Do low power amps sound better than more powerful ones?

[Vinyl-ant]

My take is thus. Power supply. Its always about the power supply.
Watts are a largely irrelevant number in a normal domestic space unless you have some very inefficient speakers, or speakers that have odd impedance characteristics.
clean watts with a good power supply backing them up should be plenty for your house.
I have had everything from less than a watt 6em7 spud amps to 400w sand amps and the watts are not the crux of the good or bad sound.
It is always about power supply and system matching.
To say that you need x amount of watts or don't need more than x amount of watts is far too simplistic.
One of my fave amps i have had was an 8 watt rotel ra211 from the early 70s. It just sounded lovely. Another is my f5, 25 watts and ultra clean. Another is a crown pa amp i had that was 400w, it was the defenition of an iron fist in a velvet glove. But i would not use it with my big fanes because it would have the windows out without touching the volume control.
There are a million ways to skin a million cats.
There is no spoon

[Geoff.R.G]

My take is thus. Power supply. Its always about the power supply.
Watts are a largely irrelevant number in a normal domestic space unless you have some very inefficient speakers, or speakers that have odd impedance characteristics.
clean watts with a good power supply backing them up should be plenty for your house.
I have had everything from less than a watt 6em7 spud amps to 400w sand amps and the watts are not the crux of the good or bad sound.
It is always about power supply and system matching.
To say that you need x amount of watts or don't need more than x amount of watts is far too simplistic.
One of my fave amps i have had was an 8 watt Rotel ra211 from the early 70s. It just sounded lovely. Another is my f5, 25 watts and ultra clean. Another is a crown pa amp i had that was 400w, it was the definition of an iron fist in a velvet glove. But i would not use it with my big Fanes because it would have the windows out without touching the volume control.
There are a million ways to skin a million cats.
There is no spoon

I agree with that.

The problem, as you know, is that amplifier power is quoted in Watts RMS. The Watt is a unit of power but in an AC system W=V I Cos Φ where 𝛟 is the phase angle between voltage and current. Even if you do so at a fixed frequency into a load with a fixed reactance you don't actually measure the power output from an amplifier into a real world load because in the real world 𝛟 isn't constant. I seem to recall that amplifier reviews derive power output by using a resistor bank as a load, which in no way represents any known speaker. Hence the NVA practice of quoting power transformer rating is more useful. Given that speakers are current operated devices a rating in Amps might be more accurate, but not necessarily more useful.

The other issue is that, realistically, music in a domestic environment doesn't actually require much power; 1 watt into a suitably efficient speaker can be unacceptably loud. If you don't have efficient speakers you might need somewhat more power before the level becomes unacceptable but, as I said above, an amplifier rated at 150 W is perfectly adequate for a large space. Certainly my 140 WPC amp is over the top for my lounge, even my 50 WPC Quad 306 is more than enough. However it is worth noting that, as ant says, the power supply is key, the amplifier is constrained by the current available from the power supply.

Now to get to the point, what matters is the ability to deliver current, amplifier rated power might appear to give an idea of that but it doesn't. The reason being that different manufacturers and testers use different methods to derive the available power. That means that the results aren't equivalent across the board. A Quad Watt may not be the same as an NVA Watt (if NVA rated amplifiers in Watts that is). The data can often be found in the manuals that come with an amplifier but, if you don't know how to read it, it still doesn't help. Hence manufacturers have tended to produce amplifiers with high rated outputs leading the unwary to believe that more watts is better, which might be reasonable if the power rating reflected the ability to deliver current.

A conservatively rated transistor, run well below its power capacity is more likely to deliver clean power than one that runs hot. You find such arrangements in relatively lower powered amplifiers, partly because it is cheaper to use an over specified transistor bought in bulk than a lower specified device bought in low numbers. What ever works for you is the right answer, just don't assume that a high power amplifier is going to be right without trying a smaller one first.

[CN211276]

Too many people place far too much emphasis on watts, something I was a bit guilty of myself. I think it has a lot to do with marketing . I recall the advice I received from Richard when I was undecided between the A80s and the A70s. He enlightened me about the importance of power supplies and as a result I bought the former. Since I have discovered, through my ears, how important good power supplies are to digital and since last year have had Sboosters powering all three digital source components in the main system.

[Geoff.R.G]

Too many people place far too much emphasis on watts, something I was a bit guilty of myself. I think it has a lot to do with marketing . I recall the advice I received from Richard when I was undecided between the A80s and the A70s. He enlightened me about the importance of power supplies and as a result I bought the former. Since I have discovered, through my ears, how important good power supplies are to digital and since last year have had Sboosters powering all three digital source components in the main system.

I have never understood why Richard was so vilified by the Hi-Fi mainstream. Much of what he said, and did, appears to be common sense. You will never get more current out of an amplifier than the power supply is capable of delivering. Likewise adding components won’t make the signal path any cleaner, how can it when we already know that heating induces random noise, add a resistor and it will get warm random noise is inevitable.

Unconditional stability isn’t really necessary provided the designer specifies the load circuit requirements. Which Richard did. I am currently listening to Radio 3 at a level which can’t be heard outside the room but it is adequate. Later on I will be doing sound for a wedding at a level which will be considerably louder. The main amps will not be massively different in rated power what does that tell you?

[CycleCoach]

Some amplifier circuits sound better than other designs.

Some power supplies are better implemented than others.

And some amplifier circuits (and yes, I do have one particular beauty in mind) benefit from improving the power supply by beefing up, doubling (or even tripling) transformers so that input and output stages can be the best that they can be.

Thing is, if you only listen at low levels, or you're a devotee of simple acoustic music, or solo vocalists, it's quite possible you won't notice a great difference.

As in all things, your own ears are the sole arbiters of quality.

Use them wisely.