Noise and other peculiarities of NuForce amplifiers

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KJ

Noise and other peculiarities of NuForce amplifiers
« Reply #20 on: 10 Nov 2005, 05:00 pm »
mmakshak,

Just to clarify, are you hearing the power drain noise when you turn on the amps?  The only noise I have ever heard when turning them on is a brief static blip.

-KJ

kharma

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Noise and other peculiarities of NuForce amplifiers
« Reply #21 on: 11 Nov 2005, 12:49 am »
Thank's KJ

Right now I'm using Nuforce to drive Kharma CRM3.2Fe speaker sound awesome althought I already have Tenor OTL 35W. Source using AudioAero Capitole Mk2.3 :)

rustydoglim

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Noise and other peculiarities of NuForce amplifiers
« Reply #22 on: 11 Nov 2005, 08:25 am »
Hey, when you guys post something, please specify the version number of your amp ;).

kharma

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Nuforce Ref 8B
« Reply #23 on: 11 Nov 2005, 08:47 am »

lbo

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Noise and other peculiarities of NuForce amplifiers
« Reply #24 on: 22 Nov 2005, 01:54 am »
Quote from: nuforce-jason
the amp switches at 500Khz and the system runs at 1Mhz.


that's the part that I could never understood. how could the two run at different frequency, since the feedback is part of the amp. Are there something else that are running besides the amp's self oscillating circuitry?

Quote from: nuforce-jason
When there is no load or if the preamp is off (which act as a noise receiver), the amp could overheat.


is the amp overheating or the power supply overheating? I read the 6moon review and the reviewer seemed to suggest that the smps overheated when the amp is unloaded - which actually makes a lot of sense to me. but jason you seem to be suggesting that the amp overheats when fed with no input signal? why would that happen?

rustydoglim

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Noise and other peculiarities of NuForce amplifiers
« Reply #25 on: 22 Nov 2005, 04:32 am »
There are two switching pulses in one cycle and we close the loop at every cycle.
We added overheat protection circuit to shutdown the amp if the internal temperature exceeds 85 degree C. This kind of feature is common to most high power amps.

lbo

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Noise and other peculiarities of NuForce amplifiers
« Reply #26 on: 22 Nov 2005, 12:21 pm »
thanks jason for the reply.

Quote from: nuforce-jason
There are two switching pulses in one cycle and we close the loop at every cycle.


if you close the (feedback?) loop every cycle, then the amp must be running close loop the entire time. so how can the feedback loop runs at twice the frequency of the amp?

nuforce-casey

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Noise and other peculiarities of NuForce amplifiers
« Reply #27 on: 22 Nov 2005, 11:57 pm »
With a 500khz switching frequency, there are 2 zero-crossings per each cycle., we can oversimplified things by saying that the closed-loop response is 1Mhz.

lbo

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Noise and other peculiarities of NuForce amplifiers
« Reply #28 on: 23 Nov 2005, 03:46 am »
Quote from: Casey
With a 500khz switching frequency, there are 2 zero-crossings per each cycle., we can oversimplified things by saying that the closed-loop response is 1Mhz.


why cannot we do the same and say that the amp itself runs at 1mhz?