Does Anyone have any experience with Nuforce Amps?

nuforce · « **Reply #40 on:** 10 Apr 2005, 06:33 pm »

Input impedance is 47K.
Gain is about 21db. The gain is a little lower than other amp to allow preamp to operate at its optimal and higher volume level.

doug s. · « **Reply #41 on:** 11 Apr 2005, 01:54 am »

Quote from: nuforce

The reason we're not using a preamp in our current test system is because we can't find a reasonably priced preamp that will not distort the sound. Well, we have different purpose for our system. It is used to do listening test (we do measurement at the lab too) and we find that the Apogee miniDAC is slightly better than a good preamp.
Preamp is what it is. The goal is to have as little distortion as possible. We don't know how well NuForce preamp is going to be. It is not completed yet. Price wise, we're ...

i would investigate the dodd audio or modwright preamps. (modwright has a forum here, & dodd audio posts under the commercial circle.) if i were in the market, these would be at the top of my list. as i am totally happy w/my modded-to-the-max melos music director, i am not in the market. unfortunately melos no longer makes new gear.

doug s.

WerTicus · « **Reply #42 on:** 11 Apr 2005, 07:30 am »

I have just purchased the reference 8 from the Perth, Australia dealer after listening to it for about an hr vs the best bel canto.

This amp easily floors it - should sound even better when i get my reference 1 speakers this week

Rocket · « **Reply #43 on:** 11 Apr 2005, 01:11 pm »

Hi Werticus,

Are your reference 1's white? What preamp are you using at the moment. The only negative comment i can make about the amplifier is that it is relatively low gain (21db) and i don't think it will work in my system.

It sure sounded good.

Regards

Rod

WerTicus · « **Reply #44 on:** 11 Apr 2005, 05:13 pm »

yes they are but they are not the ones you have seen sitting in war (they were for someone else)... they are the ones that will be sitting in war this week

scott_man · « **Reply #45 on:** 11 Apr 2005, 06:06 pm »

Dear all:

Any thoughts or comments about the NuForce amps vs. the CI Audio VMB-1s or D-100s or the Bolder or Red Wine Audio modified Teacs.

The NuForce sounds great... it is at a similar price point as the CI Audio gear... It is more expensive than the modified Teacs. How does the sound compare?

I would like to audition all the gear, but I don't have the time, the kit is not available, and I don't have the money... So, I need to ask my fellow AC readers for help!

At the $1000 price point, which has the best sound: the 70 wpc NuForce amps or the VMB-1s?
And, again, at the ~$1500 price point, which has the best sound: the 100 wpc NuForce amps or the D-100s?
Sub $1000 -- how close to the VMB-1s, D-100s, etc. can you get with the modified Teacs?

Or is it more a case of not "better" but different sound?

Thanks.

Scott.

WerTicus · « **Reply #46 on:** 11 Apr 2005, 06:44 pm »

to me this amp is just a whole new level of sound

http://www.nuforce.com/reviews/waraudio/waraudio-review.htm

....

get a listen!

though i havnt heard the amps your talking about.

CIAudio · « **Reply #47 on:** 11 Apr 2005, 09:51 pm »

Quote

And, again, at the ~$1500 price point, which has the best sound: the 100 wpc NuForce amps or the D-100s?

Being these are both new products, I doubt you'll find anyone who's heard both side by side. It sounds like both use a similar design in that both are self oscillating and do their sensing directly at the speaker output. It seems the main difference is that the D-100 uses a big linear power supply and the NuForce uses a switching supply.

This tells you nothing about what either one sounds like. My suggestion, get them both and send back the ones you like least.

Rocket · « **Reply #48 on:** 11 Apr 2005, 10:50 pm »

Hi,

Dusty's advise is spot on as the only know is to have a listen to it in your own system.

Don't trust what we audiophiles recommend use your own ears and remember we all like a particular sound. As an example i bought a ps audio hca - 2 after reading glowing reviews from the professional media and audiophiles. In its stock form it sounded very unappealing and i had to modify it to get it to sound decent.

Regards

Rod

nuforce · « **Reply #49 on:** 12 Apr 2005, 03:47 am »

We have not listened to the CI D-100, so the following comments are strictly technical based on our understanding. But we believe our performance is right up there beyond the modest price point. However, as with any audio purchase, listen for yourself, work with your dealer to arrange for an audition.

1) SMPS vs. linear power supply. With a total weight of 3-lb, NuForce Ref8's standby power consumption is only 6W, less than a DVD player, and it can continuously deliver 100W of current at 70% efficiency (SMPS is 85% efficient, NuForce amplifier circuit is 80% efficient). NuForce uses extremely high-grade SMPS, which provides a fully regulated output stage (as far as we know, only 'super expensive' amplifier offers regulated output stage), the SMPS is rated 300,000 hours of MTBF at full load of 100W, and can provide instantaneous 'kick' of 1000W burst. The SMPS power supply has power factor correction that aligns the phase of voltage vs. current, then it charges up to 400V before regulating it down to 48V, and this SMPS topology addresses instantaneous power demand very well.

Linear supply does not regulate the output stage but instead it uses big capacitors as filtering and reservoir). On the other hand, linear power supply could be quieter, as they do not have switching noise. It's a trade off.

2) Tripath and Ice power Class-D amplifiers are band-limited to 20Khz upper bound. NuForce has power bandwidth from 10- 100Khz, technology used in D-100 is capable of 70Khz b/w. Higher b/w means lower phase shift at listening frequencies. Lower phase typically has better imaging.

3) CI D-100 uses a half-bridge (2 MOSFET) output stage, NuForce uses a full-bridge (4 MOSFET, 2 pairs) output stage. A matter of design priorities and goal-settings. Benefits of half bridge is cost, at the expense of using a bipolar supply and adjustment for offset. Full-bridge by its nature cancels out any DC offset, and can be used with a single supply. At very low frequency and at extreme high power output, half-bridge output stage may suffer from 'pumping' effect.

Rocket · « **Reply #50 on:** 12 Apr 2005, 04:06 am »

Hi Jason,

Can the gain of the amplifier be modded to have a higher gain? 21db won't do it for me in my system as my preamp doesn't seem to be high gain.

I am also using a perpetual technologies p1a which lowers the music by 6db which is compounding the low gain from the preamp.

Regards

Rocket

WerTicus · « **Reply #51 on:** 12 Apr 2005, 04:56 am »

Quote from: nuforce

.... Lower phase typically has better imaging. ....

Oh yeah thats one feature of the amp that totally blew me away.

the other stand out characteristics of this amp:

How fast it is - drums really hit you with such a punch I thought you needed larger woofers to do this! Definatly feel the rather large peak power of this amp, but not only power but control

separation... i think due to no x over, the bass line and the treble are more separate than ever before.

and there are just layers and layers

very

REAL sounding amp ! (mines still burning in)
make sure you have the money on you when you l isten because your going to need one when you do hear it - so far its taken pat 2 days to sell 6 pairs

(thats a lot for perth)

lonewolfny42 · « **Reply #52 on:** 12 Apr 2005, 05:12 am »

WerTicus,

Quote

home made 250w rsm a channel stereo amp x2

[/list:u]

Thanks for your comments on the NuForce.[/list:u]

WerTicus · « **Reply #53 on:** 12 Apr 2005, 09:21 am »

yeah i sold that amp to a friend and now run the nuforce.

that amp was just junk though vs the really high end gear - a lot of power but not very clean, and quite slow, its been compared favourably to the aska though ehehehhehe

i have updated my profile... i have NEW EVERYTHING, including house

Rocket · « **Reply #54 on:** 12 Apr 2005, 09:51 am »

Hi Werticus,

I'm glad to hear that you like your new amplifier, apparently it takes about 50 hours of burn in.

I saw a pair of white reference 1 speaker cabinets at pat's shop a couple of weeks ago. Were those yours? Or did you build your own cabinets?

I am in two minds whether to buy the nuforce amplifier.

Firstly, i have recently bought a ps audio amplifier and have modded it. It sounds quite good in my system and i don't feel like taking another Major loss.

Secondly, the gain of the nuforce amps is only 21db and probably won't be a good match in my system. If the gain could be increased i would be interested in buying one.

I was there when the aksa was auditioned, unfortunately it was only played for 10 - 15 minutes and wasn't properly warmed up. The aksa is still a good sounding amplifier and great for diy.

What source and preamp are you using?

Regards

Rod

audiojerry · « **Reply #55 on:** 12 Apr 2005, 12:44 pm »

Quote from: nuforce

We have not listened to the CI D-100, so the following comments are strictly technical based on our understanding. But we believe our performance is right up there beyond the modest price point. However, as with any audio purchase, listen for yourself, work with your dealer to arrange for an audition.

1) SMPS vs. linear power supply. With a total weight of 3-lb, NuForce Ref8's standby power consumption is only 6W, less than a DVD player, and it can continuously deliver 100W of current at 70% efficie ...

I like the idea of Jason (Nuforce) stating his views of his product vs. comparables. AC is a great venue for this, because it encourages open exchange of ideas, and some give and take.

But, please,

this time let's keep the discussion civil, congenial, and non-personal. We know from past experience what can happen.

WerTicus · « **Reply #56 on:** 12 Apr 2005, 02:42 pm »

my speaker cabs are white also - but with mica flecks in the paint (think 'metalic' car paint' they are still being sprayed atm and will probably be in pats shop this week finished i hope! but over all they will look similar to the other white boxes you saw.

i think you should stick to your guns rod, see how these amps you just got pan out at first before jumping ship yet again - i think your a little too impulsive

Harmon · « **Reply #57 on:** 12 Apr 2005, 04:27 pm »

What will be the gain on the upcoming Nuforce 350 Watt Monos?

nuforce · « **Reply #58 on:** 12 Apr 2005, 07:23 pm »

Quote from: Rocket

Can the gain of the amplifier be modded to have a higher gain? 21db won't do it for me in my system as my preamp doesn't seem to be high gain.

The current shipping unit has a gain of 23dB, so it's 3dB less than the so called '26dB standard'. For new production, we can easily change the gain to 26dB. The next shipment to Australia will be modified to 26dB.

Using active preamp and running it 3dB louder easily compensate for the 3dB lesser gain on NuForce, and as a result, the THD+N will improve 3dB as well.

nuforce · « **Reply #59 on:** 12 Apr 2005, 07:52 pm »

We published the wrong informatoin about the gain on our website (blame the management, ie me)
Those amps that were shipped to Australia have 26 db.
A few amps that we produce this month have 23 db (not 21 as posted).
Going forward, we're going to stick to 26 db. It is a simple change.

For those of you who have already bought the amps, please submit your review (with photo will be better) to [email protected] with subject title "review". We'll give you discount for future purchase (through your dealer), or free gift (like t-shirt, accessories or whatever

).

Jason