Recommended amplifier power

June 14, 2022
 by Paul McGowan

6 comments on “Recommended amplifier power”

  1. A significant factor is the reactive load of the speaker and the ability of an amplifier which is rated into an easy resistive load. Some amps can’t always deliver full power into reactive loads. I recall a well known 80 watt tube amp that was only good for one watt at 20 kHz. What makes great amps is the ability to drive reactive loads with little or no diminishing output and low distortion. And that costs money even on small amps.

  2. Last year I bought a pair of Klipsch Heresy IV speakers, and they sounded great at low to moderately loud levels, driven by an 80wpc Sony receiver, but once in a while I like to turn the volume a bit more and then they didn’t sound great, a bit grainy, and ? hollow. I wasn’t hearing any frank distortion though. The speakers are rated 100 wpc 400wpc peak with a sensitivity of 99 dB. I was going to buy a 2 channel 200wpc amplifier but ended up buying a 350 wpc into 8 ohms Parasound 2350 class D, and though I had to turn down the amplifier gain down significantly, the ability to turn up the volume of the preamp became effortless without graininess or lackluster sound. The Heresy’s now sing when I occasionally want to crank up the volume. On a sadder note, your Stellar Monoblock 700 amplifiers (which were out of my pocket book range) went on sale a month later! I am however very satisfied with the Parasound unit.

  3. Paul: Perhaps in this response you might add that the larger wpc amp will allow more satisfying sound at very low volume levels relative to the lower wpc amp. Much more detail at lower volumes . . .

  4. I never experienced a more “relaxed” sound from an amp with more potential output wattage. The only effect which could be found reproducibly was “stronger” bass. However for most of my loudspeakers I always preferred the sound from low wattage tube amps. And designers of active loudspeakers always smile and shake their heads seeing the huge power requirements of passive (non-horn) loudspeakers/crossovers.

  5. In the late 80’s I had a Yamaha A720 integrated amp powering my Klipsch Cornwall II’s. It was 105 watts per channel and it sounded pretty good. In 2008 I stepped up to my first real home theater amp, which was a Yamaha RXV3800, which was rated at 140 watts per channel (with two channels driven). It had some modes like “small club” or “amphitheater” etc. and they sounded pretty good but still not that much more impressive at higher listening levels than my A720. Fast forward to this year and I added a pair of SVS subs and stepped up to a PS Audio BHK Signature Preamp and a pair of PS Audio Stellar M1200 mono blocks. They are 600 watts each. The difference was unbelievable. I could hear nuances I’d never heard before. It was as though my whole music collection was new again. Then last month I added a pair of new Klipsch LaScala AL5’s and they added an entirely new dimension to the mid range. All that said, it was the (CLEAN) power of the M1200’s and the BHK Preamp that were the game changers because even at higher listening levels there is basically no distortion, and as Paul said in the video above, the amps are basically just cruising. I never fully grasped what all the buzz was about when people talked about “headroom”, but I absolutely get it now.

    1. It was a few years ago, when I read this article.
      But however, I don’t remember the name of the online magazine I read it in.
      But what it said, was this.
      A 25 watt amp, sounds as equally as good as a 250 watt amp.
      I’m not all that much for nontube amps, but I wanted to hear this for myself.
      And so, I went out and bought a 25 watt amp, and a 250 watt amp.
      And I tried them both out on the same pare of speakers.
      But what I quickly discovered, is that the 250 watt amp, out shined the 25 watt amplifier.
      The larger amp, had a hole lot more slam in the bass.
      And, it had more then enough currant to give me that bass too.
      But when I tried to make the smaller amp do the same thing as the larger amp, the smaller amp ran out of steam.
      Go figure this one!

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