Is this acurate?

[Overdose]

So the general concensus so far is that you don't need much more than about 30W? Good luck with that I say.

This may be suitable for dynamically compressed recordings, but not with wider dynamic ranges. It's the transient swings that are the problem.

A quick web search will tell you all you need to know about clipping.

Overdose, that's why I asked you how many dbs at 1 meter your speakers are putting out on the loudest peaks at the loudest volumes you ever listen at? And how many dbs is that at your listening position?

It's impossible for me or anyone else to say how many watts someone needs - even on the most dynamic of recordings - without knowing their speaker efficiency, the maximum peak db level they listen at and how far they sit from their speakers.

The extra headroom inherent in more powerful amplifiers is to enable transient swings to be dealt with effectively. Like I said, use a 30W amp if it suits and you feel comfortable, but a more powerful amplifier is always a safer bet. If you want to draw analogies, it's not about outright speed, but acceleration and braking, both of which are done with less effort with larger engines in a vehicle.

 

[BigH]

Why do many amps sound best when the volume control is around 10-11 oclock? That is only a few watts if that. As I said the Rega did not sound good at 12 oclock and I did not push it any further.

 

[hoopsontoast]

It not so much about watts which is a pretty poor measurement anyway. It is really about how it sounds at the level you want to listen at. What speakers do you have, what room size, what musical source?

http://www.whathifi.com/forum/your-system/an-odd-collection

 

[CnoEvil]

I'm very technologically challenged but I would hazard a guess that the figures given are largely accurate. However, I think it's difficult to state categorically whether a higher or lower power rating leads to better sound. My Accuphase E-560 only puts out 30 W per channel in Class A but the sound is easily smoother and more powerful than the amp it replaced, which was a Jeff Rowland Continuum 500, rated at 500 Wpc.

Your comment has almost slipped by unnoticed....and unless one has personally experienced a well designed 30W SS Class A, it's difficult to grasp just how powerful they can be. Not all 30W are created equal.

 

[BigH]

It not so much about watts which is a pretty poor measurement anyway. It is really about how it sounds at the level you want to listen at. What speakers do you have, what room size, what musical source?

http://www.whathifi.com/forum/your-system/an-odd-collection

Haha, you got the wrong person I was asking the OP.

 

[hoopsontoast]

It not so much about watts which is a pretty poor measurement anyway. It is really about how it sounds at the level you want to listen at. What speakers do you have, what room size, what musical source?

Haha, you got the wrong person I was asking the OP.

Oops my bad :help:

 

[oldric_naubhoff]

The extra headroom inherent in more powerful amplifiers is to enable transient swings to be dealt with effectively. Like I said, use a 30W amp if it suits and you feel comfortable, but a more powerful amplifier is always a safer bet. If you want to draw analogies, it's not about outright speed, but acceleration and braking, both of which are done with less effort with larger engines in a vehicle.

only that this is not really the matter of more powerful amp but how capable power supply it has. coincidentally more powerful AB amps will have better sorted power supplies (otherwise they wouldn't really be more powerful) than low power AB amps, due to cost restraints of the latter. just to put things into perspective compare innards of a entry level Marantz integrated amp and a Luxman or Accuphase 30W class A integrated. in both cases you'll get roughly 30W pc but dynamic swings and bass will be handled totally differently.

I'd happily live with a pair of output devices per channel in my room. and I believe that most people would too. but I'd like to mate that pair of transistors with ca. 1KVA mains transformer and +100KuF capacitance. all you really need to handle dynamic peaks is wide mains voltage rails (few amps have) and enough energy reservoir to pump amps into tough loads. and yes, most of the time you don't even use 1W pc of power.

 

[lindsayt]

The extra headroom inherent in more powerful amplifiers is to enable transient swings to be dealt with effectively. Like I said, use a 30W amp if it suits and you feel comfortable, but a more powerful amplifier is always a safer bet. If you want to draw analogies, it's not about outright speed, but acceleration and braking, both of which are done with less effort with larger engines in a vehicle.

The car engine analogy does not apply well to amps and speakers. Completely different moving a 1.5 tonne vehicle via combustion and mechanical means to moving a speaker cone weighing a few grammes via electro-magnetic means. Or if we're going to use a car analogy we need to come up with 2 cars where one of them is 50 times heavier and 50 times less aerodynamic than the other.

The important specification in an an amplifier in controlling a bass cone at levels below clipping is not the maximum power rating, but the damping factor which depends directly on the output impedance of the amp. It's possible that you could have a lower powered amp with a higher damping factor than a higher powered one. In this example the lower powered amp would have more control over the bass cone, leading subjectively to a tighter, less woolly bass.

And then you have how the amplifier reacts to impedance swings, inparticular impedance dips. Again, it's possible that a lower powered one could react better than a higher powered one.

Having said that, as a sweeping generalisation, valve amps with output transformers tend to have lower damping factors than high powered solid state amps and such valve amps tend to cope less well with low impedance speakers.

However in my system, with my highly efficient speakers where I have never come close to clipping with any of my amps, it's my 8 watt valve amp that sounds more dynamic than my 80 watt solid state one. I'm not sure why that is? Maybe it's because the valve amp is better at low level details, maybe because it overshoots, maybe because the class A zero feedback design results in a more dynamic sound than class AB with some feedback? Who knows?

With my speakers for my volume tastes, 8 watts is already plenty of power for me. Remember, my EV speakers are about 50 times more efficient at turning electrical energy into sound than your AVI speakers. So 8 watts into my speakers is the equivalent of 400 into yours. And 30 watts into mine would be the equivalent of 1500 watts into yours. Would you agree with me if I said that 1500 watts through your speakers would be overkill - quite literally?

 

[Overdose]

The car engine analogy does not apply well to amps and speakers. Completely different moving a 1.5 tonne vehicle via combustion and mechanical means to moving a speaker cone weighing a few grammes via electro-magnetic means. Or if we're going to use a car analogy we need to come up with 2 cars where one of them is 50 times heavier and 50 times less aerodynamic than the other.

I believe you and another forum member started down that route. The context is the same though, more power equals better control and for Oldric, it is implied that a more powerful amplifier will have a more capable power supply and all that it entails.

 

[hoopsontoast]

I believe he was impyling that most higher power amps tend to have higher spec power supplies as they need them for the higher power.

Most Lower power amps tend to be cheaper, and integrated for example (not including valves) so tend to be comprimised in this area.

Low powered amps with decent power supplies like class A amps, such as Sugden A21, Luxman/Accuphase or some of the MF models for example have relatively low power but very well designed power supplies and likely to do very well with lower impedance loads.

 

[john dolan]

A 50 watt Krell would drive tough speakers better than a 500 watt classD amp.Not all watts are created equal.

 

[Overdose]

A 50 watt Krell would drive tough speakers better than a 500 watt classD amp.Not all watts are created equal.

How did you come to that conclusion?

 

[john dolan]

The krell doubles its power 8ohm 50 watts 4ohm 100 watts 2 ohm 200 watts 1 ohm 400 watts now try that with a classD into tough speakers see how you go.

 

[Overdose]

The krell doubles its power 8ohm 50 watts 4ohm 100 watts 2 ohm 200 watts 1 ohm 400 watts now try that with a classD into tough speakers see how you go.

Yes, but which Krell amp and which class D amp are you refering to?

 

[john dolan]

KSA 50 v Belcanto ref 1000 try them both into killer speakers see which amp laughs and which curls up its toes and dies.

 

[Overdose]

KSA 50 v Belcanto ref 1000 try them both into killer speakers see which amp laughs and which curls up its toes and dies.

I see. So do these manufacturers make more powerful amplifiers, or are these considered the pinnacle and no further power required? No, of course not. Perhaps you need to tell Krell and others that they are wasting their time with anything more powerful?

The reason is that sometimes this level of power is not enough, so my advice would be to get an amplifier with suitable headroom, particularly if you are a frequent upgrader. Why limit future speaker choices to need to match your existing amp limitations, unless you feel the need to upgrade the amp as well.

 

[BigH]

KSA 50 v Belcanto ref 1000 try them both into killer speakers see which amp laughs and which curls up its toes and dies.

I see. So do these manufacturers make more powerful amplifiers, or are these considered the pinnacle and no further power required? No, of course not. Perhaps you need to tell Krell and others that they are wasting their time with anything more powerful?

The reason is that sometimes this level of power is not enough, so my advice would be to get an amplifier with suitable headroom, particularly if you are a frequent upgrader. Why limit future speaker choices to need to match your existing amp limitations, unless you feel the need to upgrade the amp as well.

Yes of course Krell make more powerful amps like the KSA 100, in the KSA50 review it said that he would prefer the KSA100 for some speakers. Yes the Krell can go down lower Ohms than the Belcanto which is limited to 2Ohms. Not sure that is all about driving speakers though.

"There is almost enough power to drive a pair of Apogee Scintillas at their ohm setting—though I'd prefer at least the Krell KSA-100."