Anatomy of Norge 1000 GOLD Stereo Integrated Amplifier

[Teja]

I am extremely shocked to see, TL072 opamp pre inside Norge 1000.It is one of the worst opamps for 10Rs or so. may be norge have tried to do all with local components.

Are they really that cheap?.... then there is the first mod waiting right there.

modding thread for the norge is needed

+1 to that :thumbsup:

I hope this thread would provide the necessary motivation for a modding thread. I picked up an used Norge 2060 recently and would like to see some mods that can improve SQ. Hmm..... maybe I should open it up and post some pics. I can't do a proper tech review like Rishi, but at the least it will help to compare the 1000 and the 2060. Will plan for that this weekend.

Cheers.

 

[quad]

This amp, while neatly built, is clearly on a budget.
A few things I noticed -

1) Heat sink - I think they are able to get away with a smallish
one, as the MS chassis is probably acting as a spreader.

2) 78xx/79xx are definitely not low noise. Older, cheap op-amps.

3) No speaker protection circuit either for DC offset or pop protection.

4) No fancy caps, of course.

5) PCBs seem to be the cheaper paper phenolic type.

6) No Boucherot/Zobel network on output.

7) No bias compensation transistors seen on heat sink.
What amp topology is this using?

One can do better either by going for a late 70s Japanese transistor
amp, or following the DIY route.

 

[rishiguru]

.......... I picked up an used Norge 2060 recently and would like to see some mods that can improve SQ.

Hmm..... maybe I should open it up and post some pics. I can't do a proper tech review like Rishi, but at the least it will help to compare the 1000 and the 2060. Will plan for that this weekend. Cheers.

Well it will be great to have some internal shots of Norge 2060. More over we can now compare the 1000 & 2060 since it is said they follow the same topology.

Try to get the shots in those areas where i have done for 1000. And state what ever is written on transformer, power amps & op-amps.

Opening the 2060 will be easy, just four screws and the hood goes of.

Waiting for the shots impatiently.:licklips:

 

[sudhishkv]

Very nicely documented article and very clear snaps. I badly wanted to know about the internals of Norge since I heard about it. You have fullfilled my wish. Thank you very much!

 

[Audiodoc]

@ quad

Definitely one should understand it is a budget amp.

1. You are right in an air conditioned room the norge 1000 hardly heats up much at 12 o'clock position that I mostly use it.

I was surprised that rishiguru had to use two fans.

2. The power regulators 7815/7915 may not be the best for regulation as stated but they are still better than an unregulated supply.

3. Yes protection circuits are missing especially the power on pop is quiet audible but protection circuits are costly around 2K.

4. If we calculate the component cost for a DIY project the parts will cost around 7 to 8K.

5. As already commented upon the TL072 is a dual op amp belonging to the same op amp family as the quad opamp TL074 and are regarded relatively better than the TL082 / TL084. It is the TL082 family which is cheaper at round 20 bucks.

http://www.ti.com/lit/ds/symlink/tl071.pdf

 

[jaudere]

Wow. This thread is turning out to be a great tutorial for novices like me. Never knew that there are so many things to be looked at in an amp. Thanks to Rishiguru & all guys contributing this.

 

[spirovious]

So can we turn Norge amp to a decent hifi amp?compared to midrange one?

 

[reubensm]

although i am not a great fan of Norge, this is a splendid write up...thanks!!

 

[kaushik]

Are they really that cheap?.... then there is the first mod waiting right there.

That 10 or 20 Rs is india retail price , in china they sell for 60cents i..e. Rs1.20/- approx

I know because i used to see the sample /bulk pricing of components in previous company
.
Any way this thread will snatch the bread and butter of Norge Audio , that should not be the intention .... there are lott other expenditures company has to bear.
Mods possible :
(mainly expert diy guys can do these well)
1. Swap with a good pre , dont mod the existing .. grab some OPA dual opamp pre design, swap with TLE2142 /LME49990 OPAMPs or good members of AD-series [ask me if u want any i have a supplier ].. if prefer discrete go for a 2sk170 based pre
2. Good PSU for pre atleast ... use the minireg from DIyAudio
3. remove the outer plastic from Cat5 copper wires , solder on top of the thin lines of the cheap PCB
to allow better current handling
4. Input caps to pre should be good paper caps or russian PIO [import]
5. operate the 7815 guys with these regulator booster - pink fish media
6.add power on delay to avoid pop sound CircuitDB | Power-On Time Delay Relay
if sound does not improve come to me i will give refund for exp on the mods

 

[Teja]

Well it will be great to have some internal shots of Norge 2060.... Waiting for the shots impatiently.:licklips:

I will do it this weekend and post the pics by Sunday evening.

So can we turn Norge amp to a decent hifi amp?compared to midrange one?

IMO, Norge is already a decent hi-fi amp. But yes, if it can be made better with some easy mods, then that would be really nice to know (and do).

Any way this thread will snatch the bread and butter of Norge Audio , that should not be the intention .... there are lott other expenditures company has to bear.

I am sure that is not the intention. This thread lays out the good & not-so-good of Norge for everyone to see.

6.add power on delay to avoid pop sound

Hmm... I do not notice the power-on pop with my Norge 1000. But I hear it with the Norge 2060.

Cheers

 

[srinisundar]

That 10 or 20 Rs is india retail price , in china they sell for 60cents i..e. Rs1.20/- approx

I know because i used to see the sample /bulk pricing of components in previous company
.
Any way this thread will snatch the bread and butter of Norge Audio , that should not be the intention .... there are lott other expenditures company has to bear.
Mods possible :
(mainly expert diy guys can do these well)
1. Swap with a good pre , dont mod the existing .. grab some OPA dual opamp pre design, swap with TLE2142 /LME49990 OPAMPs or good members of AD-series [ask me if u want any i have a supplier ].. if prefer discrete go for a 2sk170 based pre
2. Good PSU for pre atleast ... use the minireg from DIyAudio
3. remove the outer plastic from Cat5 copper wires , solder on top of the thin lines of the cheap PCB
to allow better current handling
4. Input caps to pre should be good paper caps or russian PIO [import]
5. operate the 7815 guys with these regulator booster - pink fish media
6.add power on delay to avoid pop sound CircuitDB | Power-On Time Delay Relay
if sound does not improve come to me i will give refund for exp on the mods

Nice one Kaushik.. If possible any members who own Norge can venture into and Mk1 version of norge can be released Others like us who were watching can jump into it on conclusion.

Just for interest sake, how much the total cost for mod will be involved???

 

[omishra]

This amp, while neatly built, is clearly on a budget.
A few things I noticed -
7) No bias compensation transistors seen on heat sink.
What amp topology is this using?

That may be not required for transistors with -ve temp coefficient. means it heats its internal resistance decreases. So no thermal runaway occurs. Here BJT seems in same category. Its(thermal compensation in biasing) must only if +ve temp coefficient transistors used. e.g. HEXFETs.

 

[rishiguru]

.... Any way this thread will snatch the bread and butter of Norge Audio , that should not be the intention .... there are lott other expenditures company has to bear.......

A very important point to note, as put up by kaushik.

Norge Audio products may not be able to achieve the same levels of performance as international brands, but at the same time their products cost one third of these international brands. Their products provide the first step for novices like me to the audiophile world & Norge have been a supreme VFM manufacturer.

As pointed out by AudioDoc, the hardware of Norge 1000 alone costs 8K. I got the amp at 10K. So, think about the nomininal profit Mr. Bajaj is making.

---------------

I also urge others to stop comparing Norge 1000 with second hand amps. Think of my case. I got the INR 10K Sony bookshelves at 1.5K. Now, if i start comparing them with other 1.5 K chepo Chinese bookshelves, the Sony's will always come back as a winner. But this kind of comparison is unjustified.

So please stop comparison between first hand Norge 1000 with other second hand amps.

Better compare second hand Norge 1000 with other second hand amps.

 

[Audiodoc]

I want to clarify one point as a DIYer.

Price of the Norge 1000 will come to 7-8000 for a DIYer not for the manufacturer. Whenever I go to an electronics dealer for some resistors he will ask be to buy atleast 100 on the contrary if I buy just one have seen people asking for 5 bucks for a resistor. Similar is the case for capacitors and other passive components.

The costliest component in the Norge is the toroidal transformer 2-3K, followed by active components and capacitors.

I am planning to introduce a power on delay circuit to get rid of the annoying switching on "pop".

The worst nightmare for a Diyer is to get a good enclosures ranging from 1000 to 12000k in India.

 

[Hiten]

Just to clarify some misunderstandings.
I am not at all underestimating norge amplifier. I recommended to mod just to improve the amp. It could be any amp. Because I have seen across various forum people who have technical knowledge mod even Arcam and Bryston amps hyeah:.
And all mods can not be called improvements as some mods can be subjective.
Regards

 

[spirovious]

+1 to above,if some serious mods are applied,may we take norge to next level.

 

[rishiguru]

One odd question.

When was Norge 1000 & Norge 2060 released in the market for the first time?

Just for my curiosity.

 

[sudhishkv]

Delay circuite like this one? Looks simple to implement.

Designing your own delay circuit - DIYMA.com - Scientific Car Audio - Truth in Sound Quality

I want to clarify one point as a DIYer.

Price of the Norge 1000 will come to 7-8000 for a DIYer not for the manufacturer. Whenever I go to an electronics dealer for some resistors he will ask be to buy atleast 100 on the contrary if I buy just one have seen people asking for 5 bucks for a resistor. Similar is the case for capacitors and other passive components.

The costliest component in the Norge is the toroidal transformer 2-3K, followed by active components and capacitors.

I am planning to introduce a power on delay circuit to get rid of the annoying switching on "pop".

The worst nightmare for a Diyer is to get a good enclosures ranging from 1000 to 12000k in India.

 

[quad]

555 delay time - cheap, and simple -

DIY Audio Projects Forum • Simple Turn On Delay Circuit (Relay) Amplifiers & Speakers

 

[omishra]

I see they very good VFM amps and no one can beat the value, even DIY. I am doing it from long time, almost 20 years. Still these are interesting option to buy ready made rather than all headache if value is concerned.

Please look into these if you are looking any mod
speaker protection kit | eBay