Thanks Steven but I hate to tell you, whatever amplifier you own is already flawed in that respect. The maximum perfectly linear response of devices averages between 10% and 20% of the total available headroom. This renders the remaining 80% of the amp has less than linear.
So, let’s define terms. By pure linear I mean the area of amplification that is an exact copy of input vs. output without any feedback (local or global). You can see somewhat I am referring to in a simple transistor linearity chart like this one:
This is not a great example, sorry, but I didn’t have a lot of time to search for you. Basically, transistors and tubes are not all that linear - which is why we do things like add local and global feedback in an effort to linearize them. This is one of the reasons why low feedback (or) zero feedback amps are typically made with high voltage so you get the maximum linearity region.
My point about amps is the same. If you assume an amplifier’s sweet spot is 20% of its total output then you can see how a very power amplifier (of proper design) can be more linear and thus better sounding that a smaller amplifier that is stretching its linear regions.
my current speakers Elac F5 140 watts into 6 ohms sensitivity 86 db
my current amplifier is Marantz MM 7055 210 watts into 6 ohms 20% of that is 42 watts
my speakers 140 watts but my amp sweet spot or at it’s best only 42 watts that would kill my speakers over time
My apologies, I intended to refer to distortion usually shown as 1khz continuous power. Class D tend to be very linear, valves not. See for example on Stereophile the Devialet D-premier and the Macintosh 275.
Coming from an island that favours low powered amps, years ago I recall distortion and noise if you pushed them hard, which you don’t get on well done Class D, D hybrid or current dumping amplifiers, or at least the ones I’ve used. You can push them no worries.
Amplifier sweet spot is 10-20% 210 watts amp best is at 42 watts so I need a bigger amp get bigger sweet even with 900 watt amplifier 20% of that is only 180 watt (headroom)?
I think that the instantaneous power requirements during transients (0.1 second or less) could easily be 10x or more of the overall steady state. That may be where the headroom from more available power comes into play. I think the requirement goes 1 watt then 3db more is 10watts then 3db more is 100 watts, correct?
If you are not happy with the sound quality, THAT would be a good reason to upgrade either the speakers or the amp or add a subwoofer (sorry @elk) . If you are happy with the sound quality you’re getting, then there really is no reason to change anything.
Doubling the amplifier power increases the acoustic power by 3dB . For example: Increasing an amplifier from 25 watts to 50 watts ( double the power ) increases the acoustic power by 3dB . Increasing an amplifier from 25 watts to 100 watts (4 times the power ) increases the acoustic power by 6dB. +10dB is x10. +20 is x100. +40 is x10,000
Thanks. I thought it was 10x for 3db. I guess the thought was having some extra money (watts) in the bank is a good thing to get thru transients cleanly.
Paul, if we’d theoretically connect the same amp to a speaker with passive crossover, with active crossover and a fully active speaker (if this isn’t the same as the second example just with an amp built for the speaker)…would there be another relevance of the amp linearity except that the amp would operate in a lower range for the active variants, as it doesn’t have to go through a passive network?
Do you have a guess to which degree an amp or n an active design operates in a lower range if it doesn’t loose power in a passive network? Does it need 80, 50, 30% of the power?
Technical details aside, honestly, EASIEST and probably BEST way to figure out what speaker works best with your amp, is to TEST THEM!
I have a plan to take my Amp to a dealer next week and compare the same source on the amp with various speakers (3 pairs for now) to see which works best.
Generally I’ve found that GOOD Class A/B are much more forgiving and work across more speakers easier, while Class D provides more power for less money and heat, yet don’t always sound great with demanding speakers (LS50 an example).
Basically PS Audio sells behemoths of amplifiers and power regenerators and thus Paul makes a point about the more power the better.
What is actually best for you depends on a whole lot of other things.
You can have great sound out of 8 W class A amplifiers with the right speakers in the right room, that sound as good as the 300, 600 or 1200 W beasts on different speakers in that same room.
Go out to dealers and listen to different sets with different philosophies that are basically based on room and speaker characteristics rather than just amplification power. You will be surprised what you really need based on what you can afford and what the dealers offer you you to listen to.
What is more important is reliability. That the units in a sound system keep on playing. The EUR 1800 PS Audio unit in my home office quit working after just 1.5 years. I learned to appreciate the EUR 1000 Yamaha AV receiver in the living room really fast after just a couple of days without music in the home office. And then all the hassle to get the unit repaired like digging out the paperwork, explaining what Is the matter, disconnecting, packing up, transportation, no music.
Based on other PS Audio users experience reported in this forum that was confirmed by my own, I decided to leave the PS Audio unit after repair at the dealer and get equipment from a larger but more mainstream manufacturer hoping to see those units to play good sound for longer than 1.5 years.
A series of videos about the constant improvement processes of quality control at PS Audio would be very interesting too.
While I generally think something like the thread title is valid at least from a measurement point of view, its relevance will have to do more with other qualities of the stronger amp related to the weaker. Usually you can’t inherit the same quality in a stronger amp as in a weaker for the same price.
Another well used argument from another sales point of AB amps is, that they play Class A up to a few watt and that one hardly needs noticeably more power to listen at usual levels. Both arguments don’t fit together too well. I admit I believe the first more than the second, but both don’t help the customer in the practical situation in any way as they both are usually not practiced.
High power class A/B amps have become Dinosaurs measured by price, size, weight and power consumption. While it may be true that they sound better, for many class D are compact, can be beautifully designed to fit into a normal living environment and are gentle to the energy bill and thus to the environment. The argument of poorer sound quality vanishes more and more considering the latest class D designs.
The young MP3 earbud generation, if they will ever become interested in static speaker systems, couldn’t care less about that little Sound Quality improvement of class A/B amplifiers weighted against the disadvantages.
So class A/B becomes even more rare and due to the low production numbers more expensive especially if you are told that their ideal operating range is at 10% to 20% of their rated power.
An issue with cheaper Class D amps is that if they don’t have a particularly good design they can be a bit bright, and quite a lot of smaller speakers (and larger ones) can be a bit bright. Bright amp + bright speakers = horrible, especially in a home office where I listen for hours. So options include getting smaller speakers with a ribbon tweeter, better speakers generally, and a Class A/B amp, which is an easier listen. There are popular models from the likes of Hegel, Cambridge Audio and Audiolab, Naim, no doubt many others including Yamaha, Denon etc. I get the bass from a small but good subwoofer (REL S series), so am in the unusual position of having a subwoofer in my small office, but no subwoofer in my main system in a much larger space.
If large Class A/B amplifiers are dinosaurs, where are valve amplifiers? I expect there will be a market for them so long as the generation of people who grew up before Class D are still alive, and there is no doubt they can sound fantastic. They are big and expensive, which is an issue for some people, but not for others.
Valves and Class A/B may distort significantly towards full power, whereas Class D generally do not, so the headroom issue disappears. Then valve amplifiers soft clip, etc. All very old arguments and views are probably entrenched for most people.
I do not disagree with what you have said there is a lot of money to be made even with dinosaurs.
Class A/B will be around as long as there will be components available like tube amps. If you refer to Hegel and the likes you can even buy decent size amps that have 80 to 150 W power output rating. Which is plenty for good sound quality, especially in a home office.
However, if you seek large power reserves, than high quality class A/B become exponentially more expensive, heavy and larger than good quality class D amplifiers.
