2.4KW amp, anyone?

[fas42]

But I can get hard when someone I don't fully trust fails to clearly state the objectives and commit to the deliverables of his project. Even worse is when they avoid the standards that are common and well-understood within the organization and expect, instead, everyone to follow their own, much more vague standard. Unless they have clearly articulated a reason for that behavior, I find myself suspecting that they are just trying to avoid being held to a standard at all. You've made a lot of very wild claims around here, Frank. Did you expect to try to demonstrate them without scrutiny?

I'm glad you don't work for me too. Enjoy your project. Since I've taken my edible hat out of play, I'll watch it all unfold with no personal investment and a lot less commentary going forward.

Tim

You're bloody hopeless, Tim! I throw an idea out in the ring, to get tossed around a bit by people, to get some feedback, some sense of the value to others, some balanced commentary. You, on the other hand, come across like a wounded bull, expecting me to come out with complete design spec and business plan by the end of my second post. Methinks you should have gone and worked for a bit with TI back in the 80's ...

"Wild claims"?? If I had spent vast amounts of money and said similar things, would you have been just as aggressive?

"clearly articulated"?: good example of the pot calling the kettle back ...

And, of course, you still haven't followed that link: talk about talking through your hat, the part where you should have already chomped away a bit of it ...

Frank

 

[steve williams]

Play nicely boys....

 

[mep]

You're bloody hopeless, Tim! I throw an idea out in the ring, to get tossed around a bit by people, to get some feedback, some sense of the value to others, some balanced commentary.

I don’t know what this means when you say “some sense of value to others.” Why would your “idea” have any value to anyone on this forum? Very high powered amplifiers made by very reputable companies already exist and are on the market to be bought. No one even knows what it is you are really proposing as 2400 some-kind-of-watts has now morphed into 600 some-kind-of-watts. You haven’t even explained what class of operation your amp would operate under. In the end, when all is said and done, many of us are confident that more will be said than ever done with regards to an amplifier being built by you. My point is that the audiophile market is not crying out for an amp to be built by you. I see no niche that you are proposing to fill that hasn’t already been filled by real companies making real products with real warranties. This amplifier story should have started with “Once upon a time…”

 

[fas42]

I don’t know what this means when you say “some sense of value to others.” Why would your “idea” have any value to anyone on this forum? Very high powered amplifiers made by very reputable companies already exist and are on the market to be bought.

http://www.whatsbestforum.com/showthread.php?3771-2.4KW-amp-anyone&p=60357&viewfull=1#post60357. Something that does this at less than silly pricing:

ME: As regards 84dB speakers, the point is that people have these for their qualities of reproduction, not to do HT, but still would like to get realistic levels of sound during music listening. Which won't happen if the power amp is not up to it. An example: MBL 101Es, the watermelon speakers, 82dB sensitivity, they handle 500 watts RMS, 2200 peak; and you don't want to use MBL's amps ...

No one even knows what it is you are really proposing as 2400 some-kind-of-watts has now morphed into 600 some-kind-of-watts.

http://www.whatsbestforum.com/showthread.php?3771-2.4KW-amp-anyone&p=60966&viewfull=1#post60966 and http://www.whatsbestforum.com/showthread.php?3771-2.4KW-amp-anyone&p=61233&viewfull=1#post61233

You haven’t even explained what class of operation your amp would operate under.

http://www.whatsbestforum.com/showthread.php?3771-2.4KW-amp-anyone&p=61233&viewfull=1#post61233

My point is that the audiophile market is not crying out for an amp to be built by you. I see no niche that you are proposing to fill that hasn’t already been filled by real companies making real products with real warranties.

I would just suggest you reread the number of posts already on this thread about having dynamic headroom. Again, it's about voltage swing, not massive amps. To put it bluntly, the amp will never go into clipping, unless you want to ruin your speakers/hearing ...

Frank

 

[Phelonious Ponk]

You're bloody hopeless, Tim! I throw an idea out in the ring, to get tossed around a bit by people, to get some feedback, some sense of the value to others, some balanced commentary. You, on the other hand, come across like a wounded bull, expecting me to come out with complete design spec and business plan by the end of my second post. Methinks you should have gone and worked for a bit with TI back in the 80's ...

"Wild claims"?? If I had spent vast amounts of money and said similar things, would you have been just as aggressive?

"clearly articulated"?: good example of the pot calling the kettle back ...

And, of course, you still haven't followed that link: talk about talking through your hat, the part where you should have already chomped away a bit of it ...

Frank

I stopped by a very nice little audio store after work this evening. Asked about the power of the amps there. RMS. Every one. Nobody mentioned "average power." And all the speakers were rated XX watts, RMS to XXX watts, RMS, into Xohms. And that was no surprise. In my 40 years in audio, that almost all I've ever seen. RMS. Now, I must admit, I've seen a few very cheap low end products rated "peak power" and a couple of ads for similar stuff talking about "music power," but I don't think I've ever seen a commercial audio product reference "average power." And if I did, I wouldn't be able to do anything useful with it, even after I followed your link, Frank, because my frame of reference...audio's frame of reference, is RMS. I'm not an EE, so I can't convert your average power to something everyone understands -- RMS. But you are an EE and you should be able to make that conversion. Why don't you just do it and end the confusion?

"Average power?" May as well measure you car's engine in zebra power.

Tim

 

[DonH50]

To be fair, technically RMS (root-mean-squared) power is not a unit. P = V * I so it can be average, instantaneous, peak, real, imaginary etc. but Vrms * Irms is not Prms (RMS^2 = MS). That has not stopped virtually every manufacturer (and probably a few undergrad texts for all I know) from using "RMS power" in their specifications to indicate when voltage and/or current is RMS.

I did look at power ratings briefly on-line and found some used W RMS and some did not.

Is there an IHF definition of "dynamic headroom"? I seem to recall one but do not remember the timeframe.

 

[tony ky ma]

Play nicely boys....

No wonder it don't like a normal topic in DIY because Steve moved it to DIY, no shows no pictures just talk, I did a monster tube amp on wheel because it over 200 lb but the out put only 50+50 W
tony ma

 

[DonH50]

Now, there's a post worthy of DIY!
Thanks Tony - Don

 

[Phelonious Ponk]

To be fair, technically RMS (root-mean-squared) power is not a unit. P = V * I so it can be average, instantaneous, peak, real, imaginary etc. but Vrms * Irms is not Prms (RMS^2 = MS). That has not stopped virtually every manufacturer (and probably a few undergrad texts for all I know) from using "RMS power" in their specifications to indicate when voltage and/or current is RMS.

I did look at power ratings briefly on-line and found some used W RMS and some did not.

Is there an IHF definition of "dynamic headroom"? I seem to recall one but do not remember the timeframe.

Don, you seem to have some knowledge. Can you help me with what "average watts" means?

Tim

 

[fas42]

I don't think I've ever seen a commercial audio product reference "average power." And if I did, I wouldn't be able to do anything useful with it, even after I followed your link, Frank, because my frame of reference...audio's frame of reference, is RMS. I'm not an EE, so I can't convert your average power to something everyone understands -- RMS. But you are an EE and you should be able to make that conversion. Why don't you just do it and end the confusion?

"Average power?" May as well measure you car's engine in zebra power.

Tim

From the McIntosh MC2W Owner's Manual, Specifications:

Power Output
2000 watts into an 8, 4 or 2 ohm load is the minimum sine
wave continuous average power output. The output RMS
voltage is:
126.5V across 8 ohms
89.5V across 4 ohms
63.3V across 2 ohm

From the mbl Technical Data download:

mbl 9011 mb
Peak Pulse Power
Mono
Stereo (2? ?? ?)

5 000 W
1 200 W
Rated Power
Mono/Stereo 8?
4?
2?

440 W / 130 W
840 W / 220 W
1390 W / 340 W
Output Voltage
max.
100 / 50 V peak
Output current max. 50 A peak

But I'm sorry, these are obviously rather low quality units, so we'll ignore what the manufacturers believe is relevant ...

And you still haven't followed the link ...

Frank

 

[fas42]

To be fair, technically RMS (root-mean-squared) power is not a unit. P = V * I so it can be average, instantaneous, peak, real, imaginary etc. but Vrms * Irms is not Prms (RMS^2 = MS). That has not stopped virtually every manufacturer (and probably a few undergrad texts for all I know) from using "RMS power" in their specifications to indicate when voltage and/or current is RMS.

I did look at power ratings briefly on-line and found some used W RMS and some did not.

Is there an IHF definition of "dynamic headroom"? I seem to recall one but do not remember the timeframe.

Thanks for chipping in, Don, it's hard work getting through to some people ...

Frank

 

[fas42]

No wonder it don't like a normal topic in DIY because Steve moved it to DIY, no shows no pictures just talk, I did a monster tube amp on wheel because it over 200 lb but the out put only 50+50 W
tony ma

Very nicely done, Tony, I guess it's a SET ...

Frank

 

[JackD201]

Okay, to end the specs thing I propose the set of measurements used by BHK Laboratories. I don't know how to fully correlate the figures to what I hear but the measurements are some of the most exhaustive supplied. I'm posting a link to a 220wpc amplifier I own and have lent it for demonstration with Infinity IRS IIIs vs a 380wpc Halcro. WBF members Jadis and Mullard88 were in attendance. The friends of the IRS owner drove the Halcro so hard trying to keep up that the Halcro clipped and fried some panels. I guess watts aren't the whole story. The link below shows BHK's independent testing results in rated voltage and current along with max clipping voltage and max clipping current corresponding to watts among others. This is the "cheapest" Lamm. My original pair is on loan to the local Magico dealer so I bought another pair. That is the level of confidence I have in this unit. That's 220wpc but capable of almost 45amps at 1ohm peaks (app. 2000watts). Now before someone quips that this is theoretical because I can't draw that much current from the wall, Remember our line voltage is 230V but is typically 235V and yes I have dedicate 20A lines for each of them. It remains theoretical in the sense that I have never played music loud enough to need that kind of power.

http://www.lammindustries.com/PRODUCTS/m22spec.html

Build it and have it independently tested, lots of people will come. No product, no business plan Frankie. This is a case where the chicken always comes before the egg.

 

[DonH50]

Pasted from Mathcad (a math program used to get pretty integral signs):


Note that the peak-to-average ratio in music is around 17 dB, meaning you need 50 times the average power to avoid clipping the peaks. For movies, I have seen as high as 30 dB, and other research (which I recall but cannot site off-hand; you want it, you find it) indicates live music may be similar. 30 dB is a factor of 1000, meaning you need 1000 W to not clip if your average power is only 1 W. Assuming your speakers (and ears) can take it...

Aside: You can think of the integrals as calculating the area under the curve of power over time.

 

[fas42]

Okay, to end the specs thing I propose the set of measurements used by BHK Laboratories. I don't know how to fully correlate the figures to what I hear but the measurements are some of the most exhaustive supplied. I'm posting a link to a 220wpc amplifier I own and have lent it for demonstration with Infinity IRS IIIs vs a 380wpc Halcro. WBF members Jadis and Mullard88 were in attendance. The friends of the IRS owner drove the Halcro so hard trying to keep up that the Halcro clipped and fried some panels. I guess watts aren't the whole story. The link below shows BHK's independent testing results in rated voltage and current along with max clipping voltage and max clipping current corresponding to watts among others. This is the "cheapest" Lamm. My original pair is on loan to the local Magico dealer so I bought another pair. That is the level of confidence I have in this unit. That's 220wpc but capable of almost 45amps at 1ohm peaks (app. 2000watts). Now before someone quips that this is theoretical because I can't draw that much current from the wall, Remember our line voltage is 230V but is typically 235V and yes I have dedicate 20A lines for each of them. It remains theoretical in the sense that I have never played music loud enough to need that kind of power.

http://www.lammindustries.com/PRODUCTS/m22spec.html

Build it and have it independently tested, lots of people will come. No product, no business plan Frankie. This is a case where the chicken always comes before the egg.

Starting to look reasonable, Jack. And again note, no use of the word RMS wrt power. Only trouble is, again that weasel word "continuous": does that mean 60 secs, 5 mins, 10 minutes, 24 hours? Thermal shutdown is going to kill a lot of "continuous" ratings, especially on a hot day, is the air conditioner going, on and on it can go ...

Interesting that the Halcro clipped. That's why you need headroom ...

The unit will be built when there's some locked in agreement of what's needed, some time, and some money. The interest is looking good so far, but time and especially money will be the biggest issues ...

So my question to you now is: why aren't you using that instead of the tubed Lamm? Precise reasons, please, like Tim would require ...

Frank

 

[fas42]

Yes, Don, as stated in your post , "what we see reported most often as "RMS power" is actually the average power using RMS voltage ... into a defined purely resistive load" looks good to me ...

Thanks,

Frank

 

[JackD201]

They just match my preferred speakers better. I do have a pair of ML1.1 90wpc lamm amps and use them for mid-high duties when the mood strikes me. They work wonderfully with VR-5s and Unifield 3s in moderately sized rooms upto about 30 to 40 sq/m. My room however is, as you recall, closer to 80sqm. I need the extra power to get my midbass drivers going properly (which is all I use them for BTW). Up top I use the full class A ZNFB hybrid model. Now why these two together? Input sensitivities are identical.

As for Steve's ML3s which I am smitten with. Reason A: I can't afford them. Reason B: When in the future I can, the speakers have to be made for them. Initial designs are there already actually but it is a project on the back burner. AVS has been a busy guy lately.

 

[steve williams]

I think (bias included) there has been a speaker made for them which you heard you know where

 

[Mark (Basspig) Weiss]

Seeing this is a DIY discussion, then I'll assume it's a hobby thing. From the start, it sounded like a thought experiment into a possible commercial product.

High crest factor is possible, but if you insist on doing it in class A topology, that kind of power level will require special mains hookups that only very few dedicated audiophiles will bother with. If you designed a class H amplifier, this would be possible and quite pedestrian on a 15A residential outlet.

I work military airshows and probably the loudest things there are the ordinance explosions. The scream of fighter jets in afterburner wasn't quite what I expected. It was loud, but not deafeningly. I used to work in a paper mill and we had a steam whistle in there for the evac alarm. That was quite loud. About 140dB possibly.

 

[JackD201]

I think (bias included) there has been a speaker made for them which you heard you know where

Hahahahaha. Yes indeed! Other factors not related in the least to sonics are at play Steve. There are personalities I have no wish of dealing with ever again locally. How does the saying go? Fool me twice shame on me? You get the picture