Big amps

January 2, 2023
 by Paul McGowan

No matter what your speakers or your tastes in music are, a big amplifier—and I mean really big—will always set your system apart.

Take for example the BHK600 monoblocks. Now there is a BIG amplifier. Big enough that not that many people are able to have one.

But for the few that are able to enjoy the best in class, there’s simply nothing that compares.

And that’s an elusive statement because how does one make such a comparison?

For me, it’s an easy no brainer. (I get to play with all the toys. :))

Why big and powerful amps always elevate system performance remains a bit of a mystery to me. Sure, they are clearly more linear because of the extra headroom, and like a more powerful automobile engine, they are less taxed and therefore more at ease. But that’s probably not all there is to it. I think perhaps all that goes into a big amp: more power supply, heavier gauge wires to handle the extra current (solid buss bars for power in the case of the BHK600s), more output devices, etc. play more of a role than we as designers might imagine.

Perhaps at the proverbial end of the day, one could safely suggest big amps do not lend themselves to compromise.

Big amps are uncompromisingly better.

I hope someday you get a chance to experience one.

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47 comments on “Big amps”

  1. An active loudspeaker with state-of-the-art technology (Devialet Phantom 1) features some 1.5 kW resulting in 108 dB SPL and goes from 14 Hz to 27 kHz @ 6dB. I really wonder which audiophile aspects are hidden in conventional boxed high-end speaker designs which cannot be found in those low budget full-range loudspeakers with integrated DSP, near perfect step response and absolutely flat SPL versus frequency curve?

  2. “…there’s simply nothing that compares”

    Constellation – ‘Hercules II’
    Boulder – ‘3060’
    Ayre – ‘MX-R Twenty’
    Gryphon Audio – ‘Apex’
    Jeff Rowland – ‘Model 925’
    Halcro – ‘Eclipse’
    Naim – ‘Statement NAP S1’
    Pass Labs – ‘X260.8’
    Luxman – ‘M10X’
    Dan D’Agostino – ‘Relentless’
    …I could go on & on, but I’m currently (100 amps peak to peak) very happy with my 500wrms/ch/8ohm/10Hz-20kHz(+0.0 -0.1 dB)/<0.01%THD,
    dual mono ‘M6si500’ beastie.

    1. Martin i am in complete agreement. I am also not sure what too big for some to own is intended to convey, even though I tend to agree with Paul that having reserve power is always positive

      1. Willem,
        Most amplifier THD curves on a graph look like a saw-tooth,
        with the lowest THD point at about 85% of full power.
        So my ‘M6si500’ is going to be at its cleanest at around 425wrms
        …with some ‘chunky’ EDM that’s enough to fry my tweeters
        & blow my mid/bass drivers clear across the room 😀

  3. I don’t see it a mystery that big amps sound better. It’s as you say, Paul, because of all the bigger and better stuff that is designed into the bigger amps to make them sound better. Even so, if you put bigger and smaller amps behind a curtain, I think most people would be hard pressed to say which one they are hearing.

    Once I alternated playing real pipes and digital pipes from my organ console and asked a couple of listeners on the other side of the room to tell me if what they were hearing were real pipes or digital pipes. They were incorrect 50% of the time, which means they were guessing and could not tell the difference. A rank of real or fake organ pipes in front of the organ loudspeakers helps with the illusion.

    1. On a visit to the US Naval Academy two summers ago I was awestruck by just the sight of the organ in their large chapel…or was it a cathedral? If you ever get the chance…. 😎

    2. If you put a for example a Creek 100 watt amplifier a smaller PS Audio amplifier like Sprout or one of the others and a BHK600 mono pair behind a curtain and play them all at the same volume you will probably detect some character differences between all of them. You might even prefer the less expensive one, maybe not. But there won’t be some huge difference played at the same volume levels. Now if you push the lesser expensive less powerful amps to their limits they will show their shortcomings. Keep in mind there are amplifiers that cost more that the BHK600’s and are not designed to put out huge amounts of power. Do those sound better? You never really know until you live with the amplifier an extended period of time using high quality speakers. Some speakers will show bigger differences between amplifiers than others.

  4. Damn, yet again another Size Matters discussion. I guess I can throw away my “It’s not the size of the ship, but the motion of the ocean” t-shirt.

    1. JLawry,
      No don’t throw out said T-shirt sir.
      According to a few of my ex-girlfriends, the sentiment is absolutely correct.
      However, they did hastily add that a much bigger ship that moves
      extremely well in said ocean *is* the pinnacle of performance 🙂

      1. Well just great, because my room, which I have determined IS the most important part of my system, is also small. Well, at least I can likely get a bigger room someday. As for my “ship,” uh…….

  5. Before I went to active speakers I used to take over the words of a Danish friend „life‘s too short for small amps“, while big amps at the same time meant full class A, ss or hybrid.

    For the usual less efficient speakers and high demands regarding bass performance, I still see this admittedly snobbish statement valid. Would PSA have made the FR series semi active, no BHK600 would have been needed.

    And then there are also other, more efficient speaker concepts which (when bass demands are no absolute priority) benefit from tube amp virtues, no big ss or hybrid amp can deliver.

    But again, given the usual, medium to low efficient passive speakers, life’s too short for small amps 😉

  6. What I come away with from today’s post is the possibility (probability) that sound quality is more dependent on the material and design rather than some absolute number. Buss bars instead of wires…. Components used… bigger transformers… special purpose caps… N channel components… fuses… and so on. ‘Head room’ is just one small and possibly insignificant part.

    What ever happened to the less is more way of thinking?
    Is it the American bigger, badder, better, mentality that prevails?
    Are the power differences really just bragging rights? Or are they load and synergy dependent?

    If it’s components, buss bars and the like that make the biggest difference, then that’s easily proven within any given model. Doing so may also add to the price, or it may add to the profit margin.

    I suspect that once a certain level is reached, the absolute power rating / build has as much to do with how something fits in a product lineup as it does anything else.

    1. Less is more in many cases Mike. I’m still working on helping a friend with a system consisting of a Willseton 300B amp and the sixth generation of the the Zu Audio Dirty Weekend with all of the additional options. The first thing I would do is to swap out (not Roll) all of the tubes that come with the unit and replace them with much higher quality tubes especially a set of the brand new Western Electric 300B’s matched pair. I’ll figure out what sources my friend wants at a later date.

      There’s room for every type of amplification at this point in time and probably for the future as well.

      1. no disagreement from me Stimpy2.

        I also don’t think that a power rating alone tells much of a story.

        Must be fun perusing the audio market, even if it’s for someone else.

        Enjoy and a belated Happy New Year 😀

  7. I beg to differ. I think it depends on the music. Bigger is not always better. For example, I’d rather listen to a master cellist on a high quality single-ended triode amplifier. Mahler may sound more like the Berlin Philharmonic visiting Carnegie Hall on a mega-watt solid state amplifier but for intimate music with high emotional content I prefer simple amplifier designs (usually with tubes in the circuit somewhere).

  8. I’ve had a recent series of three amplifiers. All were Class D, and all had milliohm output impedance; the rest of my system was basically unchanged. The first was a 200/400W into 8/4 ohms. Then I went to a 300/600 and noticed that the transients were crisper. Now I’m running the M1200 monoblocks (600/1200), and the difference is profoundly better. Better transients and much more fine detail.

    Why? My theory: in the mechanical world, power = force x velocity. The speakers are an electromechanical system, and maybe more power allows the speaker to better follow the signal. Force driving the velocity of the drivers. I am still puzzled about how the amp can see what’s going on at the speaker.

    I can say that the improvement with power has been steady and dramatic. I don’t ever want to go back.

    1. Hello Charlie,

      There may be criteria you left out.
      The 1200’s use a tube input stage – did your other amp do that?

      I personally get stuck on the fact speakers are primarily current driven devices. My thought process goes to the idea that an amplifier has to be able to maintain a somewhat stable voltage while the current rapidly changes. No sag at all in that voltage as the current changes.

      1. Mike,

        No, my other amps were all solid state. BUT, I could hear a clear difference going up in power with them, so I know it’s not the tube stage in the M1200 that’s responsible.

  9. Happy New Year, Paul!

    “Big amps are uncompromisingly better.”

    This simply is not true as a maxim of general applicability. This issue is totally speaker dependent and preference dependent.

    Many audiophiles believe that the simpler the circuit and the smaller the output stage, the purer and the more natural and convincing the sound. Many audiophiles hear that massed output tube amps are not as delicate and nuanced and realistic as SET tube amps.

    Even Nelson Pass, manufacturer of giant transistor amplifiers, makes his “First Watt” series of small, simple circuit amplifiers.

    I think loudspeaker requirements and personal preferences drive amplifier selection.

    1. Nelson Pass had a third company called PASS DIY where he used some new circuit ideas and experimented with them by making kits. If they sounded the way he imagined, he used these preliminary designs by re-creating them under the First Watt name. They were much improved versions of the kit. I built one of these amplifiers and a Korg preamp for my older son. Total cost including chassis and and cases was less than $650. It’s hard to imagine that the SQ that came out of this combination was incredibly musical… I was floored by how wonderful they sounded. This man is one smart cookie.

    1. I just saw an interview with Nelson. He spoke about his favorite First Watt Amp, the J2. He usually made 100 pieces of each amplifier but continued to build more of most of these amps custom upon request. Many years later, he’ll still build a J2 on request as well.

  10. I also believe in the low parts count Pass philosophy. My SIT3 is a great sounding amp, very close to a triode type output because of the Vfet outputs. Alas no more new Vfets available in the world.

    1. Did Nelson really run out of these
      V-FETs? I know that he bought more than tens of thousands of these active components because he knew he would use them in all future designs. He has more than one warehouse filled with loose active components.

        1. If that’s the case, I stand corrected but I know that he is hoarding an incredible number of FET’s. You can look back in the Audiophilliac YouTube archived videos to find several half hour plus interviews with Nelson when he spoke about his purchasing power when companies that he wanted to continue to do business with closed.

  11. It’s system/room dependent & program dependent. Crest factor of the recording (s)! Etc.

    So, yes often times big Amps can keep up with the current(power) demands of Demanding speakers. Dynamics of live music with minimal compression. And listening to ukulele or dulcimer is not gonna strain many well made amps.
    And like many of the denizens here I’ve done my share of A/B single blind comparisons. I wouldn’t bet the farm.
    Two weeks ago I listened to a big ambitious amp speaker combination. Vandersteen 7’s driven by their bespoke boat anchor Amps. Wow!

    And has already been mentioned active speakers or semi active speakers level the field. Ymmv.

  12. I like active speakers with DSP built in.

    I believe the bass especially is better having the amps built into the speaker. I think somewhere between 400-1000 watts.

    Then use the amps of your choice for midrange and treble.

    My speakers sound Dijon’s this way.

  13. Power has been the obsession of the USA hifi scene science the 1970s (so says my HiFi book).

    The classic British Naim amplifier has peak transient power about 5 times average power, so the 500DR is a 140w amplifier with 700w transient power. Equally important, it has a separate high quality DC power supply.

    The best amplifier I ever heard was the Trilogy 995R, a valve hybrid 40w Class A (55w peak) 200w Class AB. It was in Class A mode with Wilson and it was astonishing.

    Add to FR’s list the Naim Statement, 785w/8ohms average power, 9,000w/1w transient power. Makes BHK600 seem a bit underpowered.

  14. As has been commented above “size matters”! All kinds of size matters. The size of the room, the size of the speakers, the type of speakers, the type of music and probably a few things that I have missed.

    I have a large room and large dynamic speakers each having three 10″ woofers, and a large powerful solid state stereo power amp that uses an NFET fully balanced design. I took guidance in sizing the amp from the speaker firm ATC. They build both passive and active speakers. When they build active speakers the use a dedicated amp for each speaker. The tweeter gets a 50W amp, the mid range gets a 100W amp and the woofer gets a 200W. Using this guidance I got an amp that has 750W per channel. All I can say is it sounds great.

  15. I don’t have the size room or mega-speakers that can take advantage of that little extra control and ease of big watt amplifiers. My dual-mono 200 watt amp gives me the top to bottom balance, dynamic contrast, liquid midrange, naturalness and spatial presentation that I look for in an amp for the music I play in my room.

    If I were to replace my amp with a 600 watt amp, I doubt that I would hear the difference providing it gave me all the characteristics of my 200 watt amp.

  16. Nearly all big amps I’ve heard in real life rigs did nothing for me – all they do is make it more obvious that that the playback chain I’m listening to has issues; if your car has poor suspension then going faster because you have a bigger engine just makes the driving even more dangerous.

    Interestingly, the first good setup I had over 3 decades ago used a battleship power amp – it happened to be a good one, so I got the results. And I’ve been going smaller ever since, 🙂 . It’s the engineering of the unit that counts, and the integrity of the overall chain – I’ve designed my own chip amp setups, and used consumer integrateds with the same; get the package working correctly, and it will easily be superior, in the listening areas that matter, to some beast that gets some numbers looking impressive …

    The one advantage of bigger amps *is* that the more substantial parts of the power supply are just loafing along most of the time – so, in a range from some manufacturer, get the biggest you can afford, if all else is equal.

  17. I have a 27 cu. ft. vented subwoofer tuned to 15 Hz that will rattle the windows and shake the house to its foundations with just 50 watts of power, which is only one-third of the maximum rated output of the 175-watt amplifier I employ. So, you can have a monster subwoofer enclosure or a monster amp to drive it. Having both at the same time is overkill.

  18. I agree. Certainly plenty of reserve current at ANY time and frequency is key, but it’s so many other things too… Reproducing very complex waveforms, damping factor, sound stage width and depth, matching amp to speakers, low noise, coloration, timbre, the stages of amplification prior to the amp, power supplies, great caps in the amp’s signal path, tube VS SS, good heatsinks in SS, magical transformers, circuit feedback, crossovers, speaker design (ported, horns, electrostatic), cabinet volume, efficiency of speakers, the room, imaging of speakers, clean power ‘in’, spikes or isolation from the floor, speaker placement, composition of the floor, sound treatment, micro-phonics… I don’t know class D at all. I don’t have many answers, but my ears & brain are the best ‘measurement’ tools I’ve found, (although they change over a lifetime). ‘Effortless’ and ‘musical’ sorta sum up the results I listen for. Leonardo Da Vinci said ‘Details make perfection, and perfection is not a detail.’ 🙂 To me, great system design truly approaches giving us that magical ability that we all have to say, with certainty, ‘That’s live music’ from the far reaches of the parking lot! Hat’s off to all of the people who can make that happen! Thank YOU!

  19. Idiotic audiophile magic & fairies beliefs:

    The feeling for many hardcore audiophiles for years was that big amplifiers were intrinsically inferior.

    Big, powerful amplifiers were mere brutes; brute force devices, incapable of subtlety, delicacy, resolution, or true high end sound. Big amps were only applicable to public address aplications, such as some stoner, heavy metal display, for which the only relevant criteria were SPL.

    Big amplifiers were big, and so they were unwieldy and heavy; possessed high inertia, and thus were slow and crude. Only small, light amplifiers were truly able to reach for audiophile realm criteria.

    I knew a guy who truly believed all of that crap.

    To a great extent, those superstitious notions were fueled by the editorial stance of Harry Pearson’s Absolute Sound, which routinely penalized large amplifiers merely for daring to exist, while praising weakly powered products, such as those produced by Electrocompaniet, among others.

    The other source for those beliefs were an ignorance of basic principles of electonics and physics, along with a distrust and often a rejection of both.

  20. Wow, rarely so much disagreement to a Paul’s post. I guess this one would have needed a bit more depth to clarify the why‘s and what for‘s regarding big (good) amps, as there are good reasons for them under several preconditions.

  21. I was revealing one of beliefs from an extensive web of magical thinking to which many audiophiles subscribe. Didn’t ja git it?

    Here’s another example audiophile superstition.

    An audiophile had new electrical service installed for his house, including a new circuit breaker box. Brand new cabling supplying his home with electicity from the transformer supplying his block.

    He then announced that he was waiting for the electical service and its cabling to “break in and the sound to warm up”.

    Someone needs to start selling bridges to these people.

  22. So here is my feeling of rationality.

    I think the dual monoblocks BHK 600 with a P20 feeding the FR 30’s I think there is no better quality than that. Only different.

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