Anatomy of Norge 1000 GOLD Stereo Integrated Amplifier

[vinyl]

If you intend on seeking help of a technician, I would suggest a easy 'hack' of swapping the default power on/off switch with a 'DPDT' switch that will shut off both the phase and neutral supply at the same time.

DPDT image:

Thanks Sarith,

I will first check out with a technician if a DPDT switch can be accomodated or not, if not then I will use a DPDT switch outside the amp, leaving the amp's switch on, and perhaps also provide a grounding. Peculiarity is that the Norge guys say slight current is induced to the body because of the high power torroidal tranformer, but their service center in kolkata says that is not normal.

 

[vinyl]

Providing ground is easy and worth solution. It will add safety and quietness too, will take away some noise from PS.

I have already added a grounding, and as Sarith says I will add a DPDT outside the amp.
Other forum members who use Norge amps, should check out if they have this problem.

 

[sarith]

Thanks Sarith,

I will first check out with a technician if a DPDT switch can be accomodated or not, if not then I will use a DPDT switch outside the amp, leaving the amp's switch on, and perhaps also provide a grounding.

From images, it seems like the default power switch of Norge is a compact SPST or SPDT rocker switch. It doesn't seem like a DPDT rocker switch will fit. A switch outside the amp sounds good.

DPDT rocker, slide or toggle switch will do but an external power switch using toggle switch would be easier to assemble.

 

[ShutterX]

Slightly OT:

I am planning to buy the 1000. I have 2 bookshelf options to pair with this unit.

1) Micca MB42x
2) Pioneer SP-BS22

Has anyone ever heard the 1000 with these speakers? Any idea of their matching?

 

[vinyl]

From images, it seems like the default power switch of Norge is a compact SPST or SPDT rocker switch. It doesn't seem like a DPDT rocker switch will fit. A switch outside the amp sounds good.

DPDT rocker, slide or toggle switch will do but an external power switch using toggle switch would be easier to assemble.

Norge amps power switch is SPST.

 

[vinyl]

Guys, let us discuss why it happens?
You have toroidal transformer in power supply. It has primary coil wound inside over heavy core. That winding is multilayer. So one end is near core and other end is at outer layer. Now if you connect live wire from inside end then outer end is neutral and outer layer is nearing to low voltage. If you interchange live and neutral then outer primary winding layer will be at higher alternating voltage of mains.
Now over this same primary coil, you add either shield layer which could be optionally grounded or wind secondary coil. Now you have two copper conductors overlapping and creating capacitor which could couple mains frequency and 250V. Though it may not carry large current but voltage is enough to lit the tester. It is worst when live is upper layer of primary and neutral inside near core. And vice verse.
Solutions:
Either you ground internal shield layer if any or correct wire positions. Otherwise you may be having switch wrongly put on neutral wire. So in absence of ground it may couple mains to secondary side which generally 0 reference connected to chassis.

I would like to ask one thing. Assuming that everything is ok, i.e. wiring is done correctly, then will a toroidal transformer still provide some induced current to the amp's body ?
Norge guys say it is normal because of the high power tranformer. If so, then what about other amps like Marantz and others that have toroidal transformers.

 

[omishra]

Yes. It is possible. And its capacitor made between primary and secondary windings. While you connect RCA and if somewhere it grounds chassis then you even won't notice it.

 

[wlg]

Visited the Norge outlet at Matunga with a friend who purchased a Norge 125W amp and got it fit with a vol remote, took half an hour to fit the servo motor (at an extra cost).

 

[samlo]

actually i am a technician and audio gear repairing, reconditioning is my hobby. i
never buy indian amps, instead i buy used imported audio amps and systems,which are available in mumbai at very reasonable price.some amps needs minor repairing but any good technician can manage it.

 

[dazzwilliams]

Here are the final upgrades to the Norge 1000.

1. Speaker Protection Circuit: Removes the irritable turn on "pop" sound and provides instant turn off and DC protection.

2. Default preamplifier Mod: Removed on board TL072 opamps. Replaced with IC bases. Tried NE5532 followed by Burr Brown OPA2134s.

3. Installed a separate preamplifier based on the well known Burr Brown OPA627s with fixed gain jumpers bypassing volume control (volume controlled by DAC) with instant switching between the two pre amplifiers. Both sound different. Tired right now to compare will do it later.

4. Replacement of supply capacitors by 4x10000 microfarad Nichicons improved the bass in the lower octaves (was especially helpful for bass heavy tracks).

Sorry for bumping up this old thread. I just bought a used Norge Concerto Gold 1000 from a friend (he purchased it new in 2019).
Yet to receive the amp and I'm curious whether these improvements have been incorporated over these years or not.

Was reading up the excellent analysis by @rishiguru and thoughtful upgrades by @Audiodoc. I was wondering if the same can be done. The Norge 1000 is surely a VFM option for budget audio enthusiasts.

@rishiguru are you still using your Norge? Any other upgrades done other than adding cooling fans?

 

[akd06]

The speaker protection board comes for 500 bucks. Wanted to etch one for myself but I can only make single sided boards. Stumbled across the circuit from 8audio Hong Kong. Great double sided pcb. Few points to keep in mind.

1. The circuit uses 12V - 18V AC for the relays. However the problem with the Norge is that the supply voltage of the secondary is 15-0-15V so you will believe that connecting a 0-15V supply will make it work. However that seemed to be wrong. As soon I turned the power on the bridge rectifier on the PCB smoked (1A version). Then I derived the supply from the regulated DC side of the power supply board. Everything works alright now. The regulated 15V is reduced to regulated 12V by 7812 regulator on the board.

2. The results of the circuit being introduced is that the turn on pop is no more. On turning on the relays are energized indicated by the LED on the PCB. After a few second the speaker outputs get connected via the relay. Secondly the problem of music being played even after turning the amp off due to stored energy in the capacitors is also solved.

3. The circuit also provides DC protection.

If you plan to book more circuits from 8audio kindly go for a group buy. Shipping and customs will be cheaper. I have searched a lot on the net but they provide the cheapest DIY accessories. So I am in in case of group buys.

If some one plans to DIY the PCB I am in will deduce the schematics and design the same though I believe the PCB is value for money as in India it will be a toiling task to obtain all the components.

Kindly share your contact number for info about speaker protection circuit

 

[akd06]

The speaker protection board comes for 500 bucks. Wanted to etch one for myself but I can only make single sided boards. Stumbled across the circuit from 8audio Hong Kong. Great double sided pcb. Few points to keep in mind.

1. The circuit uses 12V - 18V AC for the relays. However the problem with the Norge is that the supply voltage of the secondary is 15-0-15V so you will believe that connecting a 0-15V supply will make it work. However that seemed to be wrong. As soon I turned the power on the bridge rectifier on the PCB smoked (1A version). Then I derived the supply from the regulated DC side of the power supply board. Everything works alright now. The regulated 15V is reduced to regulated 12V by 7812 regulator on the board.

2. The results of the circuit being introduced is that the turn on pop is no more. On turning on the relays are energized indicated by the LED on the PCB. After a few second the speaker outputs get connected via the relay. Secondly the problem of music being played even after turning the amp off due to stored energy in the capacitors is also solved.

3. The circuit also provides DC protection.

If you plan to book more circuits from 8audio kindly go for a group buy. Shipping and customs will be cheaper. I have searched a lot on the net but they provide the cheapest DIY accessories. So I am in in case of group buys.

If some one plans to DIY the PCB I am in will deduce the schematics and design the same though I believe the PCB is value for money as in India it will be a toiling task to obtain all the components.

Since power supply of the speaker protection circuit require ac voltage, how can you

The speaker protection board comes for 500 bucks. Wanted to etch one for myself but I can only make single sided boards. Stumbled across the circuit from 8audio Hong Kong. Great double sided pcb. Few points to keep in mind.

1. The circuit uses 12V - 18V AC for the relays. However the problem with the Norge is that the supply voltage of the secondary is 15-0-15V so you will believe that connecting a 0-15V supply will make it work. However that seemed to be wrong. As soon I turned the power on the bridge rectifier on the PCB smoked (1A version). Then I derived the supply from the regulated DC side of the power supply board. Everything works alright now. The regulated 15V is reduced to regulated 12V by 7812 regulator on the board.

2. The results of the circuit being introduced is that the turn on pop is no more. On turning on the relays are energized indicated by the LED on the PCB. After a few second the speaker outputs get connected via the relay. Secondly the problem of music being played even after turning the amp off due to stored energy in the capacitors is also solved.

3. The circuit also provides DC protection.

If you plan to book more circuits from 8audio kindly go for a group buy. Shipping and customs will be cheaper. I have searched a lot on the net but they provide the cheapest DIY accessories. So I am in in case of group buys.

If some one plans to DIY the PCB I am in will deduce the schematics and design the same though I believe the PCB is value for money as in India it will be a toiling task to obtain all the components.

Since the power supply of the speaker protection circuit requires ac supply, how can you get supply to spc by connecting 15 0 15v dc side (ps to Pre amp) of norge amp? Kindly explain please. I want a SPC for my norge 4242 amp but facing problem for AC 12v supply. Am thinking to use attached SPC from The Audio Craft.