlier, I purchased the amp as a "go between" until more funds became available (my old amp blew). I decided to upgrade other components because I am so happy. After the NuForce, I purchased a Rogue tube RP-5, combo is amazing. 

It is a great amp, and it found a home in my 3rd system running a pair of Wharfedales Emerald 97 mk IVs, but it was beat out by the Proceed BPA2 for this system. 

A few weeks from now you might be convinced there's nothing at $500 that can compare. It is an amazing value.

OK, installed and running, just a couple hours on it...

WOW, for $500 this is incredibly good. Everything above that was said about this amp is true. 

I need time to really sit back an assess it, and I want to let it burn in a bit  before that. But initial impressions, great bass extension (much better than the Vincent SP-331 I tried, and better than my B&K reference 200.2 from my other system) unbelievably transparent, fantastic imaging. Deep sound stage.

Running with upgrade but generic 14 gauge PC currently.

:) :) :)

Thanks mrdecibel, I have seen them often, but I never knew that they were all basically the same device inside the cover, performing the same function. Live and learn.

Jetter, I believe you are speaking of the magnet ( ferrite choke ). Look up " what are the bumps at the end of computer cables ", as you will get your answer. These are sold everywhere, and have been for ages, in different sizes, by many manufacturers. Enjoy! MrD.

mrdecibel, what is the item that is on the stock STA200 power cord just below where the cord attaches to the amp?  I assume it doesn't impact ones choice of power cord? Thanks

Have one on order from Signal Cable. Reviewed very well for under $100 PC. 

I also picked up a Proceed BPA2 (on its way) I really miss the ML and I am hoping it will be a somewhat close match. Between the 2 amps, I am sure I will be happy :)

The amp takes well to an upgraded power cord. Enjoy ! MrD.

Those are certainly some nice speakers, if it was "good enough" for those, I will probably be happy :)

I purchased the STA200 a few months ago based on feedback from users of this forum. Speakers that I've used with the amp are PMC OB1 (6 ohm, 87db) and Alta Rhea (4 ohm, 87.5 db) and the amp barely gets warm with either.

For $500 it is a ridiculous value. I love the fact it doesn't turn into a space heater and doesn't take up a ton of space. At the price point, there probably aren't many amps that can compete with it.

I had to sell my Mark Levinson #331 a few days ago (I needed the cash...) To "replace" it, I bought a like new Vincent SP-331 off CL for $600 and this, I am going to sell whichever one I like less. 

I have been running the Vincent since yesterday, it is nice, but I am really missing my ML  :(  

If the NuForce is as good as you say, hopefully it will be closer to the ML...

If neither do it for me, I may sell them both and look at the new Class A amp from Schiit when it comes out. 

I am running a pair of Tekton Lore-S speakers and have a Schiit Freya pre.

A purchaser of this amp, from early in 2017, stated " Conrad Johnson meets Krell ". I have owned a few CJ amps ( 2 tube, 2 ss ), and a few Krells ( but am familiar with many Krell amps ), and I have to say, this amp definitely has many " high end " characteristics. What I like about it, particularly, is how " tuneful " it is. With a better pc, it truly follows the bass and rhythm of whatever music I am listening to, and I cannot say many of my amps ( and believe me, there have been 100s ) have done so well in this area. The transients are fast, and the dynamics are incredible ( keep in mind my Lascala’s are quite dynamic ). The tone mimics the music, and the spatial presentation is high, wide and deep. A killer at $499., and of course, with the right loudspeakers. It is a very musical and enjoyable amplifier. Enjoy ! MrD.

Oh well, still happy to get one. 

this morning they have new ones for $499

I just bought one from Audio Advisor, and shortly after, the listing changed to "Demo" model for $400. Looks like I might have got their last "non demo" one. :)

Anyone have any thoughts on how this would compare to a Schiit Vidar?

Thanks

kbuzz, this may be too late, but I saw your post about using a tube preamp. I bought the STA200 and had an old Audible Illusions tube preamp and there was a lot of noise. I bought a Rogue RP1 preamp which I picked partly because it has a low gain of 7 db, and that combination worked well.

+1 about imaging from the speakers (including the Xovers). If you might be looking to try to go as "dual mono" as possible for the best theoretical stereo separation with a pair of stereo amps then biamping vertically would be the way to go.. do that first but really best if you try it both ways as recommended by jackd.

The only possible disadvantage is that any variations in gain (unlikely) between the 2 amps will make one side slightly louder and may skew the soundstage when you vertically biamp.

It doesn't make any difference as your perception of "imaging" is coming from the speakers.  If it makes you feel better then try it both vertical and horizontal and see if you hear any difference.  If you speakers don't need the extra muscle then don't bother.

Maybe I’m overthinking this-  if one amp’s R and L channel play thru one speaker, and the other amp does the same thing thru the other speaker, do you get the same stereo separation as if you were using one amp?

?

Thanks MrD.  With vertical bi-amping, what happens (if anything) to stereo imaging if both R and L channels are powering the drivers in one speaker?

The STA 200 is not bridgeable, meaning you cannot combine both channels to make a single higher wattage amp ( usually impedance capability changes with the amp when you do this ). However, when you separate the crossover of the speaker, as you suggest, you can either horizontally biamp ( passively ), or vertically biamp ( again passively ), with 2 amps. Your example would be horizonal passive biamping. Each of 1 amps channels running the woofers, the other amps channels running the rest. Vertical ( which I prefer, based on my own listening ), would be each amplifier " dedicated " to 1 speaker, 1 channel to woofer, 1 channel to rest of speaker. This all works well when both stereo amps are the same. I hope this helps. Enjoy ! MrD.

Sort of a newbie question:  I’m thinking of buying a second STA-200 in case I decide to add a second system to my house. In the meantime, is there a way to use both amps as monoblocks?  I could rebuild the x-overs on my diy speakers to biwire and run one amp for tweeters and another for woofers, but I’m not sure how I might run one amp per channel.

I had a relatively high end tube preamp, which resulted in a hum through my 104 db efficient speakers, with this amp. The combo was fine with less efficient speakers. Same occurrence with a ss preamp, in both cases. Because of it’s high gain, it is a possibility noise can be a problem. The noise is not from the amp, as it is dead quiet. The other thing would be a very small amount of adjustment via the pre’s volume control. I love the amp though, and went passive. Some folks added a volume control ( a simple passive unit, something you said you did not want to do ) between their pre and the amp, to cut back the gain, and are quite happy. Enjoy ! MrD.

Anyone have any thoughts on using this amp with a tube pre amp. I have a few tube pres that id like to try with it, but really dont want to insert a passive/attenuation in between...

concerned it will generate a lot of noise..particularity if i use one of my vintage tube pres...thanks for any info

Well, I just ordered another from Audio Advisor, as, I do not know how long these will be available. I wish I was excellent with words, because I would give this amp a tremendously positive review. It really possesses all of the great attributes of so many amplifiers I have owned, and have listened to, in all of my years. Is it perfect ? Are my ears perfect, or my speakers, or my room, or my sources, or my recordings ? No, But, it is just so musical and embracing, and allows me to enjoy all of my music. And, for the money ? Enjoy ! MrD.

As much as I like the Nuforce, I would not look for a speaker it can drive. I would pick the speaker, and find the suitable amp to drive it. This has always been my approach. Enjoy ! MrD.

Well if you give the Nuforce the room it needs to breath hopefully it will hang in.  If you really like the Nuforce you might want to start looking for a more compatible speaker though. 

The Elacs really sound better with this amp than the Monitor Audios. The Monitors are really bright, almost harsh and grainy. Had to swap them back out.