@kld10 wrote:
I always had over powered amps with lots of headroom. It’s always been beneficial I find. I am now at an extreme point where I already had a Mcintosh 300 watt per channel and I bought Avantgarde speakers at 107 db efficiency.
That means that I hardly use two watts. I am not bothered by the amp not working hard, but rather the question always goes through my mind that the preamp volume is always in the lower area. I keep hearing that a preamp works best between 75% and 100% (unity gain).So to your question, I would say, an over powered amp yes, but are we getting the best out of our preamps that are always in very low volume setting?
I do understand that there are many ways of attenuating signal but speaking in general here, I believe most preamps work best between 75% and unity gain
With very high sensitivity speakers like yours, depending to some degree on amp gain/input sensitivity, you’d likely always be in the lower end of the attenuation scale, be that with low or high wattage amps. The real impact of more amp power shows its face in the other end of the scale, certainly volume-wise and in regards to the cleanliness of sound, but indeed - as you imply - it also comes down to the chosen volume control implementation and whether it’s a linear or logarithmic variant (with the latter being the more appropriate choice here).
I very much adhere to the importance of headroom as well with prodigious amp power at hand in my own setup (>2kW per channel divided over 3 stereo power amps, fully actively), and that with an effective speaker segment sensitivity range sitting between 100 to 111dB’s. As to how that applies to the debate on "the importance of the first watt" I believe it has a tendency to be (over-)simplified into a matter of wattage capacity mainly and how low wattage amps shine here, but it doesn’t follow through in my own experience of comparing lower vs. higher powered amps in my specific setup context. As a matter of fact I use a class A/B ~600W/8 ohm power amp over the top horn section @111dB sensitivity, and compared to the previous 30W class A amp used here it’s no less refined or capable at lower SPL’s.
Other than the amp itself is the context of its use; does it look into a heavy or easy load, and how do those conditions affect the amp to perform nearer its peak? Active config. sans passive crossovers, that would otherwise meddle with the control over drivers, is an important factor here, and many would be surprised at how much active config. levels out the differences between amps, differences that would be more obvious via a passively configured speaker setup.
People sometimes get too hung up on wattage numbers and what a general, accepted stance could point to as being the best practice. Just use the amp(s) one feels has the better sonic merits overall, preferably with sufficient power to boot, but if that turns out to be a 28W class A Sugden that sounds great over a pair of low eff. Harbeth speakers, then so be it. Conversely using a several hundreds watts amp on very high eff. horns can be a sonic delight, at lower SPL's as well, although obviously this scenario has more in store for it wrt. headroom.