What is a powerful amp?

[plastic penguin]

I agree with Chebby.

The Hegel boys might as well shut your eyes. How many times recently have we heard from Andrew and a couple of others about how powerful the 360 is. That doesn't impress me at all. What would be far more impressive is how it plays at low/idling levels.

I've no issue with the Hegelians, or their dialectric.

I'm not antithetical to any of their electricals.

I was agreeing with "Just showing that watts can be cheap". Wasn't necessarily having a pop at the hegel boys, but it is the overriding comment from the 360. To coin a Clarkson phrase I'm not impressed just by POWER!

Right from day one, because I lived in a terraced house I always had to play at reasonable levels, and even now in a semi-detached, we have to keep the neighbours sweet - and make sure my daughter's sleep isn't disturbed during school terms.

An amp that's adept at low levels is good. One that can't is shown the door pretty swiftly.

 

[drummerman]

I agree with Chebby.

The Hegel boys might as well shut your eyes. How many times recently have we heard from Andrew and a couple of others about how powerful the 360 is. That doesn't impress me at all. What would be far more impressive is how it plays at low/idling levels.

Most of the high end stuff I've heard (Roksan Caspian Monoblocs, Bryston to name just two) were wonderful when cranked to the rafters, but low settings they were complete and utter s###e.

Indeed. Unfortunately a lot of transistor amplifiers exhibit more distortion in the first few watts than further up, rising again towards clipping.

Valve amplifiers usually don't.

 

[davedotco]

I agree with Chebby.

The Hegel boys might as well shut your eyes. How many times recently have we heard from Andrew and a couple of others about how powerful the 360 is. That doesn't impress me at all. What would be far more impressive is how it plays at low/idling levels.

Most of the high end stuff I've heard (Roksan Caspian Monoblocs, Bryston to name just two) were wonderful when cranked to the rafters, but low settings they were complete and utter s###e.

Indeed. Unfortunately a lot of transistor amplifiers exhibit more distortion in the first few watts than further up, rising again towards clipping.

Valve amplifiers usually don't.

This is very true, especially of old fashioned Class AB designs.

The Behringer A500, a 120 wpc power amp of some notoriety comes to mind here. The design is simple, basic and cheap but relies on preset resistors to optimise distortion, usually, given it's market, at higher levels.

The result is an amplifier that sounds very decent when driven quite hard but can sound a bit coarse and grainy at low levels. Not all A500s react the same though, some seem rather better than others in this respect and may account for the wildly split opinions on this product.

That said, if you need this kind of power and are going to use it, the A500 at just £140 remains something of a steal.

 

[matt49]

Folks might find this thread from the Harbeth User Group forum interesting, and especially the video in post #9.

The conclusion: the power demands of different types of music vary massively, and the most demanding types of music (heavy electronica, crescendi in large orchestral works) make shockingly big demands of an amp.

 

[matt49]

No responses? Nobody looked at the video?

Shame ...

 

[DocG]

Read the posts, but iPad keeps freezing when trying to watch the movie. I'll have another try tomorrow... Goodnight, folks!

 

[matt49]

It's worth using headphones for the video.

*drinks*

 

[Andrewjvt]

No responses? Nobody looked at the video?

Shame ...

Wont play the video file but ill have a listen tomorrow on my pc. Buts thanks the forum is interesting

 

[Gaz37]

With most things written on this post from all the others but in my case changing from the same make amp 150w to the 250w amp made an overall improvement to the sound from the top end and mostly the bass

so you are saying if i was to swap evo 50 a to a 100a and play the music at same volume level, the SQ will be better?

Going back to my originan question: does more power mean louder or better overall performance too?

More power always means louder, but not always better performance (either from the amp or speaker side). Certanly no speaker performed worse for having more amplifier headroom, but many (if not most) will be bottlenecked by the amp. Whole different matter is if we can't hear the limitation (in peaks) or if we think the deteriorated sound comes off as improvement and higher fidelity. Distortion in certain forms can come off as richness, texture, musicality etc.

Two possible conclusions:

1) Watts are cheap, better have more than less.

2) If you think the Earth is a disc on top of whales, better stick to less watts and enjoy musicality. Less is more. *bomb* *angel*

specs on my amp says 55 watts @8 ohms and 85 watts @4ohms and specs on my speakers state recommended amplificantion 30W-120w into 8ohms unclipped progs.

so that makes me undestand that my amp has enough power to drive the speakers. Now i have 2 questions.

a) what would have happened if my amp was less than 30watts and vice versa more than 120w?

b) what ever is unclipped programme?

< 30W it means you can't go loud enough for typical listening needs with that particular loudspeaker without pushing the amp into clipping. If you go into clipping, you may blow a tweeter or other drivers.

> 120W it means you can go loud enough for typical listening needs with that particular loudspeaker and have sufficient headroom without stressing the amp to its limits. The first to hit its limits will be the speaker when the amp pushes 120W.

< 30W vs > 120W the later will go louder with cleaner sound with that particular loudspeaker.

My B&W 600s (86db) recommend an amp of 30-100watts yet my NAD 3020 (20watts) can drive them to well above normal listening levels easily, in fact anything past 10 o,clock on the volume dial is uncomfortably loud, even on low level (-10db) 12 o' clock is too loud.

So 20 watts can easily be more than adequate for normal & even very loud listening

 

[hybridauth_Facebook_664715932]

Folks might find this thread from the Harbeth User Group forum interesting, and especially the video in post #9.

The conclusion: the power demands of different types of music vary massively, and the most demanding types of music (heavy electronica, crescendi in large orchestral works) make shockingly big demands of an amp.

very interesting video.

Thsnks

 

[matt49]

My B&W 600s (86db) recommend an amp of 30-100watts yet my NAD 3020 (20watts) can drive them to well above normal listening levels easily, in fact anything past 10 o,clock on the volume dial is uncomfortably loud, even on low level (-10db) 12 o' clock is too loud.

So 20 watts can easily be more than adequate for normal & even very loud listening

It's interesting to see what Alan Shaw says about speaker manufacturers' amp power recommendations (see the thread linked to in my post #54 above). Basically, manufacturers know they should recommend higher-powered amps, but they don't do it because they think it'll scare off customers who own low-powered amps.

 

[chebby]

It's interesting to see what Alan Shaw says about speaker manufacturers' amp power recommendations (see the thread linked to in my post #54 above). Basically, manufacturers know they should recommend higher-powered amps, but they don't do it because they think it'll scare off customers who own low-powered amps.

Or his customers will go and buy someone else's speakers.

 

[davedotco]

My B&W 600s (86db) recommend an amp of 30-100watts yet my NAD 3020 (20watts) can drive them to well above normal listening levels easily, in fact anything past 10 o,clock on the volume dial is uncomfortably loud, even on low level (-10db) 12 o' clock is too loud.

So 20 watts can easily be more than adequate for normal & even very loud listening

It's interesting to see what Alan Shaw says about speaker manufacturers' amp power recommendations (see the thread linked to in my post #54 above). Basically, manufacturers know they should recommend higher-powered amps, but they don't do it because they think it'll scare off customers who own low-powered amps.

Indeed. It is likely that the 'differences' heard when auditioning budget amplifiers is actually the way they react to being overdriven/clipped. As the video shows, the right program material will cause clipping at seemingly quite modest levels.

A couple of points about the early 3020, one of the reasons for it's success was it's fine control when overdriven, distortion certainly increased but it was benign, not at all nasty so simply made the amp sound louder. These amps had the famed 'soft clipping' feature, which was odd as the 3020 needed it much less than other budget amps of the day which behaved far worse when driven hard!

Furthermore it was designed in the days well before the CD with it's 2 volt output became the norm, so is, by modern standards very sensitive. A volume setting of 10 o'clock will be pretty loud but the amp will be well into clipping by about 11 o'clock, once again, the volume control giving no indication of the actual power being delivered.

 

[matt49]

It's interesting to see what Alan Shaw says about speaker manufacturers' amp power recommendations (see the thread linked to in my post #54 above). Basically, manufacturers know they should recommend higher-powered amps, but they don't do it because they think it'll scare off customers who own low-powered amps.

Or his customers will go and buy someone else's speakers.

That was implied.

I guess the practice of recommending underpowered amps is pretty much universal among speaker manufacturers. You wouldn't want to be the one to step out of line.

 

[Craig M.]

My B&W 600s (86db) recommend an amp of 30-100watts yet my NAD 3020 (20watts) can drive them to well above normal listening levels easily, in fact anything past 10 o,clock on the volume dial is uncomfortably loud, even on low level (-10db) 12 o' clock is too loud.

So 20 watts can easily be more than adequate for normal & even very loud listening

The ear mistakes distortion for loudness, which is why your amp sounds 'loud'. My experience of more than enough power is that your system doesn't sound louder as the volume rises, it seems bigger - for want of a better word. You see it all the time on here - "my amp drives my speakers louder than I can bear", that's because it is shouting and has lost control.

 

[davedotco]

My B&W 600s (86db) recommend an amp of 30-100watts yet my NAD 3020 (20watts) can drive them to well above normal listening levels easily, in fact anything past 10 o,clock on the volume dial is uncomfortably loud, even on low level (-10db) 12 o' clock is too loud.

So 20 watts can easily be more than adequate for normal & even very loud listening

The ear mistakes distortion for loudness, which is why your amp sounds 'loud'. My experience of more than enough power is that your system doesn't sound louder as the volume rises, it seems bigger - for want of a better word. You see it all the time on here - "my amp drives my speakers louder than I can bear", that's because it is shouting and has lost control.

This is very true.

When someone makes a real, serious upgrade to their system, they often ten to play louder than before, mainly because of the improved headroom and lower distortion.

They do not notice that this is happening though, it often takes the reaction of a third part, a neighbour maybe, to point this out. The low distortion inherent in many active systems catch a lot of people out too, they are so easy to listen to at high levels as they do not sound loud.

To be fair though, the early Nad 3020 amplifiers did tend to "shout" more politely than most.

 

[Vladimir]

With most things written on this post from all the others but in my case changing from the same make amp 150w to the 250w amp made an overall improvement to the sound from the top end and mostly the bass

so you are saying if i was to swap evo 50 a to a 100a and play the music at same volume level, the SQ will be better?

Going back to my originan question: does more power mean louder or better overall performance too?

More power always means louder, but not always better performance (either from the amp or speaker side). Certanly no speaker performed worse for having more amplifier headroom, but many (if not most) will be bottlenecked by the amp. Whole different matter is if we can't hear the limitation (in peaks) or if we think the deteriorated sound comes off as improvement and higher fidelity. Distortion in certain forms can come off as richness, texture, musicality etc.

Two possible conclusions:

1) Watts are cheap, better have more than less.

2) If you think the Earth is a disc on top of whales, better stick to less watts and enjoy musicality. Less is more. *bomb* *angel*

specs on my amp says 55 watts @8 ohms and 85 watts @4ohms and specs on my speakers state recommended amplificantion 30W-120w into 8ohms unclipped progs.

so that makes me undestand that my amp has enough power to drive the speakers. Now i have 2 questions.

a) what would have happened if my amp was less than 30watts and vice versa more than 120w?

b) what ever is unclipped programme?

< 30W it means you can't go loud enough for typical listening needs with that particular loudspeaker without pushing the amp into clipping. If you go into clipping, you may blow a tweeter or other drivers.

> 120W it means you can go loud enough for typical listening needs with that particular loudspeaker and have sufficient headroom without stressing the amp to its limits. The first to hit its limits will be the speaker when the amp pushes 120W.

< 30W vs > 120W the later will go louder with cleaner sound with that particular loudspeaker.

My B&W 600s (86db) recommend an amp of 30-100watts yet my NAD 3020 (20watts) can drive them to well above normal listening levels easily, in fact anything past 10 o,clock on the volume dial is uncomfortably loud, even on low level (-10db) 12 o' clock is too loud.

So 20 watts can easily be more than adequate for normal & even very loud listening

I bet it's clipping like mad but NAD has that soft clipping circuit so your speakers or the amp don't blow up and the distortion isn't harsh on the ears. You can buy a small chip amp from ebay for $20 and your jaw will drop how loud it can drive speakers and it barely has 10W in it. Remember the big and loud ghettoblaster boomboxes of the 80's? Speakers no more than 5W and amp 3W, but they sure went loud.

 

[MajorFubar]

The ear mistakes distortion for loudness, which is why your amp sounds 'loud'.  My experience of more than enough power is that your system doesn't sound louder as the volume rises, it seems bigger - for want of a better word.  You see it all the time on here - "my amp drives my speakers louder than I can bear", that's because it is shouting and has lost control.

I see where you're coming from but I don't think that's more than partly true. It wouldn't matter how much control it had, anything above 90db is going to be unbearably loud in an average living room, which is not particularly difficult to achieve under normal conditions. I can't think of a time I've listened to a really powerful amp blasting out 90db+ in an average-sized living room and fully appeciated how controlled the unbearably loud music sounded compared to the same era-damaging volume from a lower-powered amp.

 

[MajorFubar]

The ear mistakes distortion for loudness, which is why your amp sounds 'loud'.  My experience of more than enough power is that your system doesn't sound louder as the volume rises, it seems bigger - for want of a better word.  You see it all the time on here - "my amp drives my speakers louder than I can bear", that's because it is shouting and has lost control.

I see where you're coming from but I don't think that's more than partly true. It wouldn't matter how much control it had, anything above 90db is going to be unbearably loud in an average living room, which is not particularly difficult to achieve under normal conditions. I can't think of a time I've listened to a really powerful amp blasting out 90db+ in an average-sized living room and fully appeciated how controlled the unbearably loud music sounded compared to the same era-damaging volume from a lower-powered amp.

 

[hybridauth_Facebook_664715932]

Folks might find this thread from the Harbeth User Group forum interesting, and especially the video in post #9.

The conclusion: the power demands of different types of music vary massively, and the most demanding types of music (heavy electronica, crescendi in large orchestral works) make shockingly big demands of an amp.

i have seen the video a couole of times, now i am a bit confused. I am sure the harbeth guy said that on their specs,for those particular speakers, recommended amplification 50-150W. However those amps were pumping 400+ W constantly, would that not be detrimental to the speakers?

 

[davedotco]

Language can be difficult in technical matters if it is not precise. 'Continuous' is often used to describe power when in fact average or rms would be a better option.

In the video clip the amplifiers continuously show peak wattage of extremely high values in excess of 500 watts, peaks by their nature are a transient phenomena and although they may happening continuously, ie one peak after another, this is not the same as 'continuous' or average power which is, effectively, steady state.

The music being played was descibed as being of wide dynamic range, perhaps in the region of 40dB. The average power will therefore be some 20dB below the peaks which reached 600-700 watts, so around 6-7 watts average. Even when playing less dynamic material, the average power will still be well inside the limits of the speaker.

This is why very high powered amplifiers, when driven unclipped but at very high levels pose little threat to compedent speakers, even those with a modest rating. Back in the day I used my Phase Linear 400, in excess of 200wpc with my Spendor BC1 with its 30 watt rating with no problems whatsoever.

 

[matt49]

Folks might find this thread from the Harbeth User Group forum interesting, and especially the video in post #9.

The conclusion: the power demands of different types of music vary massively, and the most demanding types of music (heavy electronica, crescendi in large orchestral works) make shockingly big demands of an amp.

i have seen the video a couole of times, now i am a bit confused. I am sure the harbeth guy said that on their specs,for those particular speakers, recommended amplification 50-150W. However those amps were pumping 400+ W constantly, would that not be detrimental to the speakers?

I think we need to get away from the idea that the manufacturer's amp power recommendation (which is only a recommendation after all) represents a technically accurate spec. It doesn't. The speakers won't fry or distort if you put 151W through them, or even 500W for that matter.

Alan Shaw makes the point that he actually designs the speakers to draw considerably more than the specified max of 150W. As I say, the 50-150W specification isn't a technically correct spec: it's intended to give the buyer a rough sense of what amp power will work well with the speakers.

In fact, that doesn't seem to be exactly true either. Shaw admits that the lower level will be inadequate to drive the speakers in some circumstances (playing demanding music loud in a large room), and that 100W would be a better minimum figure. But if he specified 100-500W that'd scare off potential buyers, who'd assume they'd need an expensive heavyweight amp to drive them.

DON'T BELIEVE THE SPECS. *diablo*

 

[iceman16]

Does distortion usually "harm" an amp or speakers be either minor or major?

 

[davedotco]

Does distortion usually "harm" an amp or speakers be either minor or major?

Very possibly.

Driving a speaker with a heavily clipped signal from an overdriven amplifier can be dangerous, Such a signal is virtually a squarewave with a power that might be higher than the rms output of the amplifier. Furthermore, the voice coil may be driven and held outside the magnetic gap (the flat, top of the squarewave), no longer subject to the cooling effect of the airflow and the magnet assembly, the coil can burnout in a split second.

Even worse, some amplifiers produce a small but significant DC offset when heavily into clip, again this forces the coil out of the gap and causes burnout. Of couse amplifiers driven hard for long periods may overheat, if the amplifier is not adequately protected the components in the amplifier may well be working outside their safe operating area and actually burn out.

These are of course at the extremes of amp/speaker behaviour, but any dealer will tell you 'monday morning' stories of blown speakers and customers saying they were not playing that loud and the amplifier is less powerful than the speaker rating etc, etc.

So perhaps not that 'extreme' after all!

 

[Gaz37]

With most things written on this post from all the others but in my case changing from the same make amp 150w to the 250w amp made an overall improvement to the sound from the top end and mostly the bass

so you are saying if i was to swap evo 50 a to a 100a and play the music at same volume level, the SQ will be better?

Going back to my originan question: does more power mean louder or better overall performance too?

More power always means louder, but not always better performance (either from the amp or speaker side). Certanly no speaker performed worse for having more amplifier headroom, but many (if not most) will be bottlenecked by the amp. Whole different matter is if we can't hear the limitation (in peaks) or if we think the deteriorated sound comes off as improvement and higher fidelity. Distortion in certain forms can come off as richness, texture, musicality etc.

Two possible conclusions:

1) Watts are cheap, better have more than less.

2) If you think the Earth is a disc on top of whales, better stick to less watts and enjoy musicality. Less is more. *bomb* *angel*

specs on my amp says 55 watts @8 ohms and 85 watts @4ohms and specs on my speakers state recommended amplificantion 30W-120w into 8ohms unclipped progs.

so that makes me undestand that my amp has enough power to drive the speakers. Now i have 2 questions.

a) what would have happened if my amp was less than 30watts and vice versa more than 120w?

b) what ever is unclipped programme?

< 30W it means you can't go loud enough for typical listening needs with that particular loudspeaker without pushing the amp into clipping. If you go into clipping, you may blow a tweeter or other drivers.

> 120W it means you can go loud enough for typical listening needs with that particular loudspeaker and have sufficient headroom without stressing the amp to its limits. The first to hit its limits will be the speaker when the amp pushes 120W.

< 30W vs > 120W the later will go louder with cleaner sound with that particular loudspeaker.

My B&W 600s (86db) recommend an amp of 30-100watts yet my NAD 3020 (20watts) can drive them to well above normal listening levels easily, in fact anything past 10 o,clock on the volume dial is uncomfortably loud, even on low level (-10db) 12 o' clock is too loud.

So 20 watts can easily be more than adequate for normal & even very loud listening

I bet it's clipping like mad but NAD has that soft clipping circuit so your speakers or the amp don't blow up and the distortion isn't harsh on the ears. You can buy a small chip amp from ebay for $20 and your jaw will drop how loud it can drive speakers and it barely has 10W in it. Remember the big and loud ghettoblaster boomboxes of the 80's? Speakers no more than 5W and amp 3W, but they sure went loud.

It certainly isn't "soft clipping" because that is turned off. lol

As you say it may be shouting but if so it's doing so it's in a very nice, polite & melodic fashion that doesn't sound at all harsh or strained.

It's currently playing Enya with the volune at around "5 o'clock" and I can hear it quite clearly in the next room (1930s house with proper brick walls not plasterboard)

So I still maintain that less than 30w can be perfectly adequate