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NAD C 298 Power Amplifier With Purifi Eigentakt Amplification

nothingman

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It is a common unfortunate problem and also an easy fix via software update over the USB service port by authorized personnel.
My unit is working just fine. I think only the first ones had this issue

Can you please elaborate on what you know of the USB-based service? Did you send one in yourself or hear of that happening? Any idea how to contact a human at NAD who can address this? I’ve emailed them twice, three weeks ago and four days ago, and have heard nothing back since.
 

nothingman

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Finally spoke to NAD and have a thorough update. Instead of replying to my email they called me and were very polite and helpful.

There is indeed a firmware problem with some early C298 units. Luckily it’s not a hardware problem. It does not affect all units within a certain serial number range, so everyone just needs to keep an eye on their unit for malfunction.

As suspected, the basis of the problem is a false power protect trigger.

How to check your firmware version:

In operating mode: press and hold the power button for between 5 and 10 seconds. Once you let go, the power light should flash once, then the bridge mode light will flash a certain number of times. Early units like mine (both my faulty unit and the new replacement) flash seven times to indicate v1.07. The fixed firmware is v1.08, which would of course mean eight flashes.

NAD HQ sent out a service bulletin in late December about this issue. All distributors should know about the problem via the service bulletin. Not all service centers will have seen this problem before and may not be aware of the problem.

Any NAD service center should be able to perform this firmware update, but they will need a physical firmware update kit specific to this job, so if you contact them they will need some lead time to get the kit if they haven’t performed this service before.

Personally, I already sent back my faulty first unit but will keep vigilant on this second one and get it serviced if anything comes up. This will be covered by NAD’s warranty for two years (at least that’s how long the warranty is in the US).
 

lappy

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Finally spoke to NAD and have a thorough update. Instead of replying to my email they called me and were very polite and helpful.

There is indeed a firmware problem with some early C298 units. Luckily it’s not a hardware problem. It does not affect all units within a certain serial number range, so everyone just needs to keep an eye on their unit for malfunction.

As suspected, the basis of the problem is a false power protect trigger.

How to check your firmware version:

In operating mode: press and hold the power button for between 5 and 10 seconds. Once you let go, the power light should flash once, then the bridge mode light will flash a certain number of times. Early units like mine (both my faulty unit and the new replacement) flash seven times to indicate v1.07. The fixed firmware is v1.08, which would of course mean eight flashes.

NAD HQ sent out a service bulletin in late December about this issue. All distributors should know about the problem via the service bulletin. Not all service centers will have seen this problem before and may not be aware of the problem.

Any NAD service center should be able to perform this firmware update, but they will need a physical firmware update kit specific to this job, so if you contact them they will need some lead time to get the kit if they haven’t performed this service before.

Personally, I already sent back my faulty first unit but will keep vigilant on this second one and get it serviced if anything comes up. This will be covered by NAD’s warranty for two years (at least that’s how long the warranty is in the US).
Thanks for the info. Just checked my early model, I have v1.07. Will contact my dealer and ask for update.
 

nothingman

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Latest v5 of the owners manual is now live on their website. This time they fixed the instructions relating to auto-on and auto-off (pages 5 and 6). This is something I highlighted in an earlier post as being super unclear/inaccurate.
 

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lappy

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Latest v5 of the owners manual is now live on their website. This time they fixed the instructions relating to auto-on and auto-off (pages 5 and 6). This is something I highlighted in an earlier post as being super unclear/inaccurate.
I shudder to think that there has been hardware fixes since my early model.
 

nothingman

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The tech I spoke to made it sound like the hardware has all been the same. It hasn’t been out that long, right? It’s just that the v1.07 firmware has a bug that crops up randomly in some units but not many. I would guess their main problem is that there’s a bunch of 1.07 units out there altogether so they’re gonna be dealing with this for a while.
 

RGibran

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Interestingly, the power button is disabled when trigger cable connected. Disconnecting allowed me to check firmware version. My replacement unit dropped shipped from Lenbrook America is v1.08. My defective unit was dropped shipped from them as well. It appears they're letting the public do the discovery of faulty units for them.
 
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nothingman

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Interestingly, the power button is disabled when trigger cable connected. Disconnecting allowed me to check firmware version. My replacement unit dropped shipped from Lenbrook America is v1.08. My defective unit was dropped shipped from them as well. It appears their letting the public do the discovery of faulty units for them.

Good to hear v1.08 units are already out.

That part about the power button is normal in my experience with other amps.
 

klnhu

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Finally spoke to NAD and have a thorough update. Instead of replying to my email they called me and were very polite and helpful.

There is indeed a firmware problem with some early C298 units. Luckily it’s not a hardware problem. It does not affect all units within a certain serial number range, so everyone just needs to keep an eye on their unit for malfunction.

As suspected, the basis of the problem is a false power protect trigger.

How to check your firmware version:

In operating mode: press and hold the power button for between 5 and 10 seconds. Once you let go, the power light should flash once, then the bridge mode light will flash a certain number of times. Early units like mine (both my faulty unit and the new replacement) flash seven times to indicate v1.07. The fixed firmware is v1.08, which would of course mean eight flashes.

NAD HQ sent out a service bulletin in late December about this issue. All distributors should know about the problem via the service bulletin. Not all service centers will have seen this problem before and may not be aware of the problem.

Any NAD service center should be able to perform this firmware update, but they will need a physical firmware update kit specific to this job, so if you contact them they will need some lead time to get the kit if they haven’t performed this service before.

Personally, I already sent back my faulty first unit but will keep vigilant on this second one and get it serviced if anything comes up. This will be covered by NAD’s warranty for two years (at least that’s how long the warranty is in the US).

The warranty from the german Distributor is 5 Years - but only after registration within a fixed time.
 

muslhead

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Since it appears as if NAD has corrected this problem, is it possible to get some feedback from those who may be using it in bridged mode since i am in the market and wondering if i should pull the trigger (no pun intended). I have seen the measurements so, unfortunately (and please dont ban me), I am looking for opinions/feedback (sacrilegious I know on a objective-based forum) not on the sound but anything else of note.
TIA
 
D

Deleted member 24907

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It is worth noting that "disappointing" for a DAC means it was a 90db sn ratio, still close to the limits of 16 bit audio and likely an inaudible difference in sound from the best measuring DACs.
Hi there. I own the nad c368 with a burr brown DAC. Not the same as the one in the c658. Does anyone know how this dac measures? I am thinking of this amp as preamp for the c298.
 

Canth

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Hi, I have positioning problems. can you confirm depth is 390mm or 15 3/8 inches? Thanks.

the depth of the unit is 355mm. However, this is measured without any cables attached to it. The speaker terminals add an extra 25 mm (more if you use banana plugs) and the xlr/rca cables obviously also take up some space. I'm guessing you will need at least 390 mm to make it all fit. 400 mm would be better.
 
D

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the depth of the unit is 355mm. However, this is measured without any cables attached to it. The speaker terminals add an extra 25 mm (more if you use banana plugs) and the xlr/rca cables obviously also take up some space. I'm guessing you will need at least 390 mm to make it all fit. 400 mm would be better.
I have the c368. The centre of the support cap is 5 cm from the front. This means it can be placed that much hanging over the front of your cabinet. I don't know about the c298.
 

ehabheikal

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Nc252mp and naim xs2 - sounds similar to hypex with more control and overall aounds fuller - im no expert - what works well is no custom trigger as with nc252mp and no more power down pops - fixed gain xlr and aub connexted to rca out on c658

what is the problem with the nc252 trigger?
Do you think the nc252 is a good value or go for purifi?
 

lappy

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I just dropped a request at NAD support regarding if it is possible to update to FW 1.08 by myself. We'll see what they say. I hate sitting with 1.07.
 

nothingman

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I just dropped a request at NAD support regarding if it is possible to update to FW 1.08 by myself. We'll see what they say. I hate sitting with 1.07.

They told me in no uncertain terms that it’s only possible via service center. The service center needs to have specific hardware to do a C298 firmware update as well, so first you need to notify the service center than you need this particular service, then they get in touch with NAD HQ to be sent the necessary hardware. Definitely a bummer it isn’t possible via a usb key sent to customers.
 

nick-v

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I know it's a little tough to say based on the measurements that have been posted so far, but are we expecting the C298 to perform about as well as an ATI 522NC regarding SINAD? It's definitely at a more attractive price point.
 

KarVi71

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I know it's a little tough to say based on the measurements that have been posted so far, but are we expecting the C298 to perform about as well as an ATI 522NC regarding SINAD? It's definitely at a more attractive price point.

Its hard to say, but I would suspect it measures about as well as the NAD M33 (the AMP part of the measurements), as it shares the same power amplifier technology and as far as I know also the same SMPS or one very much like it.

https://www.audiosciencereview.com/forum/index.php?threads/nad-m33-streaming-amplifier-review.17302/

It could possibly be even better, as its a much simpler than the M33 in many regards, and the signal path should be shorter also.

In many ways the C298 is very much like the M33, just with a cheaper chassis and without the preamp / streaming front end.

I really hope Amir gets to measure one soon.
 
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Kal Rubinson

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In many ways the C298 is very much like the M33, just with a cheaper chassis and without the preamp / streaming front end.
........and it is easily bridged, for the power hungry/needy.
 
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