2.4KW amp, anyone?

[Phelonious Ponk]

It is impossible the sound can "stay the same" from when you have the volume control maxed out and turn it back to half way. This simply means that your volume control is stuck at full-on or you have a severe hearing problem. I see no other explanation other than a vivid imagination.

I'm slowly coming around to the realization that Frank doesn't quite speak English, not as the rest of us do. When he says it "sounds the same," while I'm not at all sure what he does mean, he doesn't mean it sounds the same. Or at least I'm willing to give him that benefit of the doubt.

Tim

 

[Phelonious Ponk]

I'm not saying I don't enjoy head banging on occasion Frank, especially in the company of friends and copious amounts of Red Horse Beer. It's not about that. There's a reason for acoustics Frank, it's intelligibility. An enclosed room will ring at sufficient amplitude. The reverberation will eventually turn everything into one load roar. Live or amplified, it'll happen. Just because something is live it doesn't mean it automatically sounds good.

Yeah...and when he says "amplitude" and "intelligibility," and "reverberation" they don't quite mean what the rest of us mean by those words either. Or so it would seem...

Tim

 

[Phelonious Ponk]

Oh, and Frank? Give me my Gibson Original Jumbo, a heavy flat pick and my voice. We'll step into a tiled bathroom, or even a small kitchen. I will overpower you. Intelligibility will break down. Your ears will admit defeat. You will pray for a volume control. This is just one more example of what must be either a brilliant imagination or a lack of real experience, but you seem to think you can tweak your way out of the physical world.

Tim

 

[fas42]

What I think you probably are getting is a system that is designed to be limited, so you can crank it all the way up without damaging it and without getting too deep into clipping.

Tim

And that is exactly right. I have already stated that several times: because the system is "all in a box" the designers, smart fellows that they were, adjusted sensitivities and gain so that you couldn't grossly overdrive the output stages. Unlike conventional separate pre-amps. I have noted that current HTIABs in the local electrical, which ARE bits of rubbish in many ways compared to the Philips, so people are partially right there, have the same behaviour as my HT, only worse. Most of them barely get above a whisper, even with their sticky tape blurb screaming "500 watts!!", etc.

So it doesn't clip: it can thermally shutdown, I have done that on odd occasions. Where it was badly lacking in its stock form was that it would compress badly, dynamics would collapse very quickly and distortion would go through the roof. Just like a lot of other stuff out there. That's where the big difference is after my fiddling: as Roger is very well aware, the subjective impression of dynamics and intensity goes up big notches when the system does all the good things right ...

Frank

 

[fas42]

Oh, and Frank? Give me my Gibson Original Jumbo, a heavy flat pick and my voice. We'll step into a tiled bathroom, or even a small kitchen. I will overpower you. Intelligibility will break down. Your ears will admit defeat. You will pray for a volume control. This is just one more example of what must be either a brilliant imagination or a lack of real experience, but you seem to think you can tweak your way out of the physical world.

Tim

See, you're just going silly now, Tim. The point of good audio is to reproduce what was recorded at something equal or close to the volume what was experienced in the recording environment, that is the ultimate point of the exercise. People over and over again state that they can't, or it's impossible even theoretically to get real life dynamics into the listening room. So you jump completely to the other side of the room and say that live sound will send you deaf in 10 seconds flat in some pointless environment.

So now we will step our way nicely up to sensible appraisals. Most people can handle a real piano being played in their living room, without running screaming out of the house with their hands over their ears. Playing reasonably well recorded solo classical piano pieces I and my wife, who plays and we have one of those potentially dangerous items in the living area, agree that replay at about 36/40 is correct volume for that instrument. It sounds like being a metre away from a piano when a metre away from the speakers, and the volume still sounds correct for that instrument being played in the living room, at the other end of the house. Does that help people get the picture?

FRank

 

[Whatmore]

I'm slowly coming around to the realization that Frank doesn't quite speak English, not as the rest of us do. When he says it "sounds the same," while I'm not at all sure what he does mean, he doesn't mean it sounds the same. Or at least I'm willing to give him that benefit of the doubt.

Tim

He speaks fluent 'strine just like the rest of us

 

[fas42]

He speaks fluent 'strine just like the rest of us

Gedonya, mate!! Need a bit of sticking up for me, 'round here ...

Frank

 

[c1ferrari]

Is there a dynamometer for audio systems, Don?

1 HP = 746 W

Just in case someone needed to know that...

I'm gonna need about 1 horsepower a side...
Well, what the heck -- let's make it 4 HP, total
We're talkin' Albert Porter headroom, here, hehe

 

[Whatmore]

Perhaps someone more technical than I can answer this question: what sort if power would a non class-D amp draw in order to output 2.4kw? In guessing 50% efficiency is probably ambitious. Given this, is it actually possible for a domestic mains to supply enough power to run an amp of this power?

 

[fas42]

Perhaps someone more technical than I can answer this question: what sort if power would a non class-D amp draw in order to output 2.4kw? In guessing 50% efficiency is probably ambitious. Given this, is it actually possible for a domestic mains to supply enough power to run an amp of this power?

Yes, if you're not trying to use the amp for arc welding a la Mark Levinson, or at a less spectacular level, as a room heater via a dummy load. In other words, it is not intended for it to output this level on a continuous basis but rather to handle the power demands of reproducing normal music, say an average of 600 watts if driven really hard. So no problem with a "proper" power supply in the amp ...

So John Atkinson would be disappointed with it. But it should do a damn fine job of playing music ...

Frank

 

[Phelonious Ponk]

Frank, we don't have time for this. You need to be building a 2400 watt amp and I need to be knitting a hat from chocolate yarn...oh, wait a minute, I see it's a 600 watt amp now...are we playing with ratings Frank? I think we all assumed you were talking about RMS?

Tim

 

[Whatmore]

Frank, we don't have time for this. You need to be building a 2400 watt amp and I need to be knitting a hat from chocolate yarn...oh, wait a minute, I see it's a 600 watt amp now...are we playing with ratings Frank? I think we all assumed you were talking about RMS?

Tim

But 600W RMS is about 850w Peak (I think). That's a fair way short of 2.4kw

 

[Phelonious Ponk]

But 600W RMS is about 850w Peak (I think). That's a fair way short of 2.4kw

Yeah, Frank probably intends to build to the IDLV (Intergalactic Dark Lord of Ventriloquism) wattage standard. I think my hat's pretty safe.

Tim

 

[fas42]

Frank, we don't have time for this. You need to be building a 2400 watt amp and I need to be knitting a hat from chocolate yarn...oh, wait a minute, I see it's a 600 watt amp now...are we playing with ratings Frank? I think we all assumed you were talking about RMS?

Tim

It would help a great deal, Tim, if you acquired some electrical knowledge, and actually read my posts reasonably carefully, before commenting so vigorously and aggressively. A lot of the time it appears that you form a snap opinion about where someone is coming from, and from then on just keep reacting to the image you have formed in your mind about them, rather than really reading what they say and then thinking calmly and rationally about the point they are attempting to make.

For a start, Tim, try and work out the difference between RMS and continuous ...

Frank

 

[terryj]

A lot of the time it appears that you form a snap opinion about where someone is coming from, and from then on just keep reacting to the image you have formed in your mind about them, rather than really reading what they say and then thinking calmly and rationally about the point they are attempting to make.

For a start, Tim, try and work out the difference between RMS and continuous ...

Frank

You reckon peoples opinion of you on this forum is a SNAP opinion?

You mean none of us have read your posts in the past and have not formed an opinion based on them?

Hmm, the opinion just got worse I'm afraid....

AND, you 'lecture' tim on what he needs to learn in audio??

Sheesh

 

[fas42]

A piece from Wikipedia that perfectly encapsulates what I'm talking about:

The term "Music Power" has been used in relation to both amplifiers and loudspeakers with some validity. When live music is recorded without amplitude compression or limiting, the resulting signal contains brief peaks of very much higher amplitude (20 dB or more) than the mean, and since power is proportional to the square of signal voltage their reproduction would require an amplifier capable of providing brief peaks of power around a hundred times greater than the average level. Thus the ideal 100-watt audio system would need to be capable of handling brief peaks of 10,000 watts in order to avoid clipping[citation needed] (see Programme levels). Most loudspeakers are in fact capable of withstanding peaks of several times their continuous rating (though not a hundred times), since thermal inertia prevents the voice coils from burning out on short bursts. It is therefore acceptable, and desirable, to drive a loudspeaker from a power amplifier with a higher continuous rating several times the steady power that the speaker can withstand, but only if care is taken not to overheat it; this is difficult, especially on modern recordings which tend to be heavily compressed and so can be played at high levels without the obvious distortion that would result from an uncompressed recording when the amplifier started clipping.

An amplifier can be designed with an audio output circuitry capable of generating a certain power level, but with a power supply unable to supply sufficient power for more than a very short time, and with heat sinking that will overheat dangerously if full output power is maintained for long. This makes good technical and commercial sense, as the amplifier can handle music with a relatively low mean power, but with brief peaks; a high 'music power' output can be advertised (and delivered), and money saved on the power supply and heat sink. Program sources that are significantly compressed are more likely to cause trouble, as the mean power can be much higher for the same peak power. Circuitry which protects the amplifier and power supply can prevent equipment damage in the case of sustained high power operation.

More sophisticated equipment usually used in a professional context has advanced circuitry which can handle high peak power levels without delivering more average power to the speakers than they and the amplifier can handle safely.

In other words, I'm talking about something like the "ideal 100 watt amplifier" ...

And note that people who build systems that need to deliver real sound levels know the "smart" way of going about it ...

Frank

 

[Phelonious Ponk]

It would help a great deal, Tim, if you acquired some electrical knowledge, and actually read my posts reasonably carefully, before commenting so vigorously and aggressively.

Educate me, then, Frank. What does this mean --

In other words, it is not intended for it to output this level on a continuous basis but rather to handle the power demands of reproducing normal music, say an average of 600 watts if driven really hard.

-- if it doesn't mean that you don't intend to build an amp that would deliver continuous power (RMS) of 2.5kw, but one that would deliver continuous power of, say, and average of 600 watts if driven really hard? Help me acquire the electrical knowledge I need to understand how 2500 watts is really only 600 watts when driven really hard. Why would I assume you had been talking about RMS? Well, Frank, because from entry-level midfi up, that's the standard. So you were talking about 2400 watts peak power then?

A lot of the time it appears that you form a snap opinion about where someone is coming from, and from then on just keep reacting to the image you have formed in your mind about them, rather than really reading what they say and then thinking calmly and rationally about the point they are attempting to make.

Oh it has hardly been a snap judgement, Frank. It didn't take reading too many posts to understand where you fall in the audiophile food chain, but there has been a wealth of confirmation.

Tim

 

[Phelonious Ponk]

So you're talking about peak power, or the marketing departments euphemism, "music power?" You're talking about this, i assume, given that you emphasized it...

Thus the ideal 100-watt audio system would need to be capable of handling brief peaks of 10,000 watts in order to avoid clipping

So, by this standard, you're talking about building a 24 watt amp? That's a bit different, I suspect, than what most of us thought we we're discussing, Frank. And your jokes about naming it something like "Krill," etc., encouraged that misunderstanding.

Tim

 

[fas42]

if it doesn't mean that you don't intend to build an amp that would deliver continuous power (RMS) of 2.5kw, but one that would deliver continuous power of, say, and average of 600 watts if driven really hard? Help me acquire the electrical knowledge I need to understand how 2500 watts is really only 600 watts when driven really hard. Why would I assume you had been talking about RMS? Well, Frank, because from entry-level midfi up, that's the standard. So you were talking about 2400 watts peak power then?

As I said previously, it appears that you don't actually read what other people say in their posts; from my initial post:

Also, the aim is not to try to do something macho like making it capable of delivering these high levels of power continuously. No, the idea is for it to be able to gracefully deliver the power to meet the needs of real music playback, the sort of thing that might even keep Basspig happy!

I can see we are now going to have a big debate about the word "continuous", so I'll try and head it off at the pass: continuous to me means continuous, so if Krell says their amp can put out 2400W RMS, "continuously" into 2 ohms, I'll take them at their word. I'll rig up a nice big monster dummy load of that impedance, pretty easy to do, and stick it in a room at that power output, and close the door for a couple of hours. Oh, dear, it's shutdown because of thermal overload! Oh dear, not very continuous to me, or are you going to squib on that word, Tim ...

Now if I wanted my amp to do that, I would have to hook it up to multiple house spurs, roughly quadruple the transformer and other power supply requirements, same again for the heat sinks, add fans and other cooling paraphenalia, have it weigh half a ton and make sure it cost 10 times what it would otherwise cost. But it would satisfy you and JA! I'll leave it to others to decide which version of the amp they would prefer ...

Frank

 

[Phelonious Ponk]

As I said previously, it appears that you don't actually read what other people say in their posts; from my initial post:


I can see we are now going to have a big debate about the word "continuous", so I'll try and head it off at the pass: continuous to me means continuous, so if Krell says their amp can put out 2400W RMS, "continuously" into 2 ohms, I'll take them at their word. I'll rig up a nice big monster dummy load of that impedance, pretty easy to do, and stick it in a room at that power output, and close the door for a couple of hours. Oh, dear, it's shutdown because of thermal overload! Oh dear, not very continuous to me, or are you going to squib on that word, Tim ...

Now if I wanted my amp to do that, I would have to hook it up to multiple house spurs, roughly quadruple the transformer and other power supply requirements, same again for the heat sinks, add fans and other cooling paraphenalia, have it weigh half a ton and make sure it cost 10 times what it would otherwise cost. But it would satisfy you and JA! I'll leave it to others to decide which version of the amp they would prefer ...

Frank

You're right, Frank. I either missed that sentence or it lost its meaning in subsequent references to satisfying Bass Pig, or being comparable to a Krell. No need to quibble over the meaning of continuous, though, we can just go with the meaning of "music power" you quoted from Wikipedia, and now we all know what you're talking about. You're talking about building a 24 watt amp that will totally satisfy Bass Pig and compare favorably to a Krell. You're going to exceed the Phillips by 4 watts per channel. Handy that your existing speakers will be adequate, eh?

I look forward to your progress reports.

Tim