Why are Watts not Watts?

[Ishmael]

Once again I am awe struck by how good vintage electronics are. We have been listening to a recent find, unrestored Sansui 2000A, through our restored Bose 601 series I speakers (wow did it make a difference moving these speakers from the garage into our listening room and placed as the manual advised). I also have a nice 90s Yamaha receiver that has 50 watts per channel and decided to compare the two receivers. There was no comparison, there was a loss in detail, in the immediacy of the music, even the bass was down. How can this be? The Sansui has 35 watts yet the Yamaha has 50 watts and was a poor second? We have had this happen serveral times, the new Sony 90 watt per channel receiver in the garage system was replace by our Pioneer SX-737 with only 35 watts per channel, less than half the power, but with twice the music. This is true even with vintage gear, but to a lesser degree. The SX-737 got move from the bedroom system by an even older Pioneer SX-6000, which with only one additional watt, 36 watts vrs. 35 watts, sounded better. This at least I can understand as from Hifiengine specs the SX-6000 has a significantly higher damping factor than the SX-737, 65 vrs. 40. Is it as simple as the lift test? The Yamaha can be lifted by one hand the Sansui no. Is it just big heavy transformers or is something else happening here? I welcome your thoughts and observations.

 

[davidb1]

Specs in the 70's were more complete. RMS was shown with both channels driven across the entire power bandwith, ie 20-20K or thereabouts.
Newer specs are often 1 channel driven at 1Khz.

 

[Pandovski]

35W? 50W? 90W? Are those headphone amplifiers?

 

[62caddy]

Specs in the 70's were more complete. RMS was shown with both channels driven across the entire power bandwith, ie 20-20K or thereabouts.
Newer specs are often 1 channel driven at 1Khz.

This is news to me. Are you saying the FTC has relaxed its power rating requirements?

I understand however that manufacturers of car audio systems are exempt from the FTC rating standards of 1974 thus are allowed to get away with the most outrageous power rating claims.

 

[Ishmael]

Actually none of the older gear has been re-capped yet, so they are all equally aged. As to power is power, we once had a 150 watt Music Fidelity integrated amplifier bought new and when we couldn't get it to sound as good as the bought new Creek 5350 SE it had replaced at 90 watts per channel we went listening and replaced it with a 50 watt per channel Naim Nait 5 which was twice as musical as the Music Fidelity and better than the Creek. Now pre-amp in these could make a difference the Music Fidelity and Naim having active while the Creek had a passive pre-amplifier-in fact in all cases anything you change in a system makes a difference. However, we have listened to different Naim amplifiers passing through the same per-amplifier and you can hear a difference, whether there is that much of a difference in the parts making the power could come into play if you jump to rasing the price by a factor of 10, but just doubling the price wouldn't seem to change the parts that much, though again we could hear the differene and power almost doubled.

 

[62caddy]

WATTS IS WATTS - period.

You are assuming wrong your situation in that it has to do with power - that is utter nonsense.

It has more to do with age than anything. Also, there is a pre-amp involved, built in to these receivers, and that is where your difference maybe heard.

Have any been recapped? If so, there is your difference. The 737 needs a recap at least.

Agreed.

Unless all operational characteristics are confirmed as being completely up to spec of all units, it's not a valid comparison.

Apples & oranges- pure and simple.

 

[Ishmael]

Hmm, savage morning, actually I do understand the 1 watt theory, having driven Klipschorn speakers with only a watt, 10 watts would have blown out the windows (a really good headphone amplifier would have worked). Sorry if you don't get low watt electronics, we have found that big power does not mean better music, but really good equipment large or small powered does.

 

[davidb1]

FTC allows more than one set of specs. You don't have to give the full specs to be legal.
The advice about recapping is quite valid as well.
To learn more about specs see old issues of Stereo Review and Stereophile. They often published truly complete specs including tone burst response and square wave response. Tone burst response shows how accurately an amplifier matches the original signal on a quick transient.

 

[62caddy]

Actually none of the older gear has been re-capped yet, so they are all equally aged. As to power is power, we once had a 150 watt Music Fidelity integrated amplifier bought new and when we couldn't get it to sound as good as the bought new Creek 5350 SE it had replaced at 90 watts per channel we went listening and replaced it with a 50 watt per channel Naim Nait 5 which was twice as musical as the Music Fidelity and better than the Creek. Now pre-amp in these could make a difference the Music Fidelity and Naim having active while the Creek had a passive pre-amplifier-in fact in all cases anything you change in a system makes a difference. However, we have listened to different Naim amplifiers passing through the same per-amplifier and you can hear a difference, whether there is that much of a difference in the parts making the power could come into play if you jump to rasing the price by a factor of 10, but just doubling the price wouldn't seem to change the parts that much, though again we could hear the differene and power almost doubled.

No disrespect- that would be like saying why did the original water pump go bad on a 1990 Bentley but it's still good a 1990 Corsica with the same mileage?

The effects of age will vary from one manufacturer to another & one component to another. Even identical components will have different aging characteristics- due to different types of use, frequency of use, environmental conditions and a host of other factors.

 

[jsisk]

This is news to me. Are you saying the FTC has relaxed its power rating requirements?

I would say that it is more of the manufacturers finding a way around it.

Here are the 1981 specs for my Pioneer SX-D7000. Back then, they only advertised the output at which all other advertised specs could be met at an 8ohm load.

Here is the spec from the Pioneer:

Now here is a current model Teac that demonstrates how these specs are now manipulated. Rather than 8 ohms, they show 6 ohms to boost the power rating. They also only show a 1khz signal instead of the entire frequency range. At 8 ohms across the entire range, either the power goes way down or the distortion goes way up, so this is how they hide that from the consumer.

Welcome to a world where electronics companies spend more on attorneys than engineers. (not really, but it seems like it)

 

[62caddy]

I would say that it is more of the manufacturers finding a way around it.

Here are the 1981 specs for my Pioneer SX-D7000. Back then, they only advertised the output at which all other advertised specs could be met at an 8ohm load. Here is the spec from the Pioneer:

Now here is a current model Teac that demonstrates how these specs are now manipulated. Rather than 8 ohms, they show 6 ohms to boost the power rating. They also only show a 1khz signal instead of the entire frequency range. At 8 ohms across the entire range, either the power goes way down or the distortion goes way up, so this is how they hide that from the consumer.

Welcome to a world where electronics companies spend more on attorneys than engineers. (not really, but it seems like it)

Thanks for the clarification.

 

[Pandovski]

Trolling doesn't help a discussion Pand.

Just warming up top enter the ring. :boxing:

 

[mhardy6647]

Specs are specs. Did you know that with the old spec, they have to warm the units first? During the warm up, they would push at the rated power for 1/2 hour and many units would shut down because of overheating? That would be ignored - this was discussed in another thread also.

SO, and your point is? The OP said the newer unit sounded better. Stop thinking this as old specs vs new specs. The issue is the unit's ages only and what maybe starting or already have started failing - like CAPS.

Actually the FTC preconditioning requirement was 30 minutes at 1/3 of rated power - but it is still a "sine wave" test and very stringent... much of the consumer hifi equipment was on the verge of immolation after 30 minutes of constant operation of 1/3 of its "RMS" (continuous) power rating.

The FTC spec only ever applied (i.e, as a mandated requirement for output power claims) to two-channel home hifi. Not car audio, nor portable audio, nor pro audio, nor any sort of multichannel audio. It is unclear to me (based on Googling) whether the 1974 specification as we all knew it is still in effect even for home stereo audio components. It may have been modified.

There are all sorts of issues as to how well (or even if) the continuous power output specification of a hifi component has any predictable bearing on the suitability of its performance in any given home hifi setting. In other words, when it's all said and done, it is a number that can be used to make a quantitative comparison between two components - but the qualitative comparison of the two won't necessarily be well predicted by the numbers.

As others have mentioned - old stuff that hasn't been refreshed isn't on a level playing field with a new component, full stop.

 

[onemug]

Remember....an amp gets its rating when it's tested into a "resistor". A speaker is NOT a resistor. Some speakers can beat the crap out puny little resistor.

 

[Pandovski]

Part 432 - POWER OUTPUT CLAIMS FOR AMPLIFIERS UTILIZED IN HOME
ENTERTAINMENT PRODUCTS
1. The authority citation for part 432 continues to read as follows:
Authority: 38 Stat. 717, as amended; (15 U.S.C. 41-58).
2. Section 432.2 is revised to read as follows:
§ 432.2 Required disclosures.
(a) Whenever any direct or indirect representation is made of the power output,
power band or power frequency response, or distortion characteristics of sound power
amplification equipment, the following disclosure shall be made clearly, conspicuously,
and more prominently than any other representations or disclosures permitted under this
part: the manufacturer’s rated minimum sine wave continuous average power output, in
watts, per channel (if the equipment is designed to amplify two or more channels
simultaneously) at an impedance of 8 ohms, or, if the amplifier is not designed for an 8-
ohm impedance, at the impedance for which the amplifier is primarily designed, measured
with all associated channels fully driven to rated per channel power. Provided, however,33
when measuring maximum per channel output of self-powered combination speaker
systems that employ two or more amplifiers dedicated to different portions of the audio
frequency spectrum, such as those incorporated into combination subwoofer-satellite
speaker systems, only those channels dedicated to the same audio frequency spectrum
should be considered associated channels that need be fully driven simultaneously to rated
per channel power.
(b) In addition, whenever any direct or indirect representation is made of the
power output, power band or power frequency response, or distortion characteristics of
sound power amplification equipment in any product brochure or manufacturer
specification sheet, the following disclosures also shall be made clearly, conspicuously, and
more prominently than any other representations or disclosures permitted under this part:
(1) The manufacturer’s rated power band or power frequency response, in Hertz
(Hz), for the rated power output required to be disclosed in paragraph (a) of this section;
and
(2) The manufacturer’s rated percentage of maximum total harmonic distortion at
any power level from 250 mW to the rated power output, and its corresponding rated
power band or power frequency response.
3. Section 432.3(c) is revised to read as follows:
§ 432.3 Standard test conditions.
* * * * *
(c) The amplifier shall be preconditioned by simultaneously operating all channels
at one-eighth of rated power output for one hour using a sinusoidal wave at a frequency of34
1,000 Hz; provided, however, that for amplifiers utilized as a component in a self-powered
subwoofer system, the sinusoidal wave used as a preconditioning signal may be any
frequency within the amplifier’s intended operating bandwidth that will allow the amplifier
to be driven to one-eighth of rated power for one hour;
* * * * *
By direction of the Commission.
Donald S. Clark
Secretary

From pages 32-34 on http://www.ftc.gov/os/2000/12/amplifierrulefrn.pdf

So basically stating 200WPC Musical Peak Power at 1kHz into 4 ohms is a disclosure. Does the normal everyday consumer understand it? I doubt it. They just use common everyday knowlede and see more Watts are displayed.

 

[cdfac]

another watts-vs-watts fact is that, because speakers are not resistors (as mentioned above), even two honestly and equally-rated amplifiers can have output that looks different into a real-world speaker load.

this is why Stereophile started testing amplifiers into their simulated speaker load. the results were generally visibly different, though i can't vouch for the audible difference in those cases. but in my OWN experience running a lot of more difficult speakers, this is why i've had smaller amps sound more powerful than bigger amps at the same general volume.

 

[mhardy6647]

...so, yes, some modifications from the 1974 mandate.

 

[Pandovski]

On page 16:

Velodyne stated that the power supply was the most costly and critical component determining an amplifier’s continuous power output capability, and that the primary quantitative measurement of interest to consumers is the amount of watts the power supply can deliver.27

If an amp has a fully regulated power supply it will deliver 30W in a way that feels more powerful, faster and more accurate than amplifier with same power but no regulation. A Naim amp may be "only" 30WPC but those watts are much more costly than your regular watts.

All animals are equal but some are more equal than others.

 

[kahlfin1k]

Power has NOTHING to do with how good an amp will sound. Almost all listening at reasonable volumes on reasonably efficient speakers is done at well under 5 watts. The only reason (and this is a legitimate reason) to have a lot of power is to drive certain speakers. A speaker that only needs 15 watts to drive to a normal listening level will sound no better on an amp that has 200 watts all else being equal. Amplifier sound has everything to do with circuit design and components and nothing to do with WPC ratings.

 

[89grand]

I'm not sure a regulated power supply really comes into play except for being able to compensate for sagging input power by providing more current if needed. If two amps can, and do, produce 30 watts per channel, are both on a stable power line, and one amp has a regulated power supply and the other does not, there should be no difference in perceived power output.

It does certainly cost more to produce a regulated power supply, and it may be beneficial in some cases, but I wouldn't say as fact that a regulated design performs better in every situation.