My first defective unit would play music for hours, like 6-14 before shutting down. Sometimes it would play for 14 hours without shutting down. The problem was very intermittent. Replacement unit is V1.8 with no issues.
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NAD C 298 Power Amplifier With Purifi Eigentakt Amplification
My first defective unit would play music for hours, like 6-14 before shutting down. Sometimes it would play for 14 hours without shutting down. The problem was very intermittent. Replacement unit is V1.8 with no issues.
Hot off the presses. New Absolute Sound review. Robert Harley likes what he hears!
https://www.theabsolutesound.com/articles/nad-c658-streaming-dac-and-c298-power-amplifier
https://www.theabsolutesound.com/articles/nad-c658-streaming-dac-and-c298-power-amplifier
If you only hear it when putting the ear on the case, why is it frustrating? Because you know it is there?
Essentially. I can buy a SMPS off of amazon for a few pennies that is dead silent but a company like NAD can't implement one? It does not bode well for the rest of the implementation of the amplifier.
Wow. Can you please tell me which dead silent SMPS you can find on amazon for a few pennies and that can output more than 1KW?
You got me. I wouldn't buy on Amazon due to counterfeits. Looks like a 600w Meanwell on mouser runs for $80 which is less that 5% of the retail price of the C298. Pennies relative to the retail price of the device. I really gotta wonder what the BoM looks like on these.
Why is the C298 rated at 800w on the back of the unit? I thought class D was supposed to be very efficient.
Also, I noticed that at low volumes my c298 gets warm.
Why is the C298 rated at 800w on the back of the unit? I thought class D was supposed to be very efficient.
Also, I noticed that at low volumes my c298 gets warm.
Well, peaks can deliver at 1kw, so the SMPS must deliver that as well. The C298 contains also class AB circuitry with a generous bias (the gain stage before the power modules) and other electronics. That it gets warm is to be expected. I do not think it gets hot, am I correct?
All PSUs vibrate - real dead silent is impossible. I am sure also a good meanwell occasionally chirps…
Nice, dude throws the c298 into an $800k system with Wilson loudspeakers and it performs like a champ. I think I'll hold on to this amp for a while.
Yeas but it was a subjective evaluation! It does not count! ;-)
pogo
Major Contributor
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The real world can be so beautiful when an amplifier with a high damping factor leads the speakers and not the other way around.
roffe
Member
Picked up a c298 yesterday. No noise from the inside, no audible hiss from speakers, firmware 1.8. Sounds great so far. Bass is noticeably improved compared to Naim Atom and Accuphase E-202. Speakers are Klipsch Forte III.
wgb113
Active Member
The mixed experiences users have had with this and the companion C658 keep bumping the pairing down my shortlist. I’ve been a big fan of NAD since I bought by first integrated, a C340, back in the 90s (still have it). It’s to the point where I’m starting to lean towards the M33 all-in-one.
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It would be interesting to see a direct comparison between the C658 + C298 combo and the M33.
A Dutch audio site just reviewed the C298 and it got high praise. But they claim that although the C658 + C298 combo is very good it is not in the same league as the M33. According to the measurements of the C658 and the M33 here on ASR that makes sense. Also from a sales point of view from NAD there has to be a difference to justify the € 1800,- in price difference (here in the Netherlands).
A Dutch audio site just reviewed the C298 and it got high praise. But they claim that although the C658 + C298 combo is very good it is not in the same league as the M33. According to the measurements of the C658 and the M33 here on ASR that makes sense. Also from a sales point of view from NAD there has to be a difference to justify the € 1800,- in price difference (here in the Netherlands).
Are you serious? The "class AB circuitry with a generous bias (the gain stage before the power modules)" running hot?? This sounds highly improbable. Even the complete, smaller class AB amplifiers like 2x50W do not tend to run hot, rather something like ambient temperature. And in case of NAD, if anything like class AB driver is there, which I doubt, it would not deliver much power. Your explanation does not make any sense to me.
For the C658 yes, but the C298 measures with lower noise than the M33 power stage, probably due to presence of extra noise sources in the M33 chassis since the amp modules are the same. So what about a MiniDSP SHD paired with the C298? Better DAC/preamp and power stage than M33 for much lower cost, more flexible because it's separates and has user configurable DSP in addition to DIRAC, probably a worse streamer UI but that's what iPad's are for.
wgb113
Active Member
I’ve read here on ASR that some using the SHD as a preamp are having issues with low output levels. At this point I’m ready to look for something dead simple like an input selector with gain.
C 298 fixed gain is 28.6dB and IHF dynamic power into 8Ohms is 260W. So RMS input voltage to hit max dynamic power is sqrt(260 * 8) / 10**(28.6/20) = 1.7V. Even the unbalanced outputs of the SHD with max 2V RMS can drive the C 298 to its max dynamic power. It may be an issue with lower gain amps like the Purifi reference board, but not the C 298.
wgb113
Active Member
I thought I read that it was due to Dirac needing headroom and lowering output levels.
nothingman
Senior Member
I think I’m responsible for some of this thinking, but only because it’s what I read from people more knowledgeable than me when I first got my SHD, and because miniDSP’s mention of the -10db Dirac headroom thing in the manual is unclear.
Bottom line, after discussing this with Deer Creek Audio and my own testing: the SHD has plenty of output voltage for any power amp and it won’t clip unless you push the analog section past its 4V max output, and no one’s doing that with standard power amp sensitivity ratings, and none of it has to do with Dirac per se.
This is easy to monitor with the output section of SHD’s desktop software. Dirac operates in the 32bit floating point digital domain and it can comfortably boost frequencies without us worrying about leaving it a magical 10db of headroom on the master volume (or elsewhere on the I/O matrix). You are not going to clip in the digital domain, and if you somehow do, it would be very obvious at any SPL.
You can clip the SHD at the analog ouputs, but again, you’d have to push more than 4V out of the balanced outputs which would be out of the question on a typical 26-29db gain amp. And that doesn’t really have anything to do with Dirac. The digital signal hits the DAC with all of your Dirac/PEQ/crossover settings safely included, so from there all you have to do is watch the desktop’s output meter on a given channel which is a representation of the analog domain.
On something like the C298 with variable gain, if you did drop the gain all the way to the bottom you might clip the SHD’s analog output trying to deliver enough signal into what’s become a brick wall, but again, keep an eye on the output meters to properly set the C298’s gain.
This was a good reminder for me to make some edits and a clarifying post on the SHD thread.
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