[brj]

If I missed these answers somewhere in this 8 page thread, my apologies!

1) From the pictures, it appears that the Ref 8 amps have ventilation holes on the upper surface.  Would stacking these amps on top of each other create enough blockage to cause heat buildup problems?

2) Does the amp enclosure have damping material already applied?

3) Does the price for the Ref 8 include a power cord of some kind?   I know that a separate "NuForce/Stealth Power Cable" is available, but it wasn't clear to me if some more basic power cord was included with the amp, to which the Stealth was a potential upgrade.

(Power cord arguments aside, I just can't make myself believe that the R&D and labor/materials costs involved in designing and producing the Stealth power cord vs. the Ref 8 amps themselves are proportional to their respective prices of $480 and $800.  Yes, I know, different market forces probably apply, but still...)

Thanks for any feedback!

[nuforce]

1) From the pictures, it appears that the Ref 8 amps have ventilation holes on the upper surface.  Would stacking these amps on top of each other create enough blockage to cause heat buildup problems?

Stacking them for normal use is perfectly fine, make sure there will be air circulation.  An extreme case such as running the amps 100W all day, at 70% efficiency (85% SMPS x 80% Amp), you'll be dissipating 30W of heat, and typically, the temperature goes up about 1-degree-C/W.   That's like 30-degree-C over ambient (room temperature). The 30-degree-C of extra heat will compound the other amp and then the ambient temperature will go up in proportion.  Just make sure that the air aorund the 2 amps is circulated.

On the other hand, playing music at normal listening level, you'll be running it at 10-15W, we are then talking about 5-W of heat, nothing to be worried about.

2) Does the amp enclosure have damping material already applied?

Even though we have real science, we also pay attention to get the amp sounding right.  Damping material may distract rather than improve Ref8.  If you're really into improving the last bit of performance, put them on some energy dissipating shelf/feet, such as carbon graphite blocks, Aurios, cones. [/quote]

3) Does the price for the Ref 8 include a power cord of some kind?   I know that a separate "NuForce/Stealth Power Cable" is available, but it wasn't clear to me ...

We do include and provide power cords for USA customers.  International distributors can provide the correct cords suitable for each countries' AC system.

[WerTicus]

The system I heard the demo pair on was WAR audio's reference one speakers... which are in the photo on nuforces website... you can see the raven tweeter, cabasse woofer and ceramic accuton mid.  45litres, 89db rear ported base reflex good from 35 to 100khz.

with all the rest of the system as listed.

At home I have a raven tweeter in an mtm with some vifa 6.5"s  cant believe the bass I am getting out of these things!

next week my reference ones should be finished - speakers of this level cost 40k+ in the usa and europe here Pat sells them for 8k.  They have been compared to and come out on top of many big names, that are costing even more than that.  I have personally put them up against the linkwitz Orions and they were not even close.

As far as heat is concerned: I have run the nuforce 8's at 'just below' clipping level for hours on end, they get 'a little warm' maybe 50 degrees and I have them stacked also!

Came with no power cord - i wonder if such an efficient power using amp would benifit all that much.  But intend on testing

[Hantra]

Came with no power cord - i wonder if such an efficient power using amp would benifit all that much. But intend on testing ...

Hahaha!!!  Yep. . . it's SO efficient it just pulls power from the air.  

[brj]

Thank you for the response!

2) Does the amp enclosure have damping material already applied?

Even though we have real science, we also pay attention to get the amp sounding right. Damping material may distract rather than improve Ref8.

I may be mis-interpreting your comment, but your statement that "even though we have real science" seems to imply that you don't believe resonance control to be of scientifically proven importance, but rather an unvalidated "tweak".  My understanding is that capacitors, at least, may be subject to vibration induced microphonic resonance.  Indeed, even the NuForce website states that the "chassis is completely made of high grade brush and anodized aluminum to reduce audio resonance."

By no means do I believe that we are talking about a first order effect here, and I certainly don't mean to imply that there is some lack in an amp design I have yet to hear (but would like to).  I simply found your statement interesting, and hoped for some clarification.  Additional comments would be welcome, as well as any elaboration on whether damping material "may," or may not, "improve [the] Ref8"?

Thank you!

[nuforce]

My colleague might have gotten us into a topic (damping material on the case) that we don't know how to address. So we should not attempt. We haven't done any study, whether it is listening test or some scientific measurement for that matter. If we don't have anything to say, better shut up then trying to bullshit or pretend that we know better than someone else out there.

Jason

[WerTicus]

i have always found dampning to help.

with any application - these amps still sound better with nothing to dampen them - i have them right in the line of fire of the speakers too at the moment.

[nuforce]

This is a self oscillating and switching amp.  They are inherantly 'violent', with the 4 MOSFETs switching at 500,000 times/second.   However, the front end buffer still need to do -100dB to have THD<0.0x%.

[Parnelli777]

Can you recommend a preamp that will work nicely with these for under $1000.00?

[WerTicus]

I had a look inside the box and i thought the speaker terminal 'wire' was interesting... any science behind these silver ribbons? they sure look cool

[nuforce]

The silver wire sounded the best. We can't give away all our secret source . Even the power wire is special.

We'll introduce a preamp later this year. We can't find any sub $2000 preamp that can match the performance of our amp. We think this new preamp should compete well with anything within 3X its price range. Will like to hear what others have to say. It is our mission to bring super high end audio performance to premium consumer price. To fulfill our mission, we might have to keep expanding our product line .

[topster]

Given that the ref8 is a switching amp, would it be sending hash back into the power supply?

I read that was the reason why linear power supplies are preferred for audio applications.


Thanks.

[audiojerry]

Ths is a short update on the status of my audition of the Nuforce, which arrived on Thursday.

The amps are still breaking in and are changing dramatically. Unfortunately, I lost 36 hours of burn-in time when my transport stopped playing after one cycle instead of continuously playing on the repeat cycle while I was gone. arrgh!

As a result, they have about 30 hours of total burn-in. I'm not ready to pass judgement, but at this point I'd have to say that the Nuforce deserves serious consideration by anyone paying attention to this thread.

I'm still trying to get a handle on its sonic signature, but I'm impressed by a number of attributes. That alone says alot when you consider that my reference is a 10k Audio Research tube amp. It has no trouble driving my Dynaudio Special 25's or Dali Euphonia MS4's.

I'd like to get some second opinions from fellow AC members living in the area like Earlmarc and Spectralman, who both own the EAD Carver, which also has impressed me.
Or anyone else who'd like to come and check this Nuforce out.

If Nuforce is reading this, can you let me know when you want me to ship this back, or if you want me to ship it to the next person on the audition list? I hope I have until next weekend at least.

[nuforce]

I am glad Jerry likes it.  Sure, keep it a little longer if you like.
Keep in mind that Jerry is auditioning the 70W version.  The 100W amp has a lot more continuous power. Both amp has the same 288W peak and 144W average cycle power into 8 ohm. In response to the previous posting, it is not true that switching amp can't out perform linear or tube amp.  Our amp is unlike other switching amp. Read the technology and FAQ sections on our website.  Reviews after reviews have confirmed that NuForce amp can stand up to amp costing well into the 5 figure price range. We decided to shorten the audition queue by sending out more amplifiers so stay tune. But supply is extremely tight.

We're not trying to start a price war with other manufacturers, just in case there is a misunderstanding of our mission. We believe that with breakthrough in technology and high volume manufacturing technique, we can bring high end audio to average consumer and thus expand the market for all vendors.  If prices continue to stay high, we won't be able to bridge the gap and reach the new generation of music lovers who grow up with ipod/mp3.

Jason

[guest1632]

I am glad Jerry likes it.  Sure, keep it a little longer if you like.
Keep in mind that Jerry is auditioning the 70W version.  The 100W amp has a lot more continuous power. Both amp has the same 288W peak and 144W average cycle power into 8 ohm. In response to the previous posting, it is not true that switching amp can't out perform linear or tube amp.  Our amp is unlike other switching amp. Read the technology and FAQ sections on our website.  Reviews after reviews have confirmed that NuForce amp can stan ...

Hi Jason, You are talking about getting prices down to the average consumer. Do you really think that a typical consumer will pay $800 for an amp, each mono block, single channel?I do not think so. I most likely will when I have the cash do do so. This was why I suggested taking your 70W and putting them in a stereo configuration.  Are you guys planning to have an intregrated? Actually, a price war would be a good idea from the standpoint, that there are a lot of high priced stuff out there that is high priced in some respects for ego, and well, because they can. I don't want to mortgage a house, just want to have a stereo that will last for awhile and sound really really good.

Ray Bronk

[Occam]

....Keep in mind that Jerry is auditioning the 70W version.  The 100W amp has a lot more continuous power. Both amp has the same 288W peak and 144W average cycle power into 8 ohm....

has a lot more continuous power? 30watts or 1.55dBW What am I missing?

[Agisthos]

I like Ray's idea of having a stereo version.

But I think $800 per mono block is very reasonable if it really is a giant slayer.

When you consider that there are amps that cost 5k and sound rubbish then you are most definately starting a price war against the high end country club. But it will be a just war  

[dr_minky]

(Sorry if this has been covered before, I'm a newbie to the circle)

What is this amp's clipping behaviour like?  When it does finally clip, does it soft clip like the icepower/tube amps do or clip nastily in Tripath/AB style?

As far as preamps go, is a simple passive attenuator likely to cause impedance problems, or is a buffered output recommended?  cheers.

[WerTicus]

its a wierd clipping - definatly a soft clip and its able to play a lot louder after break in i noticed

[Agisthos]

I realise this is a nuforce thread but ..... Werticus and Rocket what can you tell me about these War Audio speakers? Their website tells you next to nothing and the kit page only shows a page with some pictures of, I have to say, damm ugly speakers.

Of course looks dont matter sound does. I live in Adelaide and we have VAF Research, Krix, Sonique, Duntech so there is a whole lot to choose from as far as speakers go.