Difference between amplifiers...

Lyngdorf works like switch mode types? What exactly is that. Digital 1.0. Or on and off? Sorry from quick read it’s how the transistor works in an an digital amplifier.

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Then perhaps you can explain why even 20 watts Class A amplifier are perhaps rated on paper like 100 Watts Class AB amplifiers.
Sorry about having to complete the rest of your post, need a new Ipad. If the amplifier is biased full on all the time it will sound louder.
 
I think I wrote the whole post. Anyway from my understanding A Classe amplifier operates with the transistors on all the time. Classe AB amplifier works a bit different. The transistors are on and off. And if I’m not mistaken Classe D works like switch mode transistors before the sound reaches the output stage. Sorry by bad with the capacitors with my lousy explanation of Classe A amplifiers.
 
Every amplifier have their flaws. In my own experience it’s best to get the correct match between the correct speakers, amplifiers even if it’s Classe A, Class AB, Class D.
 
Then perhaps you can explain why even 20 watts Class A amplifier are perhaps rated on paper like 100 watts.?
Because a Class A amp is always running current through its output devices, it's always consuming power even when completely silent. A class A amp rated at 20 watts when silent can easily be consuming as much power as a class AB amp with a far higher rating playing music.

As a result, a class A amp needs a bigger power supply, including bigger capacitors. And it runs a lot hotter, as the zero-signal bias current has nowhere else to go.
 
And a Class A amplifier is not so efficient as we all know. A lot of power that could drive the speakers disappears in heat. They don’t last so long. Can’t be on all the time vs other designs. But it depends which Classe A amplifier you buy. Most Classe A amplifier are very, very expensive. So if you buy a Luxman Class A amplifier for instance I bet it could last a long time. Most Class A amplifier are very expensive.
 
Because a Class A amp is always running current through its output devices, it's always consuming power even when completely silent. A class A amp rated at 20 watts when silent can easily be consuming as much power as a class AB amp with a far higher rating playing music.

As a result, a class A amp needs a bigger power supply, including bigger capacitors. And it runs a lot hotter, as the zero-signal bias current has nowhere else to go.
Thanks my friend. I learning all the time. I’m very intrigued on getting my self a Class D amplifier because of their efficiency. But I have yet to hear a musical D amplifier. But the match I heard in store could not have been setup properly. I’ve heard good things about Lyngdorf digital amplifiers.
 
Amplifiers with big capacitors are not always a good thing. They take longer to charge than discharge, so a loud signal can start to discharge the capacitors faster than the power supply can replenish.

Switch mode power supplies are much better in this respect, as the voltage rails are re-supplied thousands of times per second, not just 50/60 per second as happens with a conventional linear power supply.

Class D switching amplifiers produce huge amounts of distortion in the extreme HF which has to be filtered out. To my ears they can sound quite cold and clinical compared to most class A/AB amplifiers, but this has nothing to do with the power supply. If this is poor, the ripple will upset the amplifier and affect the distortion and accuracy of reproduction. Class D amplifiers in particular can be horribly affected by supply ripple, as they are designed around a fixed amplitude and any change in the power supply rails may affect this.
 
Thanks.
So feedback is undesirable. When an amp is designed, is it known at that time that it will have feedback, and that it is then a matter of how it will be dealt with, current or voltage feedback?
If Lyngdorf amps do not have feedback how come they can design it out when other manufacturers seemingly cannot?
I'm not sure you're not mixing things up.

Many amps use negative feed back as part of their design, as it helps with many positive attributes, such as reduction in noise and distortion.

This is different to back emf from speakers.
 
If the amplifier design uses Op-Amps, then negative feedback is almost always required to set the gain of that stage of the amplification. If the design uses discrete transistors, it is possible to reduce or even remove negative feedback altogether, but this might cause other issues around RF stability and gain setting.

Negative feedback can mess up the high frequency response of a poorly designed amplifier - particularly if the slew rate is not as high as it might be. Good filtering of out of band signals can normally cure the issues that negative feedback creates, but reducing the number of stages of amplification is usually the best design rationale for high quality amplification.
 
Thanks guys! Learning a lot. As for the NAD M10 is that fully digital? From my understanding it’s not.
 
Many amps use negative feed back as part of their design, as it helps with many positive attributes, such as reduction in noise and distortion.

This is different to back emf from speakers.
Yes indeed. Negative feedback in the amplification stages is a debatably good thing (and critical with op-amps that essentially produce maximum gain without it). But "feedback" from speakers back into amplifiers is always a bad thing which needs to be controlled - as per talk of damping factors.
 
This site is awesome😎. You learn something all the time. Back to the NAD M10 that isn’t fully digital is it? From my understanding it’s a hybrid amplifier. So are all the new NAD amplifiers. So that means it’s both Classe AB, Classe D. So it uses push pull configuration, switch mode transistors. Correct if I’m wrong😊.
 
Apparently the new NAD series are fully digital amplifiers from my reading. Hypercore technology.
 
But "feedback" from speakers back into amplifiers is always a bad thing which needs to be controlled - as per talk of damping factors.
Yup. Back emf is a function of any driven magnetic device, so equally but of no relevance to this discussion, electric motors.

And yup, generally the higher the df, the greater control an amp has over voice coils.
 
Apparently the new NAD series are fully digital amplifiers from my reading. Hypercore technology.
I don't know, but should think not. Class D does not = digital. It's another misnomer.
 
Maybe your right. But at last they are hybrid amplifiers.
 
Maybe your right. But at last they are hybrid amplifiers.
Like many things, it depends how you look at it.
Sticking a digital to analogue converter in the signal path, even within the same case, doesn't change the fact that the amp is analogue.
 
Excuse my ignorance in the matter but, do not all amps require feedback to function correctly?
from this review: Lyngdorf Audio TDAI-2170 Fully-Digital Integrated Amplifier Review - HomeTheaterHifi.com

For starters, the internal clock used in the TDAI-2170 runs at 400kHz, not just several multiples of the oft used 20kHz (supposed upper range of human hearing), but more than an order of magnitude bigger! This combined with custom, high quality (not to mention fast) transistors nearly eliminates the biggest source of distortion, timing. They also isolate each component to limit the impact each has on the other. Because of this quality of design and build, the TDAI-2170 has NO feedback, and thus no need for a feedback loop!
 
I think all these thing were true at one time. Time has moved on and a class D or G amp could sound better than anything built to a class A design, well that is affordable. Capacitors and Transforms are expensive and have their faults too.

A truly good amp should have no finger print , it should not sound warm or musical or any other characteristic i.e. seen and not heard!
 
In the famous words of Peter Walker of Quad, an amp should act like a wire with gain.
If only those pesky speakers were perfect. :)
 
And to offer what I think I know about an amp's damping factor. It's something that I've generally found has been explained badly, and too technically, but here's my take on it...

When an amp sends current through a speaker system (which is a network of drivers and crossover components), there will be reflections echoed back in the direction of the amplifier. Coils produce back currents, etc. And there are various phase distortions that can be passed back.

That can all intefere with the signal the amp is trying to put out to the speakers, and the more an amp is able to resist such fed-back signals without damaging its output, the cleaner will be its overall output. Damping factor measures the ability of an amp to do that, and the bigger the number the better.
..Agree with the above but would add a few bits about mechanical inertia and reflected sound from baffles in the speaker driving the loudspeaker as a microphone. The inertia of the cone will typically drive the cone beyond its target position. A suitable DF kills that.
 
Thanks.
So feedback is undesirable. When an amp is designed, is it known at that time that it will have feedback, and that it is then a matter of how it will be dealt with, current or voltage feedback?
If Lyngdorf amps do not have feedback how come they can design it out when other manufacturers seemingly cannot?
As a once lecturer in this topic.. feedback is an absolute necessity in electronic design. Even the ancient Cathode Follower from Valve days used it. Adequate understanding of its limitations in the time domain was missing in mid 1970s and the demon of TID appeared.
 
But regarding capacitors. They work like battery’s. I’m no expert, that’s why I started this tread. But I have experienced when an amplifier is cold the sound sounds very cold/harsh then smooths out after about 30 mins. This is because the capacitors are turning them self on from off. They are cold and need to reach a specific temperature for the amplifier to sound right, hence like a battery.
No. The transistors will warm up in use and their gain can change,but that is not the way with capacitors
 

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