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Early 70's watts vs. 80's watts

hopeless said:
The simplest answer is that the old receivers were designed to drive speakers and the newer stuff was meant to hit a number on the FTC test driving an 8 ohm resistor. Stuff in the 70s was far more expensive than the modern day stuff, had fewer channels, and fewer everything. Different level of expectation from the buying public as well.
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Boy, it sure was.

Using the website Dollar Times, I calculated how much the $399 I paid for my Yamaha CA-810 in 1979 would be worth projected forward to 2015 dollars.

Today, you'd have to fork over damn near $1,400 for that amp. Yikes. No wonder why my young college self worked so hard to afford it back then.

And as I recall, I got a bargain on closeout buying it for $399. I seem to recall retail being more like $479 at my HiFi shop, with a national retail average of $430 (from Classicaudio.com). Times change, so does the value of money and sometimes the quality of the goods.

Full retail average of $430 in 1977 when that amp was first introduced, would yield a 2015 price of $1,734.00.

Yep, stuff was a bit more pricey back then.
 
whoaru99 said:
Actually, you can't get the watts if the amp can't swing the voltage. Generally, audio amplifiers are voltage amplifiers, current simply follows the voltage and the load as much as it can.
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Kind of like when we swing 30,000 volts from our finger to the doorknob on a winter day, but don't die because we aren't moving any current? :)
 
hopeless said:
Impedance and more, you can't overlook capacitance, inductance, phase angles, and other nasties going on in a real dynamic speaker load. Like I said, it gets down to math. Yes, voltage and current are both involved in this "game." The speaker is going to ask for things that the amplifier has to be able to deliver. Some speakers ask a lot, some, not so much. Just narrowing it down to straight impedance however, really doesn't give a good look at what the amplifier really sees.

What happens if your amplifier can't deliver the current the speaker demands? You can answer sonically, mechanically, or mathematically.
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Yes, there are other factors, but as I understand it working just with the impedance curve is virtually always the worst case in terms of load.
 
whoaru99 said:
Yes, there are other factors, but as I understand it working just with the impedance curve is virtually always the worst case in terms of load.
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It can get plenty worse. Impedance defines the bulk of it, but other things step in at usually the worst possible moments...of course. Stereophile did a multi-issue rundown many years ago with a speaker engineer. I thought it was done pretty well.
 
BillyBatts said:
Boy, it sure was.

Using the website Dollar Times, I calculated how much the $399 I paid for my Yamaha CA-810 in 1979 would be worth projected forward to 2015 dollars.

Today, you'd have to fork over damn near $1,400 for that amp. Yikes. No wonder why my young college self worked so hard to afford it back then.

And as I recall, I got a bargain on closeout buying it for $399. I seem to recall retail being more like $479 at my HiFi shop, with a national retail average of $430 (from Classicaudio.com). Times change, so does the value of money and sometimes the quality of the goods.

Full retail average of $430 in 1977 when that amp was first introduced, would yield a 2015 price of $1,734.00.

Yep, stuff was a bit more pricey back then.
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I remember in high school just "knowing" that a good receiver and a good pair of speakers would run $600 ea. That was in that same timeframe. It became a goal in life.
 
kcbluesman said:
I'd like to know all three, please.
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The amplifier can current limit and "not go there", it can shut down if long enough to trip any protection circuit, or it can break.

Most will just "not go there" and sound pretty weak, especially in the bass.

As was mentioned..."It's the law." If it's not there, it ain't gonna happen. You can't get around it.
 
robgmn said:
Kind of like when we swing 30,000 volts from our finger to the doorknob on a winter day, but don't die because we aren't moving any current? :)
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Yeah, along the lines as well why 100 amps is enough current to supply a small town with power because it's coming in at 115kV transmission, yet 100 amps is only enough for a moderate-sized house because it's at 120/240V.
 
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hopeless said:
I remember in high school just "knowing" that a good receiver and a good pair of speakers would run $600 ea. That was in that same timeframe. It became a goal in life.
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True enough. Let's just look at that.

1978 (average of when I bought this gear) purchase of a Yamaha CA-810, two Optimus 10 speakers, Sanyo MicorProcessor Controlled Cassette Player, Sony Reel to Reel deck, Yamaha YP-D4 turn table with Ortofon MC Cart and a Sherwood Tuner. My Junior Year College System. Still have all that gear today thank goodness.

Total average retail for the above in 1978, $1,885

Today's adjusted dollar cost, $7,127 according to Dollar Times.

Damn. No wonder we usually just "dreamed" of this stuff back then. It was a lofty goal to purchase it. I worked like an animal all summer long during my high school and college breaks in construction to be able to buy all of that gear by my junior year.
 
But as a percentage of income the change wouldn't be very much at all. Plus the cost of electronics in real dollars has gone down pretty significantly. Think about the cost of computers for example.
 
kcbluesman said:
Sounds cool...but I have no idea what it means. I understand that an amp must be able to deliver the current required by the load...is this the gist of it?
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As I understand it, what he was communicating was that almost anything can be rated at "a hunnert watts" in some form or another, but without an adequate power supply to deliver the necessary amount of current, you have home theater receivers that are rated at "100 watts per channel" - one at a time - in a real world situation with multiple channels driven that 100 watts suddenly becomes 30 or 40 watts per channel. My original point about H-K was that their beefier power supplies meant that they delivered essentially the same power whether all channels were driven or just one.

It was always tough convincing people that an H-K receiver's 50 watts per channel was equivalent to the "hunnert watts" claimed by the Pioneer-Yamaha-Denons of the world.

Happy trails,
Larry B.
 
whoaru99 said:
I'm somewhat familiar high voltage/low current, low voltage/high current. But, pretty much all that you've said goes back to the part where I said, "Each must be in the appropriate measure, it's the Law". Preamps deliver very little current relative to a power amp because they're designed to drive high impedance, relatively speaking, in the manner of a voltage bridge, not a transfer of power. Which, as well, goes back to the point about the ability, or maybe lack thereof, to make apples to apples comparisons.

I think some people read what I wrote and assume it means I'm saying current is unimportant. Not much could be further from the truth. But, what I am saying is that current and voltage must be present in a defined relationship for power at any given load, it's the Law.
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Right, we are saying the same thing, so I won't beat a dead horse. Good explanation, kudos :thmbsp:
 
1tumbleweed said:
As I understand it, what he was communicating was that almost anything can be rated at "a hunnert watts" in some form or another, but without an adequate power supply to deliver the necessary amount of current, you have home theater receivers that are rated at "100 watts per channel" - one at a time - in a real world situation with multiple channels driven that 100 watts suddenly becomes 30 or 40 watts per channel. My original point about H-K was that their beefier power supplies meant that they delivered essentially the same power whether all channels were driven or just one.

It was always tough convincing people that an H-K receiver's 50 watts per channel was equivalent to the "hunnert watts" claimed by the Pioneer-Yamaha-Denons of the world.

Happy trails,
Larry B.
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It's tough to make any comparison that amounts to anything more than speculation without the published specs from both sides.
 
1tumbleweed said:
As I understand it, what he was communicating was that almost anything can be rated at "a hunnert watts" in some form or another, but without an adequate power supply to deliver the necessary amount of current, you have home theater receivers that are rated at "100 watts per channel" - one at a time - in a real world situation with multiple channels driven that 100 watts suddenly becomes 30 or 40 watts per channel. My original point about H-K was that their beefier power supplies meant that they delivered essentially the same power whether all channels were driven or just one.

It was always tough convincing people that an H-K receiver's 50 watts per channel was equivalent to the "hunnert watts" claimed by the Pioneer-Yamaha-Denons of the world.

Happy trails,
Larry B.
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It's tough to make any comparison that amounts to anything more than speculation without the published specs from both sides.
 
loubert said:
I SOOOO love this line!!!!!
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Me to. Although John was making some superb posts in this thread.
People fall for to much from the 70's like most of it was the best stuff ever made, and most everything else afterwards was poorly made. Absolute rubbish!

And although not an amp, I have two DVD players. One is a Sony DVP-NS999ES, and the other is a Pioneer DV-45A
The Sony has much better build quality, was more expensive, and built a few years after the Pioneer. The little 45A Mops the floor with the Sony! In every way, except it's build quality.

Can the same be said for many vintage units compared to supposedly lesser modern gear? YES!
 
1tumbleweed said:
As I understand it, what he was communicating was that almost anything can be rated at "a hunnert watts" in some form or another, but without an adequate power supply to deliver the necessary amount of current, you have home theater receivers that are rated at "100 watts per channel" - one at a time - in a real world situation with multiple channels driven that 100 watts suddenly becomes 30 or 40 watts per channel. My original point about H-K was that their beefier power supplies meant that they delivered essentially the same power whether all channels were driven or just one.

It was always tough convincing people that an H-K receiver's 50 watts per channel was equivalent to the "hunnert watts" claimed by the Pioneer-Yamaha-Denons of the world.

Happy trails,
Larry B.
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I don't miss the "hunnert watts" and 12" three-way days. However, I did thoroughly enjoy putting an h/k 330i against some monsters from Pioneer and Kenwood that were 165 and 180 "watts" and proceed to decimate them with 25 watts at very moderate listening levels. Bass and soundstage were huge differences, but even the highs were so much better defined and not harsh. This was around 1987-89. I loved when Consumer Reports electronic issue came out in the spring....lived for it.
 
whoaru99 said:
It's tough to make any comparison that amounts to anything more than speculation without the published specs from both sides.
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Bob Carver got his start exploiting this very thing. His infamous "Coffee Can" amplifier built to beat the McIntosh "tune up" tests, and used the fame to launch Phase Linear.
 
"Were receivers in this timeframe rated differently, with different standards"
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I believe the ratings are the same for the purposes of FTC. However I think the testing procedure has been relaxed. They now use a shorter duty cycle, 1/6 perhaps vs 1/3 back then. Both my 2001 Onkyo AVR and 1978 Realistic stereo receiver used the same spec. That is "Continuous RMS power at 8 ohms from 20 - 20,000 hz at X% THD, 2 channels driven.

There are other variables to consider though. Speakers driven with music are a far different load than an 8 ohm resistor feed a test tone.

One is the available current from the amp. Some (not all) newer amps and AVR's actually restrict current when the load dips to 4 ohms reducing the power it would have without current limitation by perhaps 1 db, Instead of increasing it enough to provide 2 db's more power. For a net difference of 3 db. So some 50 wpc amps could sound like a 100 wpc amp with speakers with a 6 or 4 ohm nominal impedance. The size of the power supply and heat sinking will give you an idea of the amps current capability.

Also there is peak power vs FTC ratings. Harmon Kardon and NAD, Perhaps others build some of their amps with 6 db's of headroom, while the average amp often has 1-2 db's headroom. This however should be taken with a grain of salt since IHF dynamic headroom is measured over just 10-20 ms. Still, we might get an extra 2-3 db's more power for music for longer periods from these rare amps. The size of the power supply and heat sinking relative to its FTC power rating will give you an idea of an amps reserve power.

Combine a high current (by today's standards anyway) amp with one with extra headroom, and we may find a 50 wpc amp that will take on a 150 wpc amp in the real world. Some of the extra headroom is derived from higher current.
 
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