It uses a Holmgren toriod which does have an electrostatic screen ( according to the manufacturer ).
I do realise this caused a bit of an argument here in 2014 ---and it caused arguments elsewhere as many questioned the size compared to a "real " Holmgren but I am open-minded on this as I don't have one in front of me..
So --is it marked Holmgren ?
I do realise this caused a bit of an argument here in 2014 ---and it caused arguments elsewhere as many questioned the size compared to a "real " Holmgren but I am open-minded on this as I don't have one in front of me..
So --is it marked Holmgren ?
I did not understand the Gotcha and smiley face...
Children somehow managed to connect the Xbox to 220 volts, and the supply blew...
It had been brought for nephews and nieces by a friend's daughter, and I got a hurried call as their new toy was broken
I knew a person who could repair the SMPS, and I do not remember if he left it at 110 in or wide band / 220 in, this was many years back
The Sony was damaged by kids who have their own kids now, that many years ago.
Children somehow managed to connect the Xbox to 220 volts, and the supply blew...
It had been brought for nephews and nieces by a friend's daughter, and I got a hurried call as their new toy was broken
I knew a person who could repair the SMPS, and I do not remember if he left it at 110 in or wide band / 220 in, this was many years back
The Sony was damaged by kids who have their own kids now, that many years ago.
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Yes, I had perused that thread and had taken notice of content and direction it had headed. Still I’m not convinced that there’s actually something truly special with the transformer since it’s primary role is only providing a specific voltage from the mains.
Also I have contacted NAD via email to their parts department and made an inquiry into trying to locate a replacement 120v transformer. Not holding my breath as to whether a new replacement part is even available or even going to cost friendly considering this is not a high end integrated amplifier.
In the mean time I have setup a search in eBay for a parts unit per chance one may show up in the near future.
Sorry Naresh, I was only acknowledging that I now understood as to what had actually happened to the equipment with regards to the damage.
I wasn’t sure if the step up / step down transformer was internally faulty and caused the damaged as opposed to being connected improperly by the children.
Here our plugs have round pins, and the American plugs have flat pins.
But some sockets have places for both kinds of pin, and adapters are there for the flat to round plugs.
India is 220V / 50 Hz, and US is mostly 110V / 60 Hz, some wiring is 220 between phases in the USA. Neutral is separate from ground here, distribution transformers have 2 or 4 wire secondaries.
Sony and Xbox came from the USA, and in both cases the children, in their impatience, caused damage, as they did not know the transformer had to be connected, they put it directly in the mains sockets, bypassing the transformers.
Just check the set is working, and then you can decide what to do.
A custom made transformer may be too expensive, you could look for an old or for parts set up for sale, and use that transformer.
Another way is to measure the secondary voltages, see what kind of circuit is there in the power amp section, and use the transformer from a similar set.
For example, STK modules were used by Sony, Sansui, Kenwood and so many others.
So you need not depend on NAD then.
One more thing, the Littelfuze units specifically say they cannot be used on 2 phase supplies. Just check what you have in the basement before connecting, as the NAD is a single phase unit.
But some sockets have places for both kinds of pin, and adapters are there for the flat to round plugs.
India is 220V / 50 Hz, and US is mostly 110V / 60 Hz, some wiring is 220 between phases in the USA. Neutral is separate from ground here, distribution transformers have 2 or 4 wire secondaries.
Sony and Xbox came from the USA, and in both cases the children, in their impatience, caused damage, as they did not know the transformer had to be connected, they put it directly in the mains sockets, bypassing the transformers.
Just check the set is working, and then you can decide what to do.
A custom made transformer may be too expensive, you could look for an old or for parts set up for sale, and use that transformer.
Another way is to measure the secondary voltages, see what kind of circuit is there in the power amp section, and use the transformer from a similar set.
For example, STK modules were used by Sony, Sansui, Kenwood and so many others.
So you need not depend on NAD then.
One more thing, the Littelfuze units specifically say they cannot be used on 2 phase supplies. Just check what you have in the basement before connecting, as the NAD is a single phase unit.
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Yes, I did see that about the LittelFuze transformer, Naresh....😉
Well today I was able to somewhat test the unit out in the basement 230v line.
I wired in this humongous male Frankenstein plug for my dryers 230v outlet and the NAD powers up and the little led first turned red then yellow for about 5 or 10 seconds and then I heard some type of relays click followed by the yellow led changing to green. I tested all the selection buttons i.e. phono, cd, tuner, aux and tape and all seemed to light up fine.
I stopped there as I didn't have any device to input a signal from or any speakers hooked up as I want to measure the DC-offset and bias parameters.
Also I got and a reply back from my inquiry to NAD parts (thanks Duncan for the links) on a 120v transformer and they have a replacement available for $90.40 plus $20.00 shipping.
Question is if the unit checks out okay after further testing is this NAD integrated worth investing another $110.40 plus tax?
Of course this is just asking for general opinions as I understand everybody will see things in a different light.
The NAD C320BEE is pretty well regarded and still sought after, usually selling around the US$100-$200. There is a warts and all technical review here: Review and Measurements of NAD C 320BEE PWR Amplifier | Audio Science Review (ASR) Forum
If I could criticise this review on anything it is that the reviewer thinks that 50 watts per channel is not enough, but that really depends on the listener, and I am not sure that opinion was based on listening tests where the C320BEE delivers close to 200W per channel peak into 4Ω loads - it's no slouch.
If I could criticise this review on anything it is that the reviewer thinks that 50 watts per channel is not enough, but that really depends on the listener, and I am not sure that opinion was based on listening tests where the C320BEE delivers close to 200W per channel peak into 4Ω loads - it's no slouch.
That's an interesting site John.
I was a bit puzzled by the testers comment here in bold from the paragraph below.
"In testing, without undue stress, the unit went into protection and would not reset until I cooled it off with a fan and left it off for a few minutes. Most amps survive my testing without going into protection mode since I only push them to max power for seconds."
Isn't driving an amplifier to its power limits even for a few seconds induced stress....😛
Other than that the unit seems very capable for it's design and modest output power.
I must admit that I didn't read the entire review. I do trust the reviewer as he does not seem to be swayed by marketing and is very consistent in how he reviews sound equipment. I do not doubt that what he reported is his real experience. However I have not heard of premature shut down of C320BEE amplifiers, and if it were a problem nad would have issued a technical service note. Actually, I do recall there is a tech note on the 320BEE, which you can download (along with the service manual) here: NAD C320BEE Stereo Integrated Amplifier Manual | HiFi Engine
Edit: I just checked, it is not to do with shutdown issues.
Edit: I just checked, it is not to do with shutdown issues.
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If it checks out okay on power, service the heat sink area, fresh compound, and lube the fan, there is usually a rubber plug under the sticker, oil and grease are both used together by me.
On power means playing music connected to speakers.
On power means playing music connected to speakers.
Yes, from further perusing that site I can see that reviewer is a no nonsense guy. I just thought his choice of words in describing the amps miscue while putting the power hammer all the way down was interesting.
Thanks for the links above. I have down loaded copies of all the pertinent information. The TSB from NAD removing a few components is simple enough to do.
That's the plan for tomorrow Naresh. I have the unit powered on as we speak and it's been on now for about 10 hours. Tomorrow will verify all the specs and test the unit first with some headphones and then on some speakers.
ps:
My unit doesn't have a fan, but I guess adding one is simple enough to do.
The review person cooled it off with a fan, sorry..
The economics of spending about the unit's fair value in repairs are your decision.
I have a Sony which is supposed to have a fan, display on but no output.
I got it for less than $2, a long term project pending since 2018. Needs STK 403-100, not available, so will put 7293, two in parallel.
The economics of spending about the unit's fair value in repairs are your decision.
I have a Sony which is supposed to have a fan, display on but no output.
I got it for less than $2, a long term project pending since 2018. Needs STK 403-100, not available, so will put 7293, two in parallel.
So I finally checked the parameters of this amp and the DC offset was measuring about 55.2 millivolts on the right channel speaker output terminals and 72.4 millivolts on the left.
The service manual specifies that the readings should be between 0v and 30mv.
So the amplifier was reading just about twice the recommended of what would be acceptable voltages. I didn’t bother to try dialing in the correct voltages at this point and just briefly tested the unit for sound on each channel along with the headphone port, volume, balance, treble, and bass control pots.
Everything is working fine except for the values noted above being out of specification.
Not comes the decision as to whether I go the route with using a $60 or $70 step up transformer or spend the $110 for the 120 volt transformer.
The logical side of my brain tells me to do the right thing and just buy 120v replacement transformer. But the cost conscious/practical side says you would probably be just fine getting the step up transformer and using the $50 saving to put towards another project.
What do you guys think....😛
The service manual specifies that the readings should be between 0v and 30mv.
So the amplifier was reading just about twice the recommended of what would be acceptable voltages. I didn’t bother to try dialing in the correct voltages at this point and just briefly tested the unit for sound on each channel along with the headphone port, volume, balance, treble, and bass control pots.
Everything is working fine except for the values noted above being out of specification.
Not comes the decision as to whether I go the route with using a $60 or $70 step up transformer or spend the $110 for the 120 volt transformer.
The logical side of my brain tells me to do the right thing and just buy 120v replacement transformer. But the cost conscious/practical side says you would probably be just fine getting the step up transformer and using the $50 saving to put towards another project.
What do you guys think....😛
VR11 and VR21 set the offset. Let the amp warm up for a few minutes before adjusting.
Whether to go the more expensive option depends on if the C320BEE is a keeper. Personally I think it a good amp and highly sought after. It will perform slightly better with the factory solution because the voltage regulation will be better with one transformer than two transformers in series.
On the other hand, a step down transformer is a handy thing to have if your playing with bits and pieces. You can even use it when servicing to step your 115Vac mains down to ½ to make circuits a bit safer to fiddle with.
I'd do the factory mod, or sell the amplifier to a foreign buyer if you don't want it.
Whether to go the more expensive option depends on if the C320BEE is a keeper. Personally I think it a good amp and highly sought after. It will perform slightly better with the factory solution because the voltage regulation will be better with one transformer than two transformers in series.
On the other hand, a step down transformer is a handy thing to have if your playing with bits and pieces. You can even use it when servicing to step your 115Vac mains down to ½ to make circuits a bit safer to fiddle with.
I'd do the factory mod, or sell the amplifier to a foreign buyer if you don't want it.
After looking at some more online reviews of this integrated amplifier and reading that entire thread from the link on this NAD unit. I’ve decided that I’m going to order the correct transformer from NAD Parts, John.
The replacement transformer is factory correct and plug & play. Which means that I could run this amplifier on my medical grade PowerVar voltage regulators and surge protector which provides clean/correct 115 volts of stable power after the mains and filters out errant DC noise spikes too.
Hi all,
Before I go ahead and purchase a brand new replacement transformer from NAD Parts I would like to know if the 120v Holmgren Toroidal power supply transformer in a NAD C372 parts unit can work in the NAD C320BEE as a direct swap in order to change out a 230v Holmgren Toroidal transformer in C320BEE.
I have the schematics from both units but I'm not skilled enough to discern from the schematics by looking at them if the voltages on the transformer are similar. Hoping somebody here can help me out in determining if they are similar enough for a swap.
I can get a real good deal on the NAD C372 parts unit for the transformer but obviously if it's not going to work than it's a moot point.
Before I go ahead and purchase a brand new replacement transformer from NAD Parts I would like to know if the 120v Holmgren Toroidal power supply transformer in a NAD C372 parts unit can work in the NAD C320BEE as a direct swap in order to change out a 230v Holmgren Toroidal transformer in C320BEE.
I have the schematics from both units but I'm not skilled enough to discern from the schematics by looking at them if the voltages on the transformer are similar. Hoping somebody here can help me out in determining if they are similar enough for a swap.
I can get a real good deal on the NAD C372 parts unit for the transformer but obviously if it's not going to work than it's a moot point.
They aren't the same , I am not saying with circuit modifications and some work you couldn't make it work , I am saying as it stands the voltages and winding's aren't similar.