Does Anyone have any experience with Nuforce Amps?

Kevin P · « **Reply #440 on:** 29 Jul 2005, 04:55 pm »

Hmmm... back EMF is by definition out of phase with the original signal. Its the result of the original signal pushing the coil through the magnetic field and the resulting flow of current is opposite the original. How could it be in phase?

Oh... I see. Your talking about multiple drivers. The back EMF is probably only an issue as woofers as you say.

The best way to reduce back EMF is to have a smaller coil. I'll beat my own drum here.... it's one of the advantages of our XBL^2 motors. The coil and inductance is MUCH smaller which decreases the back EMF effects.

If you want some reading to make your head hurt.

http://www.klippel.de/download/bin/AN11%20-%20Flux%20modulation.pdf

Overall speaker impedance is not that complex though and the only way you get more current without changing voltage is by lower impedance. Period.

mmakshak · « **Reply #441 on:** 30 Jul 2005, 05:47 pm »

I just got my updated amp back yesterday. Right at first it sounded closed in. That changed. I think it challenged me to come clean(based on my feeling that policies that benefit just the few are doomed to failure-my moniker). I'm preaching to the converted here, probably. First off, get a Rega Planar 3 or 2(depending on finances). This has a state of the art arm. Get albums produced before 1983(pre-digital, with a few exceptions). Get a Nuforce 8. This will change the brain waves, which is why we listen to music. I don't own the Rega, but most people don't know how to set up a turntable. The arm, I believe is not height-adjustable, hence no 180-gram records. I should mention that 8.01 is incredible(beyond my capacities to describe).

Mad DOg · « **Reply #442 on:** 30 Jul 2005, 08:30 pm »

after getting my updated ref 8s back from NuForce for weeks now, i finally had a few moments to hook them up...been out of town for the last 4 wks...

i hooked them up to a pair of Omega Mini Me speakers...WOW!!! sound is so liquid and effortless. very natural, fast, and transparent. the Ref 8s make the Mini Me really sing!

can't wait to hook them up to the Hyperion 938 and Von Schweikert VR-4Jrs...

csc · « **Reply #443 on:** 31 Jul 2005, 06:01 am »

I have been listening to a pair of Ref 8b's for the last couple of days, loaned to me by someone that wanted to hear them used with my speakers(I am now hoping he forgets

).

Even in my modest system, I am impressed with the transparency and control that the Ref 8's exhibit. Very nice!

Mad DOg · « **Reply #444 on:** 31 Jul 2005, 09:20 am »

Quote from: csc

I have been listening to a pair of Ref 8b's for the last couple of days, loaned to me by someone that wanted to hear them used with my speakers(I am now hoping he forgets ).

Even in my modest system, I am impressed with the transparency and control that the Ref 8's exhibit. Very nice!

get a pair of Endler attenuators for ~$160 and you'll be able to hear what the Nuforce amps can really do...i think you'll be surprised to hear how much your P-965 colors the sound...

lonewolfny42 · « **Reply #445 on:** 31 Jul 2005, 09:29 am »

Quote from: Mad DOg

Quote from: csc
I have been listening to a pair of Ref 8b's for the last couple of days, loaned to me by someone that wanted to hear them used with my speakers(I am now hoping he forgets ).

Even in my modest system, I am impressed with the transparency and control that the Ref 8's exhibit. Very nice!

get a pair of Endler attenuators for ~$160 and you'll be able to hear what the Nuforce amps can really do...i think you'll be surprised to hear how much your P-965 colors the sound...

Or...you can try the Ref. 8's with a cdp that has a volume control. That's what I'm doing now...amps, cdp, speakers...nice easy system. Enjoy !!

silversurfer · « **Reply #446 on:** 31 Jul 2005, 10:10 am »

Jason,

I would like to know the DC offset of your amplifiers as I'm thinking of using them in an active setup on Apogees (ribbon loudspeakers). Just want to know if I would have to place a capacitor before the MRT panel as ribbons hate DC as they are permanently magnetised at a low level, and under such conditions will drift to the limit of their mechanical resistance.

csc · « **Reply #447 on:** 31 Jul 2005, 05:00 pm »

Thanks for the tip Fo. The P-965 will probably go away within the year, and the Ref 8's will go back to their owner next week, so I won't have the chance to mess around.

That said, I am really enjoying the amps, to the point where I am almost trying to justify buying a pair or seven.

Quote from: Mad DOg

Quote from: csc
I have been listening to a pair of Ref 8b's for the last couple of days, loaned to me by someone that wanted to hear them used with my speakers(I am now hoping he forgets ).

Even in my modest system, I am impressed with the transparency and control that the Ref 8's exhibit. Very nice!

get a pair of Endler attenuators for ~$160 and you'll be able to hear what the Nuforce amps can really do...i think you'll be surprised to hear how much your P-965 colors the sound...

nuforce · « **Reply #448 on:** 31 Jul 2005, 07:15 pm »

Quote

I would like to know the DC offset of your amplifiers as I'm thinking of using them in an active setup on Apogees (ribbon loudspeakers).

DC offset is half of the supply voltage, ie 24V.

csc and others: if you're buying 7 units for HT, contact us or your dealer for special deals (warranty voided if you break them up and resell it)

.

Russell Dawkins · « **Reply #449 on:** 31 Jul 2005, 07:43 pm »

excuse my ignorance, but isn't that a huge offset and what implications does that have for any drivers that don't have a high pass filter? Does that mean the bass driver will be pushed in or out almost to the limits of excursion whenever the amp is powered up?
Russell

nuforce · « **Reply #450 on:** 31 Jul 2005, 07:52 pm »

DC offset is between +ve and gnd or -ve and gnd of the speaker terminals. Icepower has the same behavior.
The DC between +ve and -ve is less than 0.1V

Jason

Agisthos · « **Reply #451 on:** 1 Aug 2005, 02:35 am »

Quote from: Mad DOg

get a pair of Endler attenuators for ~$160 and you'll be able to hear what the Nuforce amps can really do...i think you'll be surprised to hear how much your P-965 colors the sound...

Hey Mad Dog dont you have an Aesthetix Callisto pre? How do these Endler Attenuators compare to that with the Nuforce?

Mad DOg · « **Reply #452 on:** 1 Aug 2005, 03:33 am »

Quote from: Agisthos

Quote from: Mad DOg

get a pair of Endler attenuators for ~$160 and you'll be able to hear what the Nuforce amps can really do...i think you'll be surprised to hear how much your P-965 colors the sound...

Hey Mad Dog dont you have an Aesthetix Callisto pre? How do these Endler Attenuators compare to that with the Nuforce?

hello Agisthos,

you are correct. i am running the Aesthetix Callisto Signature...the Endlers are quite good, but can't compare in terms of drive, dynamics, slam, and soundstage separation.

csc · « **Reply #453 on:** 1 Aug 2005, 04:59 am »

Quote from: nuforce

csc and others: if you're buying 7 units for HT, contact us or your dealer for special deals (warranty voided if you break them up and resell it) .

Might be giving your offices a call....

nuforce · « **Reply #454 on:** 1 Aug 2005, 08:46 am »

NuForce just received another all out endorsement from Sweden's component.se
http://www.component.se/docs.php?page=artikel-nuforce_reference8.php

We translated the conclusion:
"...We recommend warmly the Nuforce Reference 8, listen to them and be amazed and surprised. With the latest upgrade, there is no other way for us than to purchase the reviewed amplifiers. At present it is our new reference power amplifier"

Yes, NuForce has become another reviewer's reference amp.
Reference 8 reviews are in various stages of completion (some just started :O).

More reviews are coming ....

and Reference 9 reviews will begin soon.

Jason

GBB · « **Reply #455 on:** 1 Aug 2005, 11:20 am »

Quote from: nuforce

DC offset is between +ve and gnd or -ve and gnd of the speaker terminals. Icepower has the same behavior.
The DC between +ve and -ve is less than 0.1V

Jason

Hi Jason,
This DC offset has always been the one thing that bothered me about my Nuforce amps. While <0.1v probably isn't an issue, its more than seen on most other amps. Any chance the nuforce team will be coming out with a mod to bring this down to the <10mv range?

Thanks,
---Gary

silversurfer · « **Reply #456 on:** 1 Aug 2005, 02:40 pm »

Better would be to have no DC offset at all as all Cardioid or Cardioid/standard ribbon arrays will suffer from this and age prematurely or even worse..
As to ICE based amps, a solution has been found to get DC offset to zero. Maybe Nuforce can provide a mod to do this also. It would make going truly active with those amps on ribbon speakers, a viable solution.

akopperl · « **Reply #457 on:** 2 Aug 2005, 04:57 am »

What effect does the DC offset have? Will it cause any damage to speakers or result in loud pops when you power up the amp?

silversurfer · « **Reply #458 on:** 2 Aug 2005, 06:14 am »

For possible damage regarding active setup for ribbonspeakers with amplifiers which have DC offset follow these links where that subject has been debated.

http://audioworld.com/sw/Forum1/HTML/004070.html

http://audioworld.com/sw/Forum1/HTML/004216.html

With a passive setup (capacitor in place) there is absolutely no problem whatsoever.

nuforce · « **Reply #459 on:** 2 Aug 2005, 06:53 am »

Quote from: GBB

Quote from: nuforce
DC offset is between +ve and gnd or -ve and gnd of the speaker terminals. Icepower has the same behavior.
The DC between +ve and -ve is less than 0.1V

Jason

Hi Jason,
This DC offset has always been the one thing that bothered me about my Nuforce amps. While <0.1v probably isn't an issue, its more than seen on most other amps. Any chance the nuforce team will be coming out with a mod to bring this down to the <10mv range?

Thanks,
---Gary

0.1V refers to production spec. Let us know if you need to have extremely low DC offset and we will accomodate.