What is your experience with amp power?


So I wanted to know what my fellow audiophiles feel about power.

I realize that some speakers are current hounds and need a prodigious amount of power or watts (lets say Maggies). But my question is for speakers that do not. Speakers that are easy to drive, or maybe just higher in efficiency and can be driven by a modest tube amp or even an adequate receiver. 

What is you experience with high power, high current amps ? Do your speakers sound better with more power? At low volumes, in a small or medium sized room? Do you think the quality of the music is dependent on higher powered amps?

128x1282psyop

In general, more power, more better for most all speakers. So let’s say you have a choice for the same amp… like Pass 150, 250, and 350. Higher power sounds better at low volume and high volume.

 

However, choices are never that simple. Undoubtedly the choice will be among different amps and technologies.

For me, once I left solid state amps, I did not want to go back and I would settle for a lower power tube amp (of high quality) over a solid state.

Ultimately, you have to listen to the character of the amp… then I would go as high on the power as you can. Without going overboard. If my speakers were 105db efficient, I would not pair with 350 watt amps… instead I would go much higher in quality and go 100 wpc or something like that.

I do not like high efficiency speakers, because they usually have poor dynamic floor. It's a trade-off. Heavier speakers can get a lot better dynamic range from quiet listening to very LOUD.

Not all amps are created equal, and not all watts are created equal. I’ve gone the gamut from a 55wpc Technics SA500 receiver to a 70wpc Yamaha A500 integrated amp to as high as 255 wpc in a Hafler DH500, down to 150wpc in a NYAL Moscode 300 hybrid, to a Distech LS-2 (modded BKST-140) @ 100wpc, all the way down to about 12 watts per channel from KT66 tubes in triode. Every amp on that list sounded progressively better to me....playing louder did not. All my speakers have been average efficiency, and the amps I’ve liked the sound of best are my current 12wpc monoblocks.

I know it’s subjective, but I suspect that synergy and paying attention to the whole system chain is a more critical consideration than just amp power.

For 15 years I’ve been running Tannoys, between 91 - 96dB. I play loud. I like tubes. I don’t think I’ve gotten to the point yet where I have "too much" power. My most powerful amps, 250 Watts/ch and 300 Watts/ch tube monoblocks, have had distinct advantages in dynamics, bass, and "driver grip". Yes, even on the big 96dB / Watt Tannoys! I’ve gotten great sound with lower power amps, but there are clear advantages in the higher power levels that you won’t get until you get there. Headroom matters. My 300 Watt VAC Master monos in particular are just in another world of performance compared to all prior amps - the 200 Watts/ch 200iQ monos (really more like 140 Watts./ch into 8 ohms) aren’t even in the same zip code.

I think higher power also greatly lowers the risk of "problems", in my experience. With a vinyl source there can be a lot of feedback and LF energy to deal with, and you DON’T want to risk the amp clipping from that. It' always better to have the extra headroom. 

If you listen at "75 - 80dB peaks max" or whatever, then you can safely ignore my observations :)

If you want to play (loud), you have to pay. Big powerful expensive amps exist for a reason. They work in most applications and let you not worry about coming up short on power. And for some reason, unknown to me, big amps add power and weight even at low volumes, although I have no idea how that works. Better to have too much than too little. On the other hand my 25 watt Quicksilver Mini-Monos are my favorite amps? 

Power has nothing to do with sound quality.  If that were true, then anyone could make a high powered amplifier.  Comments about power and headroom are completely false.  Power has really nothing to do with headroom.  And higher power sounds better at low volume and high volume is another false statement.

@knotscott - is going in the right direction.  I have Vandersteen model Seven speakers 83db driven by 28wpc stereo amp that sounds better than the 220wpc amp and even the 100wpc amps we have.  In theory, no one I know would even think to use a 28wpc amp on the Sevens.  But so far it has outperformed the other amps by a significant margin.

Happy Listening   

 

@bigkidz 

have Vandersteen model Seven speakers 83db driven by 28wpc stereo amp that sounds better than the 220wpc amp and even the 100wpc amps we have

Actually I don’t find this particularly surprising. If this is a tube amplifier I suspect excellent transformers and power supply are largely responsible. I expect that most responses will be in favor of more power is preferable.

Charles

I will add another vote for quality over quantity. I was caught up in the whole more is better for over 5 years. I had amps up to 300 watts from the likes of Bryston and McIntosh. When I finally tried a lower powered tube amp I felt I had been had. I really think the sound of the amp is far more important that the watts. I think for most people and speakers that 30-40 watts is all that’s needed. 

Right now I'm listening to Eva Cassidy I Can Only Be Me through 86dB Harbeth's and 2 RELs at a little over 1/4 volume with a 35wpc Raven Audio tube amp.  

82 dB SPL peaks 10ft from the mains, sounds awesome. My room is 60ft w x 25ft d open plan.

Big amp power is not a necessity with the right speakers but is surely nice to have if you got it.

Depends mainly on how far you are from speakers and how loud you want to go. Some speakers will benefit from higher damping factor in particular , others less so.

Having said that, more power in a line of amps will never hurt. Much like a bigger engine in a car. Making music can be a lot of work, especially with the lowest frequencies. If you skimp on those you can get away with a lot less power. Power needed for flat response increases exponentially as frequency gets lower. You may never miss having that truly extended low end response if you don’t but you are missing out on something if not.

I used to sell many popular lines of amplifiers to a lot of people. Nobody who ever compared ever preferred the sound of a lower power amp in the line to a higher one. But when comparing different designs from different vendors, that’s more apples and oranges and harder to predict what will be preferred.

This talk about the need for power and how bass is better really hasn’t been my experience. It’s why I ended up with high power amps for so long. I’ve had two tube amps in my system since ditching the high power and both amps make far better bass than any of my giant ss amps did. The high power ss did make tighter bass.  My issue is it wasn’t accurate or full to me.  I feel like sometimes we want our bass not to reverberate, yet I think that’s what bass is. Anyways I really feel it’s personal preference like everything in this hobby. I would encourage everyone to try both low watt tube amps and high power ss and see which they prefer. Far as a need lots of power for speakers that are 85db sensitive or higher I just don’t but it. People act like 30 watts is nothing then they suggest 100 watts. It’s literally less than 5db difference in max volume. Unless your truly maxing out your amp it just doesn’t make since to me. 

It also depends what are you looking for, and how your hearing is.

For most of us going for higher power is a no-brainer, as most of us have no hearing above 14kHz or so.

However, in case your hearing is still intact, and you are (un)fortunate to hear out to 20kHz, then there's a hard stop. I did this test yesterday - two amps going into a 89dB/Wm true 8R load full range speaker, no crossover, extremely revealing in the high frequencies up to 23kHz. So, easy and direct load and no interference from crossover. I used two amps to drive the speakers.

Amp 1 - 0.6WPC Darling amplifier (SET vacuum tube).

Amp 2 - CJ Premier SA350 Legendary 350WPC solid state power monster. (Which is one of the least fatiguing high power amps you can find.)

To my huge surprise I could not listen to the CJ any louder than I did with the flea-power tube amp! Why? Because yes, it could play MUCH louder, YET the level where it played WITHOUT NOTICEABLE FATIGUE was actually below the level the 0.6W Darling played.

If your hearing is compromised in the HF region, you can push your powerhorse quite a bit more before you notice ANY signs of fatigue. You might be able to use all of it....

Good luck! ;

 

 

 

 

 

Power is good and watts are watts, no such thing as better watts. But speakers are not resistors; they are reactive and good amp design(often great power supplies which don't show up in specs but do in sound) does matter when feeding real life loads. How an amp responds to reactance matters. Some amps ring a little bit into bad loads and take time to recover. Some amps can't produce power into bad loads only resistors. I recall a revered 80 watt tube amp that only put out 2 watts at 20 kHz into real loads. And the story can go on and on. The best is to have a quality amp that works into reactance AND lots of power. You'd be amazed how much power may be needed for split seconds(30 or more dB) to make clean dynamic transients even though the average power being used is only watts.

Most tube amps soft clip. Most SS amps hard clip. Many newer Class D amps also soft clip. Soft clipping gives the illusion of going louder overall (like “loudness wars”)  but the dynamic peaks are suppressed.

Clipping is public enemy #1 of good sound. Soft clipping is sonically more acceptable to most than hard clipping. More power when needed is the antidote to clipping. Them’s just the facts…..

The "quality of the music" depends on the "quality" of the amp.AND the power. Sometimes mutually exclusive.

It seems the closest thing to a perfect world of amp employment is

via Bi-Amping. That said I use an Integrated. 

Been thinking about amp power for a while now.

Diy builder of amps, so I spend time thinking about this.

The issue of bigger power amps is more about the power supply than the number of gain devices at the output stage I think.

Unless you are driving inefficient speakers to ear shattering volume in a huge space, I wonder how high on the watt side you actually go. I wonder how much of the dynamics are managed by power supply as opposed to number of gain devices.

Built a 30W class a amp with a 500va transformer, and 192k uF in storage.

That amp drives my 83db efficient speakers with much better control and dynamics than my 100w Adcom. Apples and oranges, I know, but it speaks to what power in an amp is important. All of it matters, but if given a choice, I would choose lower power, bigger power supply, than give versa. The 30w amp never feels like it’s straining.

Im also thinking, you want to get into the power band of an amp a bit for the speaker’s sensitivity and how loud you listen. Don’t want to over drive the amp, but you want to get into the linear part of the amps power band.

Curious what others have experienced.

 

I ran for at least 15 years on a 20wpc Philips receiver (when Phil was making some fine gear) and it was plenty for my purposes and rocked the house when needed.

From my experience I generally agree with others that at sound levels of 85 dB or less one need not have an amplifier that puts out hundreds of watts per channel. Yes, how loud you listen, distance from the speakers, ceiling height, speaker sensitivity, all have an effect. But some speakers present particular challenges for amplifiers.This becomes more of an issue with larger inefficient speakers, but also with any speakers that have wide swings in their impedance curve at different frequencies. Some speakers stay close to 8 ohms or 4 ohms most of the time, while others can drop as low as 2 or 3 ohms, and a few drop even lower than that at certain frequencies. Those low impedance drops require more power from an amplifier, particularly if the drops occur in the lower frequencies reproduced by the larger bass drivers. You need to know the impedance curve of your speakers and determine if it is relatively flat, an easy load, or if it drops to a very low impedance along the frequency curve, a difficult load.

I had a personal experience with a pair of speakers I own, which are large 4 ohm, floor standing speakers with 10" woofers, but drop to a bit below 3 ohms at some frequencies. I brought home a very fine 120 w/ch @ 8 ohms Luxman integrated amp to audition at home. At modest listening levels the amp sounded fantastic. When I turned up the volume to a "live" level while listening to a symphonic piece, the amp very audibly started clipping. I immediately shut off the music to avoid damaging my speakers. Sometimes you end up learning things accidentally - the dealer explained the issue when I returned the Luxman unit. Not every amp can handle a load below 4 ohms well. Too bad because at modest listening levels it really was outstanding. But my old dual mono amp rated at 250 w/ch at 8 and 500 w/ch at 4 ohms never breaks a sweat driving my speakers, even at volumes in the 95 dB range. I can’t say the greater power rating makes my amp sound better at lower volumes, but that may be a trait of my speakers, which sound better at higher volumes. Then again at higher volumes there is more discernible bass, something true for all speakers, which is why old gear had "loudness" buttons or switches to boost those frequencies at low listening levels.

Happy listening.

Some speakers benefit from current and damping.   Not all watts are created equal.    Most good SS amps deliver a lot of current and have corresponding high damping. Not a fan of lesser built high power SS amps that deliver lots of watts but not much current.  

Some speakers benefit from current and damping.   Not all watts are created equal.    Most good SS amps deliver a lot of current and have corresponding high damping. Not a fan of lesser built high power SS amps that deliver lots of watts but not much current with most speakers. 

In general smaller speakers with extended bass, which tend to be the most popular and the least efficient, require high power high current SS amps to sing. Larger and more efficient speakers may be easier to drive but often lack of extended bass is the reason. So you have to know what you are dealing with in regards to speakers and how well they might perform in a particular room and make sure the amp is up to the task. That’s basically it in a nutshell. Bigger rooms are harder to conquer. Small ones not so much. It’s largely a matter of scale. Just avoid clipping or over driving a lesser speaker. The devil is always in the details.

More power doesn't now, nor will it ever, equal better sound. If that were the case, a 2A3 Sun amp would sound terrible since it puts out a whopping 3.5 wpc. This should be common sense but based on most of the tripe posted here, common sense in the audiophool world isn't very common.

Some build a system around a speaker, some around an amp. Pretty loaded question with many possibly answers... I might venture to say though that the beauty of an amp be not judged by it's power!

I'll share my experience. Along with a pair of Legacy Audio Focus speakers which are low to mid 90's efficient, I was using a Plinius SA-103 power amp that delivered 125 watts into 8 ohms and 220 watts into 4 ohms. I always felt that it lacked a bit of power and indeed there were times when listening at high volume levels during a sudden transient, it would go into protection mode. I decided to sell it and replaced it with a Plinuis SB-301MKII which offers 310 watts into 8 ohms and 470 watts into 4 ohms. The improvement was amazing. I had a much deeper dynamic range now and everything sounded more balanced across the frequency spectrum. I have never driven this amp into clipping or protection mode and I'm afraid to think what it would take.

In contrast in my second system, I am driving Legacy Audio Signature III's with a small Plinius (yes, I like Plinius and Legacy together) 9100 integrated rated at 120 watts into 8 ohms and it drives them with authority. I recently picked up a small EL34 tube amp that puts out a whopping 8 watts for another project. I hooked it up to the Signature III's and was amazed at how good it sounded......with the right music! And there is the rub! When playing a cut from say, Passenger with an acoustic guitar and vocals it has plenty of power and can play loud. In contrast switching over to a London Grammar track with lots of deep bass, you can hear the tubes go into clipping easily. As a matter of fact, it can barely play some of their tracks.

So my conclusion is, the more power the better except in some circumstances where you may be listening to acoustic music or light jazz then you can get away with less power. The key to each of the aforementioned amps is current and power rating together. I would never drive high efficiency speakers with high power however so there are always exceptions to the rule. 

 

 

@realworldaudio 

as most of us have no hearing above 14kHz or so

How do you know this? My audiograms only measure from 250-8000Hz.

What is your experience with amp power?

good discussion here so far ...

my short answer is:

’all else equal, more power over less power -- but all else is never equal’

that’s where the fun begins

I use Pass XA30.8 to drive my 87db sensitive 4ohm Wilson Sabrinas. Room is not too large and 90% of the time the amp never leave class A (30 watts per channel). Match the amplifier power to  your speakers as well as your room, it’s not so much  the quantity but the quality that’s important.

 

My personal preference and priority is for lively sound at modest volume levels. This is more commonly achieved with tube amps than solid state.  My favorite tube types happen to be quite low in output, and I prefer amps that don’t rely on many tubes operating in parallel—fewer tubes sound more pure and clear to me.  This does mean I have to make do with lower power, but this is a minor compromise because the power I get from my amps is “sufficient” (Rolls Royce used to stay away from the numbers game by refusing to give a horsepower rating for their motors, and instead, they said its output was “sufficient”).  With my 99 db/w speakers, I get by with 6.5 watts per channel from a parallel single-ended 2a3 amp and 5.5 watts per channel from a pushpull 349 amp (my favorite amp).

First is sound quality.   If you don’t like the first watt, you won’t like more of them.   That’s not my quote, but I really liked it.

Second is synergistic.   It has to work well in my system (with my other components), not someone else’s, like the dealer’s…

Third is power.   More is always better.

Fourth is aesthetics.   It’s got to look good and have a high WAF.

Fifth is price.   I have to be able to afford it as I don’t want a new wife.

Sixth is new vs used.   I prefer new, but usually end up with well cared-for used.  (See Fifth as I get a better bang for my buck).

 

YMMV (your mileage may vary)…

Two experiences from me, the last one I can not explain. Comments welcome.

Frst & briefly: Amphion Argon 3 standmounts driven by a peachtree amp. I swapped the amp for a Krell amp of the same power. Result: tonnes of bass suddenly appears. I guess this is because the Krell amp was able to provide a lot of current when called on. I.e. it’s transient power was more.

More interestingly, due to a bizarre series of events I was able to try a second NAD C298 power amp in addition to my C298 driving KEF Reference 3 speakers (not a super tough load), this meant that I could use them as bridged mono blocks, and so went from 180W per channel to 600W, but with the same gain (this is switchable on the NADs), and no change in circuit design or parts quality.

 

The result of 3x more power was that everything just got more relaxed, more effortless, less shouty. I think I ended up listening louder, because it was just all so smooth. It was like my system had slipped on a smoking jacket and poured itself a brandy. Lovely. Not louder, no more base, yes a bit better stereo, but mainly just more effortless. I have no idea why this effect happens as the KEFs probably take only a couple of watts at normal listening levels.

At the risk of oversimplification (which this is) a power amp is essentially a modulated power supply. In that context the best amps* I've heard all have large linear power supplies. As regards the ultimate power needed, all things being equal, a good big amp will beat a good small amp, but in the real world where budget constraints apply, room size, speaker choice and listening level will influence choice.

* I haven't critically listened to any tube amps above 100 wpch.

My 45w Primaluna EVO 400i and my 35w Pathos TT Anniversary sound so much better than any HP amp I've tried on my Focal Scalla Utopia. For instance, they have more bass, more punch and more control than my 333w / ch Bryston 6BSST2, which ended up in my separate HT system. By chance, an Isotek Titan power block and Nordost Valhalla power cords help a lot in terms of "punch". Primaluna is now driving my Devore O/96s and the Pathos for the Scallas is definitely a keeper

One of the best systems I’ve heard had tube, 40x2 watts going to some Acoustat speakers with a couple of small subwoofers. With the lower bass removed from the main speakers, 40 watts was more than enough power.

The "high power" tube amp that I like a lot is the Synthesis A100 (rated at 100 wpc).  That amp runs tubes of my liking-KT66 in pushpull-so it is sort of the exception to what I generally like and dislike.  If someone truly needs much more power, even though I am a tube fan, I would suggest looking at solid state because, to me, many high powered tube amps sound hard and brittle (some call it "glare").  These days, solid state does not sound harsh or "grainy" (terms commonly applied to solid state in the past); to me they sound a touch lifeless at modest listening levels and are not quite as engaging (one's mind tends to wander instead of being pulled into the music).  There is no doubt that solid state can deliver very tight and punchy bass, but overall, it is still tubes for me.  I also don't have a particular preference for tube topology--I like some pushpull amps, single ended triode amps and output transformerless amps.

@curiousjim mentioned Acoustat. For years I used a pair of Hafler DH-220s running in bridged mode to power them and the RH Labs sub I have. This provided about 440wpc. Then a few years ago someone pointed out to me that electrostatics aren't exactly stable impedance and that the bridged mode was not an optimal set up. It was a simple enough experiment to change things by flipping the bridging switch and moving the speaker cables to a single channel on each amp. 

The difference in sound was astounding even though I was only providing 100wpc to the speakers! The detail and depth was greatly improved and the bass was still authoritative. I was amazed. (And my butt was sore from kicking myself for wasting all those years! 🙄)

The point I'm attempting to illustrate is that power is only one factor to consider. Compatibility and quality should also be carefully considered in your choice of amplification. BTW, I wound up with an ARC VS-110 which is about 110wpc and I'm happy as a clam. While it doesn't go to the subterranean depths of the solid state Haflers, it does everything else very, very well. 

Hope these thoughts help your hunt.

Happy listening...

Here's a real-life experience that, IMO, about sums this up:

I and a friend spent some serious seat-time with a pair of Aerial Acoustics 6T speakers (90 dB for 2.83 volts at 1 meter on axis; 4 ohms, 3 ohms minimum, low reactance; power requirement 25 watts minimum, >50 recommended) in a scheduled and well-orchestrated audition (same sound room; same acoustics; same day; minute or two between A & B listening sessions; same music; etc.). BTW: If you've got the dough and the right power source for these Aerial 6T, they are hard to beat, if that's even possible in their price range. The power source used for the first listening session was a MAC MC275 rated, conservatively, at 75 WATTS into 2 channels. Forget what the pre-amp used was but it, too, was a MAC. Minutes later, the MAC MC275 was swapped out for a MAC MA5200 rated, conservatively, at 100 WATTS into 2 channels. Within seconds (i.e.  you didn't have to listen long or hard), it was quite obvious the MC275 was able to make those Aerial sing! Did they sound better or even as good with the MAC MA5200? NO WAY! They still sounded very nice. However, the beefier power supply of the MAC MC275 and the current it could provide was immediately palpable. It's not he WATTS. It's the power supply.

It seems the closest thing to a perfect world of amp employment is

via Bi-Amping

Mono-blocks>bi-amp

Even though the majority of one’s listening is done at around the 5 watt mark, I’m a firm believer of having ample power for transients. I also believe the quality of those watts make a huge difference  as well. Having that head room and power even with highly efficient speakers make for a much better listening experience.  No straining, no clipping, ease of presentation. In my experience my Tannoys are 95 db efficient and I drive them with a 500wpc McIntosh amp. When I first got the amp I thought it would literally blow me out of the room, but that wasn’t my experience. I think I’d be hard pressed to go down in wattage. 

High, clean current is most important. Too often watts are way over stated by a manufacturer and then when hooked up they sound weak. As always, the only way to really know is to place an amp in your system and see how it sounds to your ears.

My Audio Research Ref 75SE sounds bigger and better than my 600 watt ss monoblocks on every speaker I've ever played them with.

I think for most people, enough power is about 30 watts but amplifier power is not a good basis for comparing two amplifiers.  

"watts are watts" is a fallacy.

Mono-blocks>bi-amp

That is generally my experience as well, though some solid state amps will sound worse when "bridged" to mono. With tube amps I’ve definitely heard substantial improvements going to mono. If the amp was designed to be a monoblock (not switchable), then you’re golden.

Having that head room and power even with highly efficient speakers make for a much better listening experience. No straining, no clipping, ease of presentation. In my experience my Tannoys are 95 db efficient and I drive them with a 500wpc McIntosh amp. When I first got the amp I thought it would literally blow me out of the room, but that wasn’t my experience. I think I’d be hard pressed to go down in wattage.

Yep, same here! Big Tannoys with a lot of quality power behind them => limitless dynamics, lifelike sound :)

I know my Tannoys can sound great with 25 - 35 Watts, I used to do that, but when you hit a need for power these amps won’t be able to deliver no matter their PSU design. Certainly, one could get through a lot of musical material before hitting a dynamic transient that’s going to either cause compression or hard clip on that lower power amp (yes, tube amps can hard clip too). But it’s there. Vinyl setups also have to content with higher playback power demands from feedback, warps and resonance issues - you try to mitigate this but it’s always there. More power freed me from these issues - and then I also noticed the other benefits of cleaner, lower distortion, and extended frequency range playback from the extra headroom. When you hit a huge dynamic swing, +10dB or more can happen very quickly, and while your 35 Watt amp could melt your ears off all day with with KISS (with no dynamic range) you’d really need 300 Watts to play that orchestral peak cleanly.

Post removed 

I do not like high efficiency speakers, because they usually have poor dynamic floor. It's a trade-off. Heavier speakers can get a lot better dynamic range from quiet listening to very LOUD.

@czarivey 

High efficiency loudspeaker usually have greater dynamic range than less efficient speakers, due to something called 'thermal compression', which is heating of the voice coil. As the coil heats up, its resistance goes up too. This is far more common with lower efficiency loudspeakers! Most solid state amps will thus put out less power. This can happen with individual bass notes, causing them to compress.

Its often more difficult to find higher power amplifiers that actually sound like music, although that problem is not as big now as it was 20 years ago.

Post removed 
Post removed 

Scott22

Great comment. Clear as mud to me as well. God Bless us poor guys!  But I think many people here have great contributions to a somewhat complicated issue. and i appreciate everyone's input. I have a low power tube amp that I really luv.... it's sounds so good.

And I always say... the most important person who listens and enjoys your system... is you!

Post removed 

The more the better. I have never heard a lesser power amp sound as good as a more powerful amp of the same design. Even high efficiency speakers sound better with more power. Don’t rob the dynamics of high efficiency low power.