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Just Bought Norge MOSFET Reference 2000 Stereo Amplifier

Wharfedale Diamond 11.1 & 11.2 Speakers

arun_chak

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Friends,

Just got in Norge 2000 stereo amplifier. Heard the demo of 1000 gold and 2000 mosfet. 2000 seemed a bit more smoother and punchier, however 1000 gold sound was bright. I however liked 2000 as I hear loud music. Cost was 15.7K in Chennai. During intial hookup I found that the sound suddenly dies and became low when I increased the volume to near 75%. I am using ELAC FS 58.2. However don't see the issue now. The sound is definitely great than my AVR Onkyo TX SR 607. Music seems more defined and pronounced. I am not an audiophile. Would appreciate if you can give me more inputs on this MOSFET amp.

Thanks
 

efernand1

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Hi

Congratulations on your purchase....

New speakers require a BREAK IN which means run them for 20-40 hours for optimal performance.....if a new amp or AVR is hooked up...it will work but allow it sometime to settle in ...synch with each other....I am sure you will like it even more as time flies by....

Mosfet amps are great and they throw good power continuously....just be careful of overheating ...else put a small cooling fan to keep the overall amp (heatsink area) cool
 

efernand1

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Hi,

The Tweeter is the most sensitive speaker part and hence any hum or hiss noise would be emitting from the amp or avr....check again and reconnect all wires step by step....typically most of us face grounding issues.....
 

arun_chak

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Hi,

The Tweeter is the most sensitive speaker part and hence any hum or hiss noise would be emitting from the amp or avr....check again and reconnect all wires step by step....typically most of us face grounding issues.....

Called up Norge today and the technician confirmed that there will be a low hiss sound at higher volume which is acceptable. But I think I am being very picky :). Also one thing he said was that not to run amp for a very long time on a high treble, this tends to heat up the device more.

BTW, the person seemed very supportive. He assured that I can call anytime whenever I have queries. Today I ran the amp for 5 hrs with different variety of music, and really loved it. Especially the base was punchier. The vocals were pronounced. String instruments came alive. And at times I felt like sitting in a live concert which was never the case in my Onkyo AVR. My neighbors might complain soon :D. Now I realize as why audiophiles swear by stereo music. Wished I had bought this earlier when the cost was lesser.
 

Hari Iyer

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Called up Norge today and the technician confirmed that there will be a low hiss sound at higher volume which is acceptable.

Never heard hiss sound at high volume levels in my amp though. The hiss should be because of unmatched mosfets at the output stage or transistors at the predriver stage.
 

arun_chak

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Never heard hiss sound at high volume levels in my amp though. The hiss should be because of unmatched mosfets at the output stage or transistors at the predriver stage.

Hari,

Yes I can hear a low hiss at high volume, which is only audible when you take your ears very close to the tweeters. Are you using Norge, or do you feel this is unacceptable?
 

Fantastic

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The hiss is coming from the input stage of the amp. Disconnect the source ( CD player or DVD player etc.) and short the input terminals . ( Signal lead to ground) . Then turn up the volume and see if you still get hiss. If you don't then you have been hearing residual hiss from the source.
If you do get hiss then it's from the amp itself. All amps have hiss . However if the level is sufficiently low you will not hear it. Hearing low level hiss right next to the tweeter with the volume turned up isn't too bad a situation ! The music will be so loud at that level it will mask any hiss which in any case will be inaudible at the listening position.

The volume control is seen as a resistance by the amp and all resistances produce thermal noise. That's why as you turn up the volume the amp sees a large resistance than at low volume and correspondingly the noise ( hiss) goes up. For well designed systems the level of hiss can be kept low by selecting components to minimise it. It isn't something you can wish away, it is just minimised by design.

Lot of factors control this including the noise generated by components, gain of the amp ,the speaker sensitivity the resistance of the volume control and or source resistance etc.
As long as it's inaudible ( at the listening position) at all listening levels it should be OK.
 

arun_chak

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The volume control is seen as a resistance by the amp and all resistances produce thermal noise. That's why as you turn up the volume the amp sees a large resistance than at low volume and correspondingly the noise ( hiss) goes up. For well designed systems the level of hiss can be kept low by selecting components to minimise it. It isn't something you can wish away, it is just minimised by design.

Lot of factors control this including the noise generated by components, gain of the amp ,the speaker sensitivity the resistance of the volume control and or source resistance etc.
As long as it's inaudible ( at the listening position) at all listening levels it should be OK.

Hi Fantastic,

Nice explanation, I also think it is acceptable. The hiss at high volume comes even when all source are plugged out, hence I am sure it is from the amp. As I said earlier, it is low and only audible when I bring my ears very close to the tweeter. Also looks like my speaker sensitivity is 90db, it may also contribute to this.

-Arun
 

Fantastic

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........ Also looks like my speaker sensitivity is 90db, it may also contribute to this.........-Arun

Absolutely ! :)

The average speaker is between 84 and 86 dB ! Some are 88dB. 90 dB and above is considered very sensitive.
Low level hiss with the volume wide open AT the tweeter is normal for your speaker. Don't worry about it.
 

shibashis

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I have had time to live with a Norge power for a couple of weeks now, and it is pretty great for its price. Even without the price factoring in the considerations it is a very decent power amplifier. If the Norge 1000 and 2000 are like their power amps then those are seriously good equipments at such great prices.
 

Fantastic

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The truth about amplifiers is that the state of amplifier design has risen to such levels today that 'most' amps being produced use one of a few generic good sounding proven circuits that's freely available worldwide.
So any Indian company can make very good amplifiers ( if they avoid picking some poor parts !) at decent prices. I'm sure Norge belongs to that group. They have been around along time and MUST know what the state of the art is today !
Don't worry about labels too much nowadays especially at the lower price end. Trust your ears. If it sounds good enough to you , it's worth buying ! ;)
Don't be too concerned about what others think of it. Their perspective could be completely different from yours AND no one can really make a bad amplifier today if they are into it seriously ! ;)

Differences could be there . Those that you like or do not like. But it will generally not be a bad sounding amp ! And we are not talking about 'good' or 'bad' ....just ..different ! :)
 

apk

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Don't worry about labels too much nowadays especially at the lower price end. Trust your ears. If it sounds good enough to you , it's worth buying ! ;)
Don't be too concerned about what others think of it. Their perspective could be completely different from yours AND no one can really make a bad amplifier today if they are into it seriously ! ;)

+1 to that

Audio, like food, is a very personal thing! What excites someone may not sound much to another. Norge is one of the better entry level amplifiers out there, and as long as the rest of the components are upto the mark, you should be happy! Mr Bajaj, who runs Norge Audio has been around in the audio industry for quite a few decades. Here is an interesting article about him
Radio Norge, shared by FM rishiguru sometime back.

Best,
APK
 

aarmath

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Absolutely ! :)

The average speaker is between 84 and 86 dB ! Some are 88dB. 90 dB and above is considered very sensitive.
Low level hiss with the volume wide open AT the tweeter is normal for your speaker. Don't worry about it.

I hope you are joking mate!
SPL efficiency has absolutely NOTHING to do with low level Hiss. It means that even a whinny amp will be able to power these speakers (say 88 dB and above....)
If you are getting a hiss then you have a crappy amp or you you have to fix that amp and hope it is not crap.

And for the record - At Rs. 15 K approx don't expect the amp to be approaching even reasonably good performance.
 

Fantastic

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No I'm not joking !
ALL amps have inherent background noise . It's only the levels that differ.

1. Some amps have hiss even with the volume turned down . This is due to the circuitry and with modern designs this shouldn't happen or if it's audible it should only be so with your ear right next to the tweeter.
2. If the speaker is very sensitive the hiss will sound louder on it than a less sensitive speaker under the same conditions.
3. When the volume levels are turned up (without an input signal ) and hiss increases, it's because the amp is seeing the input resistance increasing which has inherent hiss ( due to laws of physics) and that is amplified. The amount depends on component values. Some well designed amps have no "audible hiss" even with the volume turned up. That does not mean no hiss. It means too low to be heard easily !
4. If you short the input and check, the hiss should go down as the amp now sees a lower input resistance and so noise will be less. Besides noise will be maximum at some in between point of the volume setting rather than the two extreme settings.

Many amps with some low level hiss right at the speakers still sound great. Remember that you don't hear hiss at the listening position. Don't use sweeping statements like 'if you hear some hiss the amp is crappy' ! 15 K is a great price for a decent amp. It's possible that the performance could be quite close to expensive amps. EVEN THAT isn't a joke ! I can't say anything about this amp, but price doesn't tell you everything ! If you have designed and built amps for years you will know what all this is about.

Also remember that when you say 'comparison of amps' you aren't talking about a comparing a 200 watt amp with a 20 watt amp and saying the 20 watter can't match up. That's silly. You play them both at the same level that doesn't overload the small amp ....typically in the 2 to 5 watt range and compare the sound. You are trying to compare sound quality and not power levels. For some people a 20 watt per channel amp produces far more volume than they want ! 2 watts per channel on an average speaker is quite loud ! Your ears sensitivity is exponential. 20 watts is not 10 times louder than 2 watts !
 
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aarmath

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Yes, all amps have inherent hiss. What matters is the amount of Hiss that enters in the audible range of listening to music. In today's technology, a half decent amp has reasonable amounts of Hiss only entering in the higher volume levels. I say, yet again, this has nothing to do with efficiency of the speakers. Back a few decades ago when component quality was not so good, this hiss was a problem. Not a problem in today's amps.
Well, frankly, I have found Norge to be quite below average. Let us not make the amp's relatively crappy performance a virtue simply because it is a "MOSFET" amp that sells for about INR 15 K.
And yes, if the above ounds like a sweeping statement, then either you gotta redial your own sensitivity meter or at the very least do the right research before you build a factually incorrect co-relation between Amp Hiss and Speaker sensitivity because that is plain wrong. The last thing I would want is to have this kind of drivel being taken verbatim by inexperienced forum members.

No I'm not joking !
ALL amps have inherent background noise . It's only the levels that differ.

1. Some amps have hiss even with the volume turned down . This is due to the circuitry and with modern designs this shouldn't happen or if it's audible it should only be so with your ear right next to the tweeter.
2. If the speaker is very sensitive the hiss will sound louder on it than a less sensitive speaker under the same conditions.
3. When the volume levels are turned up (without an input signal ) and hiss increases, it's because the amp is seeing the input resistance increasing which has inherent hiss ( due to laws of physics) and that is amplified. The amount depends on component values. Some well designed amps have no "audible hiss" even with the volume turned up. That does not mean no hiss. It means too low to be heard easily !
4. If you short the input and check, the hiss should go down as the amp now sees a lower input resistance and so noise will be less. Besides noise will be maximum at some in between point of the volume setting rather than the two extreme settings.

Many amps with some low level hiss right at the speakers still sound great. Remember that you don't hear hiss at the listening position. Don't use sweeping statements like 'if you hear some hiss the amp is crappy' ! 15 K is a great price for a decent amp. It's possible that the performance could be quite close to expensive amps. EVEN THAT isn't a joke ! I can't say anything about this amp, but price doesn't tell you everything ! If you have designed and built amps for years you will know what all this is about.

Also remember that when you say 'comparison of amps' you aren't talking about a comparing a 200 watt amp with a 20 watt amp and saying the 20 watter can't match up. That's silly. You play them both at the same level that doesn't overload the small amp ....typically in the 2 to 5 watt range and compare the sound. You are trying to compare sound quality and not power levels. For some people a 20 watt per channel amp produces far more volume than they want ! 2 watts per channel on an average speaker is quite loud ! Your ears sensitivity is exponential. 20 watts is not 10 times louder than 2 watts !
 
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