Just Bought Norge MOSFET Reference 2000 Stereo Amplifier

[captrajesh]

The last thing I would want is to have this kind of drivel being taken verbatim by inexperienced forum members.

@aarmath, I appreciate your concern but what I guess FM 'Fantastic' is stating is, a more sensitive speaker would manifest it aurally louder than a lesser sensitive speaker at given level of the amp. To term it as 'drivel' is taking things far IMO.

If the speaker is very sensitive the hiss will sound louder on it than a less sensitive speaker under the same conditions.

 

[jls001]

True.

It's no drivel. It's just simple physics at work here.

And why the unwarranted harangue against Norge? They have a target market, and they obviously have to build to a price point, and therefore some cut corners are a given.

 

[aarmath]

@aarmath, I appreciate your concern but what I guess FM 'Fantastic' is stating is, a more sensitive speaker would manifest it aurally louder than a lesser sensitive speaker at given level of the amp. To term it as 'drivel' is taking things far IMO.

Hi Rajesh,
Please explain to me how a relatively more efficient and sensitive speaker in our times will manifest hiss aurally more than an inefficient speaker?
From what perspective?
ah... From the perspective of the amp of course and I hope you will agree with me on that. On its own a highly sensitive speaker (not withstanding subjective audio quality experience) can be driven by say a tiny Tripath amp (a great amp for its size). It is the amp's design prerogative to keep inherent hiss as low as possible in the first few watts (amplitude of the signal). It could be a 20 watt or a 200 watt. The intent is to NOT have hiss manifest in the first few notches of the volume level regardless of the speaker in use.

And yet the discussion makes it feel that the Norge amp has no inherent problems simply because it is connected to an efficient speaker. That's where the drivel part comes in. Either we can accept that there is a flaw in the reasoning or be politically correct. I choose the former so that young folks who would want to get into musical audio in the stereo domain do not get swayed with incorrect suppositions and fundamentals of basic music system setups.

True.

It's no drivel. It's just simple physics at work here.

And why the unwarranted harangue against Norge? They have a target market, and they obviously have to build to a price point, and therefore some cut corners are a given.

When did offering an honest politically incorrect opinion about a brand become an unwarranted harangue? I had a Norge amp from my school days. At best they were a poor substitute to what was then very very unaffordable foreign amp brands that were available in the mid 90s to early 2000s.
And yeah to my ears the Norge sound quality was, well to be politically correct, not upto mark.

I am curious though, what corners are cut by Norge to maintain its price pointsa nd why is it a given? Is ugly hiss from an amp in normal audio level range that too in today's time a given for the buyer?

 

[elt93]

A simple experiment I've done.
Equipment: onkyo integra p308 preamp, onkyo integra m508 power amp. Speakers sony ss g7/94db & b&w dm303/88db.
with no source connected, there is a very very faint hiss that can be heard when the ear is right next to the tweeters of the Sony speakers. However I cannot hear this hiss through the b&w. Increasing volume has no effect on the hiss (in the case of this amp). It's just there. Mind you this is with the ear right next to the tweeters.
Now go figure why. I'll agree with jls001 that it's simple physics. The more sensitive speaker is just, well more sensitive to the hiss and the hiss is most likely there because of the age of the pre/power...
Maybe my equipment is crappy aarmath, maybe.......

 

[keith_correa]

If levels are matched, and most variables being equal, the hiss should be audible over any speaker. Efficiency is out of the window in a case like this and is not a consideration.

 

[Fantastic]

Hi Rajesh,
Please explain to me how a relatively more efficient ....etc .....

Please save this thread and all that you have written. Then read it again in 10 years time when you are a little older .

 

[philipreji]

Hi Rajesh,
Please explain to me how a relatively more efficient and sensitive speaker in our times will manifest hiss aurally more than an inefficient speaker?

Hiss is cumulative thermal noise (Johnson noise) occurring in the resistances of an amplifier. It is proportional to the resistance value and amplifier bandwidth. The very first resistor (usually the volume control pot) will have maximum contribution to hiss because all of the amp gain happens after this resistor. That's why the hiss is substantially reduced when the input is shorted.

A speaker, by itself, cannot distinguish hiss from genuine audio signal. Therefore, if all other components and settings in an audio chain are the same, a more sensitive speaker should produce more hiss compared to a less sensitive speaker.

 

[jls001]

Simple test for those who maintain that hiss is speaker sensitivity agnostic: connect amplifier A to speaker A whose sensitivity is 87 dB/m/1W, a common enough value. Listen to hiss, if any, at volume setting V.

Next connect amplifier A to speaker B whose sensitivity is 100 dB/m/1W. Listen to hiss produced in the speaker, if any, at volume position V.

Which has louder hiss?

Why does electronics meant to power high sensitivity speakers necessarily have to be more silent than those powering more conventional sensitivity speakers? And why is the noise requirement even more stringent when powering ultra sensitive horn setups with circa 115 dB sensitivity?

 

[captrajesh]

Please explain to me how a relatively more efficient and sensitive speaker in our times will manifest hiss aurally more than an inefficient speaker?

Sure. First answer my simple questions.

1. For given volume setting of a given amp, which speaker would sound louder; a 84 dB one or a 86 dB?

2. What exactly is hiss? (Technically speaking)

 

[raghupb]

Why are we arguing to death about it?
The OP is not too bothered with this hiss since it is at high volume and he puts the ear close to tweeter.
The OP seems to be pretty satisfied with his purchase

Cheers,
Raghu

 

[keith_correa]

Why are we arguing to death about it?
The OP is not too bothered with this hiss since it is at high volume and he puts the ear close to tweeter.
The OP seems to be pretty satisfied with his purchase

You're absolutely correct! Die thread, die!

 

[jls001]

You're absolutely correct! Die thread, die!

Haha

Much ado about nothing

 

[Fantastic]

Just to wrap it up. What is 'hiss'. The definition is 'a sharp sibilant sound '...'as in 's' ' ... according to the dictionary .
In real terms it would be a band of frequencies approximately above 3Khz up to say 20KHz. Though most people cannot 'hear' above say 12KHz or 16 KHz.There might be a few exceptions.

The noise in an audio system is broadband and starts from a few hertz all the way to HF. The lower frequencies aren't so obtrusive and our sensitivity to them at low levels is very poor. So they don't bother us. Frequencies around about 3 Khz is the region where our ears are most sensitive. So the upper range frequencies become noticeable and we hear them as a form of 's' sound and is called hiss.
So while noise is actually broadband and contains all frequencies, the one that bothers us most audibly are the higher frequencies and they have been termed 'hiss' ! Since the tweeter is the one where all the HF signals go , we hear the hiss from the tweeter.

 

[raghupb]

Many of us on the forum, e.g old geezers like me, have lived with tape hiss, LP pop and crackle for ages.
If the music content appeals to one heart, minor niggles like this one can be safely ignored.
Enjoy the music, unless you hear dismemberment or unnatural sounds.
Cheers,
Raghu

 

[Fantastic]

Many of us on the forum, e.g old geezers like me, have lived with tape hiss, LP pop and crackle for ages.
If the music content appeals to one heart, minor niggles like this one can be safely ignored.
Enjoy the music, unless you hear dismemberment or unnatural sounds.
Cheers,
Raghu

Exactly !
It helps to grow old ! We get to understand what's REALLY important !

When one gets immersed in the music you soon forget the small irritations that you started with ! That phase usually stays during the remaining of the listening session.