NAD C298 Class D power amplifier impressions
Discussion
paralla said:
We recently got a new hand knotted rug, it’s 270cm x 380cm x 2cm Chinese Silk & New Zealand Wool, it weighs 64kg and covers an engineered oak floor.
Once it was in place I did a full Audissey setup of the AV amp because the rug was sure to have changed the acoustic properties of the room.
Very nice pad Once it was in place I did a full Audissey setup of the AV amp because the rug was sure to have changed the acoustic properties of the room.
I am guessing small children are not present? lol
legzr1 said:
One thing to remember is that some stereo amps which are then bridged don’t like to drive low impedance speakers.
Some nominally rated 4 ohm speakers can dip to half of that at bass frequencies.
True, but in this case its the same amp being asked to drive the same speakers in stereo mode with a single amp. It may or may not be happy, but two of them bridged will still drive them better than a single one in stereo. Some nominally rated 4 ohm speakers can dip to half of that at bass frequencies.
Whether it solves the OP's issue or not however, remains to be tested....
AdamV12V said:
These days theres a lot to be said for say a set of KEF LS60 wireless active speakers, where a single manufacture has paired up amps and speakers into a single purchase piece of tech. They pair them to precisely perform well with each other, within the limit of the budget they set to sell the units for. Being wireless they integrate directly with a phone, tv or steamer or service such as roon. They have a lot of appeal, which is why they sell well, but ultimately if you truely want to get the very best sound traditional hifi is still the way to go, but the gap closes every year.
Over the years I've had everything from LP12's, to tri-amped, bi-amped... I gradually moved into streaming and abandoned both vinyl and CD - despite have some pretty high end equipment. I have a vast collection of vinyl and CD's which is just too unruly to manage.As Harry says, I now have the LS60's. They connect directly to Qobuz (where I get most of my music), Spotify (where I get a tiny bit of my music) and they are managed by Roon with a very advanced DSP and Convolution filter tech. I don't stream to them from any device. I have a fast broadband and everything is hard-wired to the router.
3 matched amplifiers per speaker, 6 drive units per cabinet and 1400 watts.
Unfortunately due to tinnitus I no longer have the critical ear I once did - but I'd say they deliver way above their fairly lumpy purchase price. I'd say you would have to spend a considerably higher amount to get close. Matched Class A, B and D amplifiers and the 'single source' drive positioning gives pin point imagery.
Are they for everyone? No. There's a lot of pleasure from building a system.
OutInTheShed said:
I think a lot of 'audiophile nonsense' has a grain of truth in it, often taken out of context, and often extrapolated to absurd levels.
My feeling on cables and crossovers is it seems a bit potty to spend loads of time and money developing or buying a slightly better amplifier, then isolate it from the load with an inductor, add an undefined length of cable then a speaker different from the one the amp was developed for, with a bunch of reactive components between the driver coil and the cable.
It just seems far more elegant to have one power amp per driver coil.
On the subject of speaker cables - it's fair to say that quite often a heavier gauge than one would expect is required, especially with a hefty amp and 4 ohm (average) speakers. The peak currents can be quite high at higher volumes.My feeling on cables and crossovers is it seems a bit potty to spend loads of time and money developing or buying a slightly better amplifier, then isolate it from the load with an inductor, add an undefined length of cable then a speaker different from the one the amp was developed for, with a bunch of reactive components between the driver coil and the cable.
It just seems far more elegant to have one power amp per driver coil.
OutInTheShed said:
Also it potentially means less power amps can be used, if the peak audio waveform is 10V of Bass with 10V of Treble superposed on it, you need a 20V amp instead of two 10V amps. A 20V amp is 4x the power of a 10V amp.
<snip>
You need to bear in mind that music is typically distributed in a ratio of approx. 90/10 bass / treble.<snip>
The tweeter in a typical passive speaker will only see around 10% of actual input power, the bass unit will be absorbing the remainder.
It's not uncommon for a typical passive speaker to have a bass unit rated at 100w and a tweeter rated at 10w.
This is why I see bi-amping as a bit of an extravagance - as that amp handling the top end has a very easy life, and an active crossover is a much better option here.
That's why active speakers will usually have a much lower power amp for the tweeter compared to the bass unit.
The NAD C298 can output 25A max, regardless of the impedance of the speakers connected to it when it’s in stereo mode, cross sectional area of the speaker cables should be selected with this in mind.
When it’s bridged to mono, the impedance of the single speaker (nominally 4 Ohms) connected across both channels effectively means each channel of the amp only sees half that impedance (nominally 2 Ohms) of the speaker, this drastically increases the current in the Amp and speaker voice coils which is what improves the bass authority of the speakers, even at low volumes.
Harry, a single 4 Ohm speaker powered by a bridged stereo amp is asking a lot of the amp. It would be a monster system connected to your SF’s so I very much doubt clipping would be an issue (there’s protection in the amp against it anyway) but the amps might run pretty warm if you run them bridged so make sure they have plenty of ventilation. Don’t stack one on top of the other without a shelf in between them.
Having read the Amp manual, scratch all advice above to bridge two C298’s and run as monoblocks into a 4 Ohm speaker.
“ 11 BRIDGE MODE
The C 298 amplifier can be configured to be MONO (Bridge Mode), more than doubling its output power. This way, the C 298 can be used as part of a high power stereo or home-theatre system, by connecting additional power amplifiers.
• In BRIDGED MODE (switch at ON (MONO) setting), the C 298 will
produce approximately 620W into an 8 ohm loudspeaker. In this mode, the amplifier sections will react as though the speaker impedance
has been halved. Low impedance speakers (under 8 ohms) are not recommended when using Bridge Mode as these may cause the amplifier’s thermal cut-out to operate if played at high levels.”
It might (probably would) work great but I don’t want to recommend going against the manufacturer’s recommendation.
If you get another one, bi-amp the speakers rather than power one speaker from one amp.
When it’s bridged to mono, the impedance of the single speaker (nominally 4 Ohms) connected across both channels effectively means each channel of the amp only sees half that impedance (nominally 2 Ohms) of the speaker, this drastically increases the current in the Amp and speaker voice coils which is what improves the bass authority of the speakers, even at low volumes.
Harry, a single 4 Ohm speaker powered by a bridged stereo amp is asking a lot of the amp. It would be a monster system connected to your SF’s so I very much doubt clipping would be an issue (there’s protection in the amp against it anyway) but the amps might run pretty warm if you run them bridged so make sure they have plenty of ventilation. Don’t stack one on top of the other without a shelf in between them.
Having read the Amp manual, scratch all advice above to bridge two C298’s and run as monoblocks into a 4 Ohm speaker.
“ 11 BRIDGE MODE
The C 298 amplifier can be configured to be MONO (Bridge Mode), more than doubling its output power. This way, the C 298 can be used as part of a high power stereo or home-theatre system, by connecting additional power amplifiers.
• In BRIDGED MODE (switch at ON (MONO) setting), the C 298 will
produce approximately 620W into an 8 ohm loudspeaker. In this mode, the amplifier sections will react as though the speaker impedance
has been halved. Low impedance speakers (under 8 ohms) are not recommended when using Bridge Mode as these may cause the amplifier’s thermal cut-out to operate if played at high levels.”
It might (probably would) work great but I don’t want to recommend going against the manufacturer’s recommendation.
If you get another one, bi-amp the speakers rather than power one speaker from one amp.
Edited by paralla on Friday 7th April 11:18
paralla said:
The NAD C298 can output 25A max, regardless of the impedance of the speakers connected to it when it’s in stereo mode, cross sectional area of the speaker cables should be selected with this in mind.
When it’s bridged to mono, the impedance of the single speaker (nominally 4 Ohms) connected across both channels effectively means each channel of the amp only sees half that impedance (nominally 2 Ohms) of the speaker, this drastically increases the current in the Amp and speaker voice coils which is what improves the bass authority of the speakers, even at low volumes.
Harry, a single 4 Ohm speaker powered by a bridged stereo amp is asking a lot of the amp. It would be a monster system connected to your SF’s so I very much doubt clipping would be an issue (there’s protection in the amp against it anyway) but the amps might run pretty warm if you run them bridged so make sure they have plenty of ventilation. Don’t stack one on top of the other without a shelf in between them.
Having read the Amp manual, scratch all advice above to bridge two C298’s and run as monoblocks into a 4 Ohm speaker.
“ 11 BRIDGE MODE
The C 298 amplifier can be configured to be MONO (Bridge Mode), more than doubling its output power. This way, the C 298 can be used as part of a high power stereo or home-theatre system, by connecting additional power amplifiers.
• In BRIDGED MODE (switch at ON (MONO) setting), the C 298 will
produce approximately 620W into an 8 ohm loudspeaker. In this mode, the amplifier sections will react as though the speaker impedance
has been halved. Low impedance speakers (under 8 ohms) are not recommended when using Bridge Mode as these may cause the amplifier’s thermal cut-out to operate if played at high levels.”
It might (probably would) work great but I don’t want to recommend going against the manufacturer’s recommendation.
If you get another one, bi-amp the speakers rather than power one speaker from one amp.
Good post and the reason I suggested caution with bridged amp,offers into a 4 ohm load.When it’s bridged to mono, the impedance of the single speaker (nominally 4 Ohms) connected across both channels effectively means each channel of the amp only sees half that impedance (nominally 2 Ohms) of the speaker, this drastically increases the current in the Amp and speaker voice coils which is what improves the bass authority of the speakers, even at low volumes.
Harry, a single 4 Ohm speaker powered by a bridged stereo amp is asking a lot of the amp. It would be a monster system connected to your SF’s so I very much doubt clipping would be an issue (there’s protection in the amp against it anyway) but the amps might run pretty warm if you run them bridged so make sure they have plenty of ventilation. Don’t stack one on top of the other without a shelf in between them.
Having read the Amp manual, scratch all advice above to bridge two C298’s and run as monoblocks into a 4 Ohm speaker.
“ 11 BRIDGE MODE
The C 298 amplifier can be configured to be MONO (Bridge Mode), more than doubling its output power. This way, the C 298 can be used as part of a high power stereo or home-theatre system, by connecting additional power amplifiers.
• In BRIDGED MODE (switch at ON (MONO) setting), the C 298 will
produce approximately 620W into an 8 ohm loudspeaker. In this mode, the amplifier sections will react as though the speaker impedance
has been halved. Low impedance speakers (under 8 ohms) are not recommended when using Bridge Mode as these may cause the amplifier’s thermal cut-out to operate if played at high levels.”
It might (probably would) work great but I don’t want to recommend going against the manufacturer’s recommendation.
If you get another one, bi-amp the speakers rather than power one speaker from one amp.
Edited by paralla on Friday 7th April 11:18
legzr1 said:
paralla said:
The NAD C298 can output 25A max, regardless of the impedance of the speakers connected to it when it’s in stereo mode, cross sectional area of the speaker cables should be selected with this in mind.
When it’s bridged to mono, the impedance of the single speaker (nominally 4 Ohms) connected across both channels effectively means each channel of the amp only sees half that impedance (nominally 2 Ohms) of the speaker, this drastically increases the current in the Amp and speaker voice coils which is what improves the bass authority of the speakers, even at low volumes.
Harry, a single 4 Ohm speaker powered by a bridged stereo amp is asking a lot of the amp. It would be a monster system connected to your SF’s so I very much doubt clipping would be an issue (there’s protection in the amp against it anyway) but the amps might run pretty warm if you run them bridged so make sure they have plenty of ventilation. Don’t stack one on top of the other without a shelf in between them.
Having read the Amp manual, scratch all advice above to bridge two C298’s and run as monoblocks into a 4 Ohm speaker.
“ 11 BRIDGE MODE
The C 298 amplifier can be configured to be MONO (Bridge Mode), more than doubling its output power. This way, the C 298 can be used as part of a high power stereo or home-theatre system, by connecting additional power amplifiers.
• In BRIDGED MODE (switch at ON (MONO) setting), the C 298 will
produce approximately 620W into an 8 ohm loudspeaker. In this mode, the amplifier sections will react as though the speaker impedance
has been halved. Low impedance speakers (under 8 ohms) are not recommended when using Bridge Mode as these may cause the amplifier’s thermal cut-out to operate if played at high levels.”
It might (probably would) work great but I don’t want to recommend going against the manufacturer’s recommendation.
If you get another one, bi-amp the speakers rather than power one speaker from one amp.
Good post and the reason I suggested caution with bridged amp,offers into a 4 ohm load.When it’s bridged to mono, the impedance of the single speaker (nominally 4 Ohms) connected across both channels effectively means each channel of the amp only sees half that impedance (nominally 2 Ohms) of the speaker, this drastically increases the current in the Amp and speaker voice coils which is what improves the bass authority of the speakers, even at low volumes.
Harry, a single 4 Ohm speaker powered by a bridged stereo amp is asking a lot of the amp. It would be a monster system connected to your SF’s so I very much doubt clipping would be an issue (there’s protection in the amp against it anyway) but the amps might run pretty warm if you run them bridged so make sure they have plenty of ventilation. Don’t stack one on top of the other without a shelf in between them.
Having read the Amp manual, scratch all advice above to bridge two C298’s and run as monoblocks into a 4 Ohm speaker.
“ 11 BRIDGE MODE
The C 298 amplifier can be configured to be MONO (Bridge Mode), more than doubling its output power. This way, the C 298 can be used as part of a high power stereo or home-theatre system, by connecting additional power amplifiers.
• In BRIDGED MODE (switch at ON (MONO) setting), the C 298 will
produce approximately 620W into an 8 ohm loudspeaker. In this mode, the amplifier sections will react as though the speaker impedance
has been halved. Low impedance speakers (under 8 ohms) are not recommended when using Bridge Mode as these may cause the amplifier’s thermal cut-out to operate if played at high levels.”
It might (probably would) work great but I don’t want to recommend going against the manufacturer’s recommendation.
If you get another one, bi-amp the speakers rather than power one speaker from one amp.
Edited by paralla on Friday 7th April 11:18
Harry Flashman said:
Stop it!!
You have a fantastic pair of speakers and a totally respectable amplifier that needs no apologies. With Dirac room correction, small sub and the adjustability in your system it’s no surprise you are happy with it.Stop thinking about the system and enjoy the music for a few weeks at least.
If the itch still needs scratching upping the power is probably the next logical step. If I were in your shoes I’d see if I could blag an extended test (or sale and return) of one of these at 19kg. It uses a switch mode power supply like your NAD.
https://emotiva.com/collections/amps/products/xpa-...
A similar high power stereo power amp with a conventional toroidal transformer power supply is going to be heavy/massive and will save you lighting the log burner.
Thanks paralla!
Like I needed yet another expensive hobby...
But you're right. Now I'm going to play with what I have, the room and the DSP. And carry on rediscovering my deep love of music.
One thing that having a half decent setup has given me - I am chasing production quality as much as genre. And this has led me to stuff I have never listened to before, and I like that a lot.
Like I needed yet another expensive hobby...
But you're right. Now I'm going to play with what I have, the room and the DSP. And carry on rediscovering my deep love of music.
One thing that having a half decent setup has given me - I am chasing production quality as much as genre. And this has led me to stuff I have never listened to before, and I like that a lot.
Harry Flashman said:
Thanks paralla!
Like I needed yet another expensive hobby...
But you're right. Now I'm going to play with what I have, the room and the DSP. And carry on rediscovering my deep love of music.
One thing that having a half decent setup has given me - I am chasing production quality as much as genre. And this has led me to stuff I have never listened to before, and I like that a lot.
Amen to that!Like I needed yet another expensive hobby...
But you're right. Now I'm going to play with what I have, the room and the DSP. And carry on rediscovering my deep love of music.
One thing that having a half decent setup has given me - I am chasing production quality as much as genre. And this has led me to stuff I have never listened to before, and I like that a lot.
My range of genres has gotten a lot wider since getting something that sounds decent
Harry, it may be worth having a chat with Terry Ellis/Pursuit Perfect System about a Dirac calibration (he offers in person or remote calibration - he has a YT channel doing kit reviews and comes across as a genuinely knowledgeable and likeable guy, and probably a lot cheaper than buying new amps etc!) https://www.diraclivecalibration.com/
The tap of a plectrum on a guitar body or the hum of a valve guitar amp in a live recording that you are hearing for the first time despite him being one of your all time favourite artists. Jeff Buckley, Live at Sin-é - Mojo Pin
https://open.spotify.com/track/3rANzj4jmgcaKKAxVMk...
The subtle intake of breath of a female vocal. Nina Simone, Four Women: Nina Simone The Phillips Recordings. I Loves You Porgie - Live at Carnegie Hall 1964
https://open.spotify.com/track/2VwFNJfJtqG5qAIWZOo...
Being moved by the power and scale of an orchestral strings section mashed up with some late 90’s trip hop turned up to eleven. Portishead - All Mine
https://open.spotify.com/track/785Qya5mtMUwBQtuypV...
Feeling the kick of a rocking bass line as much as hearing it. Harry Nelson - Jump Into The Fire
https://open.spotify.com/track/3hgHrfMdtnLtH54HYTd...
Realising that the guitar lick in a track is a thing of beauty (I was too young at the time to fully appreciate it) Pearl Jam - Go
https://open.spotify.com/track/7HB80cV49jisD0LepcG...
That’s what it’s about.
https://open.spotify.com/track/3rANzj4jmgcaKKAxVMk...
The subtle intake of breath of a female vocal. Nina Simone, Four Women: Nina Simone The Phillips Recordings. I Loves You Porgie - Live at Carnegie Hall 1964
https://open.spotify.com/track/2VwFNJfJtqG5qAIWZOo...
Being moved by the power and scale of an orchestral strings section mashed up with some late 90’s trip hop turned up to eleven. Portishead - All Mine
https://open.spotify.com/track/785Qya5mtMUwBQtuypV...
Feeling the kick of a rocking bass line as much as hearing it. Harry Nelson - Jump Into The Fire
https://open.spotify.com/track/3hgHrfMdtnLtH54HYTd...
Realising that the guitar lick in a track is a thing of beauty (I was too young at the time to fully appreciate it) Pearl Jam - Go
https://open.spotify.com/track/7HB80cV49jisD0LepcG...
That’s what it’s about.
paralla said:
The tap of a plectrum on a guitar body or the hum of a valve guitar amp in a live recording that you are hearing for the first time despite him being one of your all time favourite artists. Jeff Buckley, Live at Sin-é - Mojo Pin
https://open.spotify.com/track/3rANzj4jmgcaKKAxVMk...
The subtle intake of breath of a female vocal. Nina Simone, Four Women: Nina Simone The Phillips Recordings. I Loves You Porgie - Live at Carnegie Hall 1964
https://open.spotify.com/track/2VwFNJfJtqG5qAIWZOo...
Being moved by the power and scale of an orchestral strings section mashed up with some late 90’s trip hop turned up to eleven. Portishead - All Mine
https://open.spotify.com/track/785Qya5mtMUwBQtuypV...
Feeling the kick of a rocking bass line as much as hearing it. Harry Nelson - Jump Into The Fire
https://open.spotify.com/track/3hgHrfMdtnLtH54HYTd...
Realising that the guitar lick in a track is a thing of beauty (I was too young at the time to fully appreciate it) Pearl Jam - Go
https://open.spotify.com/track/7HB80cV49jisD0LepcG...
That’s what it’s about.
Get yourself into this thread, in case you aren't already!https://open.spotify.com/track/3rANzj4jmgcaKKAxVMk...
The subtle intake of breath of a female vocal. Nina Simone, Four Women: Nina Simone The Phillips Recordings. I Loves You Porgie - Live at Carnegie Hall 1964
https://open.spotify.com/track/2VwFNJfJtqG5qAIWZOo...
Being moved by the power and scale of an orchestral strings section mashed up with some late 90’s trip hop turned up to eleven. Portishead - All Mine
https://open.spotify.com/track/785Qya5mtMUwBQtuypV...
Feeling the kick of a rocking bass line as much as hearing it. Harry Nelson - Jump Into The Fire
https://open.spotify.com/track/3hgHrfMdtnLtH54HYTd...
Realising that the guitar lick in a track is a thing of beauty (I was too young at the time to fully appreciate it) Pearl Jam - Go
https://open.spotify.com/track/7HB80cV49jisD0LepcG...
That’s what it’s about.
https://www.pistonheads.com/gassing/topic.asp?h=0&...
Harry Flashman said:
Get yourself into this thread, in case you aren't already!
https://www.pistonheads.com/gassing/topic.asp?h=0&...
Lucky it’s a long weekend, that’s going to take some going through.https://www.pistonheads.com/gassing/topic.asp?h=0&...
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