I own the C 275BEE, along the C165Bee preamp, great pairing..

@ripewave

3 ай бұрын

I bet is sounds real clean. -Jon

@thethirdman225

2 ай бұрын

Top of my list... if I could find it.

The weights you listed are the shipping weights. The m23 weighs 21.6lbs

On the C268 , what exactly does that input level knob do? Is it possible to kinda control the output?

With class-D you really have to pay close attention to how it performs at high frequencies, class-D is pulsed power, which then needs an inductor stage to smooth it, inductors naturally impede high frequency switching (they resist change in the electromagnetic field). So it’s an inherent technical challenge to put through allot of current at higher frequencies with class-D. For the consumer, they need to pay close attention to the impedance of their tweeters, if they’re low impedance 4ohm tweeters, the class-D may not be able to deliver the current they draw with grace and fidelity. Gallium nitride class-D has faster switching, and needs less smoothing, so a gallium nitride class-D amp with a gentler filter will probably have less output impedance at higher frequencies. Each generation of class D has improved upon the high frequency performance with various designs, but it still remains the weakest link in the bandwidth. See if you can get the technical papers on the module, for instance if you look at ICEpower’s 1200as-2 pdf, you can see the rising output impedance relative to frequency in some of their graphs. Which has to be kept in context of class A, class AB, and competing class D design’s performance. Clearly many engineers feel it’s good enough to ship, but maybe it’s also cheaper and has so much low frequency performance that the high frequency hearing-loss region has been compromised for an aging hifi demographic, or a customer bass that shops on advertised watts which class-D excels at. Myself included.

@connorduke4619

Жыл бұрын

Excellent analysis. Is it possible to combine Purifi Eigentakt with Galilum nitride, or is it really one or the other?

@SwirlingDragonMist

Жыл бұрын

@@connorduke4619 I don’t know, I’m really at the edge of my current knowledge with my above statement. My sense is that it’s not either or. I know even the same class of amplifier technology can have allot of differences in how the design is implemented.

@truwarrior22

5 ай бұрын

If you can’t hear above 12-14khz, does it matter?

@SwirlingDragonMist

5 ай бұрын

@@truwarrior22 I suppose it my not, as that is where class D begins to roll off it’s performance (typically) but being so close to frequencies you can hear, the potential for audible “intermodulation distortion” created from inaudible waves and audible waves could exist.

The blue connectors represent and unbalanced design negotiate. Meaning there is no negative charge. I know this from NAD support as I have an M28 and I needed and active ground for my Polk Legend speakers 😭

@ripewave

Жыл бұрын

This is real helpful knowledge - thanks so much. I need to better understand the negative grounding and how some speakers like the Legends with SDA technology are impacted and why NAD has taken this route. -Jon

@Wozzaatwozza

Жыл бұрын

@@ripewave I don’t claim to fully understand it. Apparently from what I was advised is Class D isn’t a fully balanced design (not to be confused with balanced connectors), but in cases like the Emotiva XPA DR series they are balanced due to using two amp modules powering both the positive and negotiate channels. Likewise a minority of Class A/B amps are balanced differential design like ATI, Outlaw, Monoprice, to name a few.

@ripewave

Жыл бұрын

I feel there isn’t enough clear information out there about the value a fully differential design delivers. I read feedback for some who say that is a wasted effort with no appreciable improvement while other claim there is a difference. I also what to understand how some speakers, like the Polk legend SDA models need grounding a certain way to work correctly.-Jon

@Wozzaatwozza

Жыл бұрын

@@ripewave I agree. The Legend 800’s need full balanced design to power the SDA feature

@gracenotes5379

Жыл бұрын

Actually, the meaning of the Blue connector instead of black is that the negative speaker terminals must never be connected to ground, nor to each other, nor to any common ground device. This is not an issue when connecting to purely passive speakers in the ordinary way, but would cause a major issue if you tried to send audio to a powered sub-woofer using the speaker wires. I'm not sure which Polk Legend speakers you had, but the SDA interconnect cable on the some Polk models would violate the rules for keeping the outputs isolated from each other.

Glad you brought it to my attention that most of these amps are class D, i'll pass.

@ripewave

Жыл бұрын

Newer Class D amplifier reviews often conclude that they are “as good as” Class AB. Why get something that is “as good as” when you can have a real Class AB amplifier? The answer is when lower weight and heat are important criteria for you. What may be turning things for me is test reports are beginning to show amplifiers with the Purifi module outperforming sonically class AB. However, I am finding the cost per channel of amplifiers with those modules more expensive at this time. -Jon