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#160042 - 05/08/05 10:36 AM Smoke and Mirrors?  
Trumpy  Offline


Member
Joined: Jul 2002
Posts: 8,211
SI,New Zealand
A lot of people that I've come across in my travels have bought Stereo gear, IMO because of the marketing hype.
Statements like 150W PMPO(Peak Music Power Output), or the newer term used here in various pamphlets, AVPO (Average Voltage Power Output).
People are being sucked in left, right and centre.
Mainly because most of the sales idiots won't let you see the actual Specs Sheet.
I bet that the last time the statement "But what's the Total Harmonic Distortion at that output?" would have been asked back in the 70's.
People are dumb now with respect to (dare I say) Hi-Fi gear, all of the marketing people have made it so that all of thier terms mean little or nothing to do with the gear that they sell.
It's made to sound flash, but expect no extra perfomance from it.
Let's dis-regard OFC cables and stuff like that and concentrate on the systems themselves.
I read in a bit of literature here and apparently there is a new way of getting better sound out of a Power Amp, better High Frequencies and even better Low Frequencies.
Simple, you put the (of course) Toroidal Transformer on a 3 degree slant, to the Chassis.
I'd never thought of this before.
I could have been a multi-millionaire, by now. [Linked Image]
What is your take on all this bunkum, guys?.


Let's face it, these days if you're not young, you're old - Red Green grin

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#160043 - 05/08/05 11:24 AM Re: Smoke and Mirrors?  
gfretwell  Offline


Member
Joined: Jul 2004
Posts: 9,056
Estero,Fl,usa
These days virtually any solid state amp chip will produce better sound than most people can hear and do it for the price of a case of beer. You are really paying for the plastic box it is in, the controls and the display.
The biggest chunk of the price is hype.

Listen to them and buy what you like.


Greg Fretwell

#160044 - 05/08/05 06:48 PM Re: Smoke and Mirrors?  
pauluk  Offline
Member
Joined: Aug 2001
Posts: 7,520
Norfolk, England
The hype and pseudo-science has been going on for some years now. Those "peak music power" and other dubious ratings seem to be what attract many people. Even if the ratings are genuine and consistent, so many just don't realize that the difference between, say, a 50W amplifier and a 75W one is not all that great anyway, and could easily be wiped out by differences in speaker efficiencies on different setups.

On the distortion, I have to laugh at some of the advertising and misguided beliefs. That amp which boasts 0.005% THD must be twice as good as the one listing 0.01% right? Nevermind the fact that nobody will hear 0.01% distortion in the first place, of that the speakers will add to that manyfold.

They sure like gimmicks too. Remember when those cheap "stack" units in the 1980s all had to have a row of LEDs to indicate power output? So many were just numbered 1 through 9 giving a meaningless reading. Others tried to look technical by putting dB labels on them, but with no reference level and absolutely no calibration so that a 3dB difference on the indicator could actually be almost anything in reality!

Oh yes, and a few months back I saw a little "mini-HiFi" unit in town which proudly proclaimed that it had a "Variable Attenuation Control System" incorporated. Sounds so much more impressive than just calling it a volume control, doesn't it? [Linked Image]


[This message has been edited by pauluk (edited 05-08-2005).]


#160045 - 05/08/05 10:35 PM Re: Smoke and Mirrors?  
dereckbc  Offline
Member
Joined: Oct 2003
Posts: 156
Tulsa, OK
I was quite an audiophile in my younger days, even designed amps, still have some equipment. Here is one to remember Quad or 4-channel sound. Fell on it's butt. Then some guru at Dolby re-spun it to what we now have in it's evolution of 3.1, 4.1, 5.1, and now 7.1 surround sound.

As for me, I still use a couple of McIntosh MC-352's and four Klipch Corner horns. Call it old fashioned, but it blows anything away you can buy today.

Heck if it fails I have enough wood to build a boat and a couple of good anchors.


#160046 - 05/13/05 07:30 AM Re: Smoke and Mirrors?  
RSmike  Offline
Member
Joined: Nov 2002
Posts: 134
Holland, MI USA
Tell me the B+ and B- rails in the amp and I'll tell you the best possible RMS output into the speaker load.... It's all about the math folks.

I use to work at a 'electronics place' while at university. One day I hauled out my signal generator, dummy loads, and O-scope. Oddly enough the RMS ratings on the amps were actually right across a pretty wide range. I was impressed.

The only product that I have ever seen rated properly has been Sony audio equipment. Their typical rating is x Watts RMS at x ohms from xHz to xKhz with x%THD.

I would still recommend a low THD. Your ears might not be able to hear it but your speakers will have to deal with it. THD means heat to speaker coils.

Some of these new car amps will drive loads down to 1 ohm or less and keep dumping out the current. Basically pulling more watts out of the amp.

As far as home amps go. If you are spending anything in the US$500 range for a home amp then you are probably getting what's stamped on the amp in RMS power. (ie. Sony, JVC, Denon, Kenwood, etc)

Peak power is something I just love. Couple a marketing degree with an engineering degree and that amplifier can be as big as you want it to read....

"electro-mechanical Ether coupling system".....speakers!! Sign me up for marketing.

Dereckbc, one day a few years back I walked by the trash bin at work. Inside was a McIntosh amp totally stripped. My heart skipped a beat. The only thing left that even caused me to look was the nameplate on the front in that nice raised script. My friend, who was with me at the time, took the nameplate and put it on his Mac PC. At least a portion of it got to live on... People are stupid...amps are so easy to fix.

RSlater,
RSmike


#160047 - 05/15/05 04:43 AM Re: Smoke and Mirrors?  
Trumpy  Offline


Member
Joined: Jul 2002
Posts: 8,211
SI,New Zealand
Some good comments here.
One thing I must say is the fact that having "results" without a reference to any particular quantity, like dBW or anything else that is a scientific amount just goes to show just how bogus these terms are.
It's just like the old days with the CB Antenna's with ratings that no-one could believe (or attain).
40 Watts of Talk power, try and top that!. [Linked Image]


Let's face it, these days if you're not young, you're old - Red Green grin

#160048 - 05/15/05 05:45 AM Re: Smoke and Mirrors?  
pauluk  Offline
Member
Joined: Aug 2001
Posts: 7,520
Norfolk, England
Quote
It's just like the old days with the CB Antenna's with ratings that no-one could believe (or attain).

Yep, like the 3 ft. long base-loaded whips advertising some silly gain figure such as 8dBd, although most of them (if they used a reference at all [Linked Image] ) used dBi -- That extra couple of dB using an isotropic as the reference makes it look so much better. [Linked Image]

P.S. For you non-RF guys, an isotropic is a theoretical point-source antenna which radiates equally well in all directions. A plot of points of equal field strength would yield a sphere. By contrast, the standard vertical dipole radiates equally well in all compass directions, but with reduced power upward and downward. The field-strength plot would resemble a very flat and wide donut with the antenna standing in the hole.



[This message has been edited by pauluk (edited 05-15-2005).]



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