To upgrade or not to upgrade, that is the question.

[Ashley Salmond]

I have a Anthem MCA 225 gen1 amplifier that has a SNR of 120, 300 damping factor and Thd .0010%. the Anthem specs are past the audiable .Looking at the Amplifier rating chart I see the new Purifi D class amps have made significant improvement to the point that they surpass leading brands and go toe toe with the Benchmark. These improvements are way past audiable. And there lies the question, if it's past audiable are you actually getting improvement in the sound by going even further past the audiable range or are you simply wasting money. Is there an improvement in the frequency response or has this been put thru a blind test. I would appreciate anyone's experience in this.

 

[rwortman]

There is more to the sound of an amplifier than those specifications you quoted. You really have to connect one to your speakers to know for sure. You might even find the class D amp an audible deterioration in sound quality.

 

[voodooless]

There is more to the sound of an amplifier than those specifications you quoted.

What specifically are you referring to?

You might even find the class D amp an audible deterioration in sound quality.

Do all class D amps have the same sound signature?

 

[symphara]

Unless you need more power, or have a specific problem (like noise), it's unlikely that you can improve your system by changing this amplifier.

If you feel the need to spend some cash on your audio system, why not invest in some quality of life stuff, like a nice streamer or a NAS where you can keep your music.

 

[Beave]

I have a Anthem MCA 225 gen1 amplifier that has a SNR of 120, 300 damping factor and Thd .0010%. the Anthem specs are past the audiable .Looking at the Amplifier rating chart I see the new Purifi D class amps have made significant improvement to the point that they surpass leading brands and go toe toe with the Benchmark. These improvements are way past audiable. And there lies the question, if it's past audiable are you actually getting improvement in the sound by going even further past the audiable range or are you simply wasting money. Is there an improvement in the frequency response or has this been put thru a blind test. I would appreciate anyone's experience in this.

Are those specs independently measured & verified? If so, and the amp is in good working condition, then the way you phrased your question contains the answer: Once inaudible, going to "more" inaudible will still just be inaudible.

The biggest difference in competently designed amplifiers is power output into varying loads. Most will sound the same when operating in their comfort zone, but the comfort zone can vary considerably from one amp to another (ie, some can output far more power into low impedance loads than others, or maintain their output into highly capacitive or inductive loads compared to others).

 

[Deleted member 19122]

You won't hear any differences given equal wpc.Only thing that you'd gain from Class D is energy saving and cooler running(things that matter in smaller rooms) and probably longer lifespan given the much cooler operating temps.

 

[rwortman]

What specifically are you referring to?


Do all class D amps have the same sound signature?

I don’t know. To answer that question, I would have to listen to them all.

I don’t think the high spec class D amp will necessarily sound better or worse. It depends. No reviewer I am aware of measures amps while they are driving a speaker. A speaker is not only a complex passive load, it is an active one, sending voltage back to amplifier. How the feedback circuit deals with this is of interest. I am sure some amplifier designers do look at this, but still not with every speaker. That’s why I don’t think you can know how an amp will sound driving your speakers until you take it home and try it.

 

[Ashley Salmond]

Unless you need more power, or have a specific problem (like noise), it's unlikely that you can improve your system by changing this amplifier.
,
If you feel the need to spend some cash on your audio system, why not invest in some quality of life stuff, like a nice streamer or a NAS where you can keep your music.

Thank you Symphara , so would would say once you are past audiable,-115db then you have the point of deminished return. Or in Audioscience Amplifier rating chart the Blue Zone.

 

[voodooless]

I don’t know. To answer that question, I would have to listen to them all.

Then why bring the class of the amplifier up? Isn’t this true for any amp then?

I don’t think the high spec class D amp will necessarily sound better or worse. It depends. No reviewer I am aware of measures amps while they are driving a speaker. A speaker is not only a complex passive load, it is an active one, sending voltage back to amplifier.

A load mimicking speaker impedance, like Amir uses will do just that. Capacitors and inductors can store and release energy.

How the feedback circuit deals with this is of interest. I am sure some amplifier designers do look at this, but still not with every speaker.

The damping factor tells you how well an amplifier deals with these things. Some reading:

Amplifier Output Impedance (Damping Factor) and Speakers

This is a reprint of an article written ca. 2011-2012. I've been meaning to rewrite and update it, but Life and Work keeps getting in the way, so I am reposting the original as-is. Take it for what it's worth, an introductory take on one of the potential causes for differences in sound among...

www.audiosciencereview.com

That’s why I don’t think you can know how an amp will sound driving your speakers until you take it home and try it.

Without a controlled test I presume…

 

[symphara]

Thank you Symphara , so would would say once you are past audiable,-115db then you have the point of deminished return. Or in Audioscience Amplifier rating chart the Blue Zone.

I don't know if the MCA 225 would make the blue zone but I heard it with big speakers (Revel F208, Pradigm Persona 5F I think) playing very loudly and I thought it was a competent amp. There was no noise and plenty of power.

 

[delta76]

I have a Anthem MCA 225 gen1 amplifier that has a SNR of 120, 300 damping factor and Thd .0010%. the Anthem specs are past the audiable .Looking at the Amplifier rating chart I see the new Purifi D class amps have made significant improvement to the point that they surpass leading brands and go toe toe with the Benchmark. These improvements are way past audiable. And there lies the question, if it's past audiable are you actually getting improvement in the sound by going even further past the audiable range or are you simply wasting money. Is there an improvement in the frequency response or has this been put thru a blind test. I would appreciate anyone's experience in this.

there is a difference between specs and measured performance. Without measuring your amp, we don't know how good it is actually (you can chat with Amir and send yours to him btw)
A generic advice is to spend more money on your speakers and room treatment, than upgrading your amp.

 

[Ashley Salmond]

there is a difference between specs and measured performance. Without measuring your amp, we don't know how good it is actually (you can chat with Amir and send yours to him btw)
A generic advice is to spend more money on your speakers and room treatment, than upgrading your amp.

That sounds like a good idea delta76:

 

[Ashley Salmond]

There is more to the sound of an amplifier than those specifications you quoted. You really have to connect one to your speakers to know for sure. You might even find the class D amp an audible deterioration in sound quality.

Thank your rwortman ,yes it's the only way to truely find out.

 

[Spkrdctr]

The quick answer is that once you are in the inaudible range then you are wasting money by going after extreme specs. If it is not audible, it is not audible.

 

[Joe Smith]

IMO most critical thing is having a good power match between amp and speakers. Having enough power headroom to handle transients, depending on the music you listen to and the volume you play at. If your current amp has no problems, good specs and decent headroom for your speakers - you're good.

 

[rwortman]

Then why bring the class of the amplifier up? Isn’t this true for any amp then?

Because that’s what the OP asked about?

A load mimicking speaker impedance, like Amir uses will do just that. Capacitors and inductors can store and release energy.

No, it doesn’t, because speaker drivers don’t store and release energy in the same way that coils and caps do. Additionally, Amir uses resistors, not complex loads.

The damping factor tells you how well an amplifier deals with these things

Not completely. Damping factor is a simple resistive model, and it changes with frequency. It doesn’t tell us how the feedback loop will respond to a back EMF that is out of phase with the original signal. The output impedance is not purely resistive. Part of it has a phase angle that also changes with frequency. I think the situation of driving a box full of motors on the other side of pretty complicated crossover networks is not that simple. I think good amp designers know this. It may also explain why some people claim to not like sound of high NFB designs, that btw, have very low output impedance.

 

[voodooless]

Because that’s what the OP asked about?

No, he asked for the specific amplifier, not all class d amps

No, it doesn’t, because speaker drivers don’t store and release energy in the same way that coils and caps do.

Except for that they do. In fact you can construct an equivalence model of a speaker with passive components:

If you want, you can make it more complex and simulate all kinds of box alignment as well.

Additionally, Amir uses resistors, not complex loads.

Maybe not, but others have, as I linked. No magic to be found there. Damping factor predicts just fine what happens here. Sure it’s not a single number, but changes over frequency. So what?

I think good amp designers know this. It may also explain why some people claim to not like sound of high NFB designs, that btw, have very low output impedance.

Ah, so amps react better to back EMF without a mechanism for doing so?

 

[Beave]

No, it doesn’t, because speaker drivers don’t store and release energy in the same way that coils and caps do. Additionally, Amir uses resistors, not complex loads.

Not completely. Damping factor is a simple resistive model, and it changes with frequency. It doesn’t tell us how the feedback loop will respond to a back EMF that is out of phase with the original signal. The output impedance is not purely resistive. Part of it has a phase angle that also changes with frequency. I think the situation of driving a box full of motors on the other side of pretty complicated crossover networks is not that simple. I think good amp designers know this. It may also explain why some people claim to not like sound of high NFB designs, that btw, have very low output impedance.

Has anybody ever shown the back EMF to be an actual audible problem and not just a theoretical one?

 

[rwortman]

Except for that they do. In fact you can construct an equivalence model of a speaker with passive components:

That might be approximate, but it‘s not equivalent.

Damping factor predicts just fine what happens here. Sure it’s not a single number, but changes over frequency.

An impedance ratio that assumes a phase angle of 0 for both numbers does not.

Ah, so amps react better to back EMF without a mechanism for doing so

No, they react differently depending on the method of doing so.

Conventional wisdom in here says that all amps with test bench noise and distortion below X and a damping factor above Y will all sound the same driving every speaker made unless it is driven into clipping. Millions of people whose experience suggests otherwise are being fooled by their eyes or by level changes. I am not so sure.

 

[voodooless]

Millions of people whose experience suggests otherwise are being fooled by their eyes or by level changes. I am not so sure.

Well, billions of people experience all kinds of things that can’t all be true, so that isn’t really a convincing argument. Controlled testing shows a totally different story.