Nuforce STA200

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,.

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. 

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.

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. 

OK

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

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

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.

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.  

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!

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.

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.

I guess adding to the above, and I have not looked into it at all, I get the impression that the STA200 is the only non class D amp they make?

Same circuit board:


https://www.audiocircle.com/index.php?topic=151000.0

I am not concerned one way or the other, but based on the above and the link, do you believe that the Nuforce and Job are more or less similar amplifiers?

It is well documented that the STA200 is a scaled down version of the Job 225, which is based on a Goldmund reference design.

Yes, but at what point does having, as you mentioned above, different caps, resistors, power transformers and RCA jacks override the similarity in sound from having similar circuits?

Not a concern one way or the other to me, I like the amp.

sound is extremely similar...at the original list price, most found the Job a much better value, both for the extra power and the Goldmund name...so fortunately for us, the Nuforce was continued at this outrageously low price...

and the Job is a much easier preamp and speaker
 match...

Thanks, jl352.  Incidentally, I was lucky to not have the preamp/speaker mismatch. I guess the three pairs of speakers I have used the amp with were not so efficient to create any (hiss/volume control)  problems.

I did end up purchasing the simple little Schitt sys which I like experimenting with just for fun, but most of the time I have it set full volume so as to not impact my tube preamp signal going to the amp.

Base on this thread,  I just purchased this amp from Audio Advisor. A Demo unit. I also have a Schiit SYS which I will try with it. Will likely pair it with a DAC/PRE in a second system later. Will get back after gaining some experience with this. Probably not work well this my Jolida Fusion preamp as it has 26dB gain. 

How does this compare with the Schiit Vidar?

If anyone thinks, or feels ( jeenam ) that the circuit boards are identical, I would like to see proof from you, or anything in writing indicating they are identical. They might be similar, but are not the same. If you look closely at photos of each ( there are many photos available on the net ), you will notice differences in the board " traces " of each. You can easily see these differences in the 2 photos provided in the link. I would like to move on from this. Merry Christmas to all. Enjoy ! MrD.

Stuff- I searched and searched for someone that has had both the Vidar and the Nuforce, never found one. There is someone on "superbestaudiofriends" who posted he had both on order over a year ago, but he never chimed back in with his thoughts/comparison.

I bought the Nuforce, so I am going to believe it is the better amp. ;)

Mesch, I am running my Nuforce with a FLAC server->Schiit Modi2 DAC->Schiit SYS pre and a pair of Wharfedale Emerald 97 MK IV spks, and I am very happy with the overall sound. 

Anyone have an issue with the power button?  When I first got it,the power button wouldn’t stay “in”. It kept popping out. I almost returned it but then it worked so I kept it.  Was fine for months then it happened again two weeks ago, and has been fine since. 

Sounds great btw. I’ve had the Job 225 twice and the Job INTegrated once. Fantastic stuff. 

Brad, Thanks for your input.  I am using my Macbook Pro with Pure Music as my server for AIFF files. Will try using it with a DAC to SYS to Nuforce. The SYS-Nuforce will replace a NAD C356BEE integrated. Also have a Pathos Model One MK2 I rotate in. Speakers are: B&W 685s or Focal 706s. Looking to upgrade speakers in 2019. This is a secondary system.

@brad1138
Stuff- I searched and searched for someone that has had both the Vidar and the Nuforce, never found one. There is someone on "superbestaudiofriends" who posted he had both on order over a year ago, but he never chimed back in with his thoughts/comparison.

I bought the Nuforce, so I am going to believe it is the better amp. ;)

And you've got 200 bucks extra in your pocket to boot.

Anyone try the WDC200 with the STA200? There's precious little info online, but if its anywhere close to the STA200, they combo could be a killer value on the electronics side.

https://www.youtube.com/watch?v=twgbZ-uWRhE

How do the three compare devilboy?

No problems with my two STA200’s

I was starting to get gung ho about buying a new amp. I’ve changed my focus, again, to focus on cables and a TT. The STA200 just sounds so right ....I can’t believe I purchased this as a stop gap a year and a half ago....and still do not want to upgrade.

Been reading about a lot of dacs, trying to figure out what might best match this amp.  NuForce has the Dac-9, there’s the Metrum Acoustics Amethyst, and I very tempted to go tube rolling with the Jolida Tube fx Mk3.  I listen exclusively thru Tidal via laptop and rarely use headphones.  Would like to know what other STA-200 owners are using.

Don't bother with the Jolida Tube fx Mk3. I had one and it isn't a good value. I'm running a NAD M51 and am very happy with it for the price I paid ($650 used). Chord Mojo are a great value at current used prices.

@jl35 I can’t really comment on how the three compare because I changed my system around so much. However, both times I had the Job 225 and the one time for the INTegrated they were all very dynamic, fast, open and clean sounding with very nice bass control and surprisingly "warmish" mids. I’ve had all of them on three different Metrum DACs.

Funny thing though... One of my best systems was a Metrum Hex, Tortuga LDR passive and the Job 225. That said, I inserted the INTegrated in there and missed nothing. I then sold the Hex, Tortuga and 225. I just couldn’t justify the price difference.

I also had the Lightspeed Attenuator in there with great results.

Be aware using tube preamps with the Job though. No DC protection so if any gets passed on from a tube amp the 225 will pass it on to your speakers. So for those of you using a tube preamp with your STA 200, this is something to be mindful of.

Thanks for the heads-up Devilboy! I have a Jolida Fusion preamp. Likely too much gaib for the 200. Won't even try it now. Have other use for the amp. Thonking of using it with a DAC/Pre of passive, currently a Schiit SYS but considering the Lightspeed. 

Laughing at my last post. Don't know what gaib is, and don't know how to Thonk. Any help?

Too much gaib is never good, and I always try to not Thonk too hard...  ;)

Pro-Ject Prebox s2 (using only as a DAC..not preamp)

I thought about the Pro-ject Prebox, but this where it gets a little complicated.....I’ve had this system together only 1 year, started from ground zero, and now I have upgrade-itis.  Deciding what to upgrade next is tough.  With the STA-200 as the mainstay of the system, I think maybe the CEntrance is good enough, for now.  My diy speakers are excellent, as are my diy cables.  However, I bought the basic Luminous Audio passive pre-amp, and I’m thinking the upgrade to the Walker Mod might be the biggest bang for the buck right now.

I had been considering giving this amp a shot but my interest is starting to wane after reading this

https://www.audiosciencereview.com/forum/index.php?threads/review-and-measurements-of-nuforce-sta-20...

Read the link quoted above.  I don’t pretend to understand all of the amp’s measurements, but I know from speaker building that some that measure well don’t sound particularly good, and vice versa.  My speakers have a good 5dB peak from 10 kHz to 20 kHz; they don’t measure flat.  But that steadily increasing response has a lot to do with the air and detail I hear in the treble section.  I could control for that peak, by filtering it out and up with a dull and lifeless response that measures flat. With the STA-200, I’m letting my ears be the judge, and apparently others are doing the same.

The test was done into a 4 ohm load. Rated output was measured as 76wpc. Seems to me one might consider this amp as a 40wpc at 8ohm supplier. Did I miss something?

Test or not at $499...the amp sounds terrific. 

aberyclark +1 

I tend to not put much stock in reviews when people take a fantastically reviewed piece of equipment, and say, "but look at these measurements I came up with"..... Especially when it is a lone voice.

Nine months ago purchased a pair of the STA-200’s to bi-amp Martin Logan SL3 electrostats.  Very satisfied.  After about 200 hours of break in time can verify the good results reported by others.  Liked them so much purchased a 3’rd and sent it to my son (at $499 from AA a steal).  Ditto results.  The only issue, as reported, is the high gain.  They do not distort even when pushed hard, but it limits out on my system at 11 o clock (too loud), more like 9:30 for normal listening.  I use a DB hand held meter to preserve my hearing.  The only issue is the amp does induce a slight hum from my tube phono section in neutral..  Have a Schiit passive on order and expecting it any day.  Based on reports here I’ll try an upgrade to the PC.  Thanks for the recommendations.

The STA200 doesn’t have specs provided for 4 ohm output because the transformer limits the power output, plain and simple. The same thing goes for the Job 225 which the STA200 is based on. The output into 4 ohms cannot double with either amp because the transformers cannot supply enough power, hence the 4 ohm output is nearly identical to 8 ohm output.

This can be verified by reading one of the Job 225 reviews on the net (I forget which one exactly).


Also, as others have mentioned, I listen and judge with my ears, not my eyes. You will find numerous people who bash REL subwoofers because of their poor measurements, but ask folks who actually own and use REL subwoofers and they will tell you they are the bees knees.

Just received my STA200 and am playing it via a Schiit SYS. As to my earlier post today, my only concern was about power output not sound quality. My amp is a demo unit, however I have no idea about the number of hours use it has taken. Out of the box it sounds quite nice, my impression is that at $500 it is a high value amplifier which requires careful pairing to regarding signal strength and speaker load. 

I have had no problem powering either my 6 ohm 89db or 6owhm 85db speakers, but neither are crazy loads.  Also, not sure if its because I have a tube preamp or not, but no obvious gain problems.  Maybe just lucky.

Thanks for the comments guys I am looking to power 86 dB proacs and had started to think maybe the amp wouldn’t be able to power them sufficiently. I am considering an nad m51 as a pre.