Dear Editor (Apr. 1975)

FTC Power: Round II

Dear Sir:

In response to Mr. Robert Tucker's article, "An Alternative View" (February), and the continued flagrant violation by several manufacturers and publishers in permitting illegal advertisements to appear at this late date: We believe the consumer of audio amplifiers does not buy them by the watt as he would gasoline by the gallon. Just as it takes 40 square yards of carpeting to cover 40 square yards of floor, it takes a minimum number of watts to drive a given speaker system to a given sound pressure level in a particular room. Beyond this, the choice is usually one of quality. Forty square yards of $3.50-per-square-yard synthetic carpeting will cover the floor as well as 40 square yards of $25.00-per-square-yard of the finest all-wool broadloom. But, there will be a difference in the feel, the wear, and the longevity.

As Mr. Tucker stated, BGW Systems does indeed make "tanks." But our tanks come in many sizes, all rugged and all designed to give the con sumer a conservatively designed product for his dollar. So, although the FTC regulation may force the con sumer to pay more dollars per "brown-goods" watt, our real watts (and prices considering inflation) remain almost the same.

The sonic benefits are far from "negligible." As we stated in our article, conservative design has made it possible to build an amplifier without current limiting circuits and their inherent problems at high levels. A-B comparisons will prove this to be a far from "negligible" gain.

Mr. Tucker claims that the rule will result in reduced product information. We feel that it will result in reduced audio-fiction but much more real product information. Since not only manufacturers but dealers and publishers as well are covered by the enforcement provisions of the rule, the information that the consumer will receive will be based on minimum performance under rigid test conditions. True, there may be a good many shorter spec sheets, but what they say will refer to the actual product and not to a pipe dream of a clever copy writer.

We at BGW Systems are appalled at the apparent disregard of the law by several other manufacturers by running advertisements which do not comply. Furthermore, we feel it is the publisher's responsibility to see that his magazine prints only that material which is written in accordance with the law.

Brian Gary Wachner; BGW Systems, Beverly Hills, Calif.

Editor's Note:

Mr. Wachner's letter would lead one to believe that a magazine, such as Audio, has a duty placed on it by the FTC's power-output regulation to police advertisements for amplifiers and receivers.

This is not so. First, the courts have often held that a publisher may not censor ads unless he can show outright slander or pornography (and even this last is again open to question). Second, the FTC would bring all advertising of these products to a grinding halt were it to require the publisher to test the products; obviously an impossibly expensive task and one which many publishers cannot perform even on a single unit. Third, it is similarly impractical for the FTC to require that a publisher obtain certification of compliance with the rule from an advertiser since by advertising the product the maker is prima-facie saying that his product DOES meet the standards set up by the rule. Fourth, the rule, as promulgated, makes no mention of publisher responsibility. To extend that responsibility to the publisher would be to lose sight of whose product is being advertised by making the publisher a "policeman" agent of the FTC. Audio has been in consumer fights before, and we applaud the basic intent of this rule. However, we cannot act as the FTC's unpaid agent.

It would be cheaper to simply stop accepting ads which made power output claims.

We therefore reject any interpretation which makes a publisher responsible for the power-output claims contained in advertisements.

Mr. Tucker Replies

Dear Sir:

Lest the first paragraph of Mr. Wachner's letter be misinterpreted, any reference to power output in Dynaco advertisements published since the November FTC Rule date conforms to the strictest interpretation of the Rule. While we strongly contest certain aspects of the Rule, we believe in full compliance until it is altered. We deplore attempts to subvert it, especially those specifications written in apparently conforming format, which neglect to mention that they ignore the stringent preconditioning requirements.

While the FTC has indicated that it will not sue for misleading advertising under the preconditioning paragraphs of the Rule until the Dynaco petition is resolved, such advertising tactics adversely reflect on our industry's credibility, and further confuse the customer. And, since neither the magazines nor the dealers are in any position to police power claims, a massive investigation and enforcement campaign will have to be speedily implemented by the FTC if those with honest ratings are not to suffer disproportionately. In the intervening months or years, more confusion could result from misinformation under the guise of compliance than from the nonsensical power rating of the past.

While we wish it were not so, too many amplifiers are indeed bought "by the watt." Were that not true, the Rule would not have been so sorely needed. BGW may find it less of a problem in their marketplace, but with several hundred thousand Dynaco amplifiers behind us, we are quite aware of typical buyer priorities.

We doubt that the Rule will have much effect on mass merchandise "brown goods" audio, other than to suppress any references to power ratings. We'd prefer, in fact, that the Rule require some rating, preferably with a minimum bandwidth requirement, as did the original New York City power Rule.

There is no relationship between the design requirements to conform to the Rule, and the supposed sonic benefit Mr. Wachner claims from leaving out current limiting circuits in his models. Current limiting could be left out of a cheap design too (few of these now include it), or another engineer might still choose to add it to the BGW 750A "tank" out of zealous conservatism. Given an acceptable amplifier by previous "rms" or continuous average power measurements, any change to the Rule will not improve its sonic quality one iota.

Fans, in fact, degrade achievable signal-to-noise ratios in the listening area.

We concur totally in supporting the Rule's provisions which help to remove information of dubious validity from the spec sheet, and secure it from the copywriter's influence. But we believe that realistic power specifications at all useful impedances are helpful to the purchaser. The Rule requires complete specifications for all impedances "for which the manufacturer designs the equipment to be used." Currently, manufacturers can easily circumvent their problem of ridiculously low 4 ohm ratings with preconditioning by not "designing" the amplifier for 4 ohm use. There is no assurance that the FTC will tolerate that loophole, especially with amplifiers which have previously been rated at 4 ohms, or those which include "A+B" parallel speaker switching, or those which make reference to such use. Or do we assume that only 16 ohm speakers may be used for such parallel connections? This is not to say that all amplifiers must be rated at all 3 common impedances, but rather that if the manufacturer so chooses, or the buyer requires that information, that the figures thus given bear some sensible relation to real capability. Only then can the buyer weigh the advantages (higher available output) or disadvantages (destructive capability) properly.

I note Mr. Wachner said that fan cooled amplifiers and those "designed for 2 ohm use" are those least affected by the Rule in retaining existing power ratings (at least down to 8 ohms or possibly 4 ohms). But, by definition, such amplifiers must now carry 2 ohm power ratings as well! Lest it be thought we are jousting at windmills, one example should clarify the fallacy in the Rule's requirements, though more extreme examples can be found among popular amplifiers. The Dynaco Stereo 400 has more heat sink per output transistor than any other amplifier we know of--1.2 pounds of aluminum, and 130 square inches of radiating area per device. We could design it to include a noisy fan, but instead we've designed it for better performance without a fan, and with tighter thermal protection. Reviewers have not found any need for a fan on the Stereo 400 (even though space is provided on the chassis) because thermal tripping is almost non-existent on the thousands in use.

The Stereo 400 has always been rated at 200 watts "rms" per channel into 8 ohms, and 300 watts "rms" per channel into 4 ohms, which reviews have fully supported. Under the Rule, the rating is now 200 watts per channel, both channels fully driven into 8 ohms, across the entire audio band of 20 Hz to 20,000 Hz, with total harmonic distortion always below 0.25%. While it can deliver a full 300 watts for some 10 minutes without a fan (a far cry from a "music" or "peak" rating), the even higher heat output at 1/3 power required for pre-conditioned necessitates a sharp reduction in rated 4 ohm power, since thermal cycling is not permitted. To keep the transistor case temperature below 85°C for an hour's operation at 1/3 power, the amplifier would have to be rated at less than 30 watts into 4 ohms, but Dynaco believes that the customer must be warned that this amplifier can deliver 300 continuous watts into his speaker.

In effect, the law requires that misleading information be supplied, unless a 4 ohm rating is not given. If it is not given, it implies that the amplifier is not designed for operation into 4 ohm loads. Further, monophonic bridge operation would yield a rating of less than 60 watts into 8 ohms by the Rule (far less than in stereo operation) when in fact the amplifier can deliver--even without a fan--more than 10 times that for long periods of time, with potentially destructive capability which the unknowledgeable consumer should be informed of.

A conventional "whisper" fan mounting gains only incrementally in this power rating, but because we are talking about relatively small thermal reductions to get inside the thermal cutout limits (they are mounted on the transistor cases), simply changing to a noisier, high speed fan blowing down into the same heat sink enables a fully comparable 300 watt rating under the Rule, with the same thermal protection.

There are other ways to this end, of course. One way is to add output devices to increase the thermal inter face area. This would enable backing off on V-I limiting too, as Mr. Wachner prefers, but at an unjustifiable cost penalty for the vast majority of users. Or, we could save money by eliminating the protection of thermal sensors entirely. Once the sensors are moved farther from the output device, and especially when their trip temperature is raised, their real effectiveness is largely nullified. None of these 3 courses benefits the con sumer, or affects the reproduction quality, and two add considerable cost. Product safety even becomes a factor in some other designs for the Rule's test pushes the heat sink temperature above 100°C in some units. If the heat sink gets that hot, think what the chip temperature is, and how far beyond its safe operating area! As to consumer confusion, let's take the case of two versions of a current amplifier which sports an impressive heat sink, but which for all its output devices, has limitations in thermal transfer to the sink. One version has been previously rated for con sumer use as upwards of 200 watts per channel into 8 ohms. Another commercial version (hence not liable under the Rule) is typically rated on its much higher 4 ohm output (though the impedance is not always identified), and it is regularly advertised in the popular music magazines. If the maker chooses not to rate the consumer version's 4 ohm power output under the Rule, what is to prevent a dealer from making the sale by pointing out the obvious similarity to the commercial version, and claiming the higher (4 ohm) output? Is it a molehill, or a mountain? One manufacturer has said he had understood that so long as at least one power rating could be affirmed under the Rule (as at 16 ohms, where the heat output is less) others on the same amplifier would not be questioned, so long as they were "reasonable" in terms of past rating practices! Thus those who believe in strict interpretation would be severely penalized for their honesty.

Another manufacturer has indicated they are "sure the FTC are reasonable people, and won't interpret the Rule too stringently, because otherwise, massive redesign would be necessary." It is unreasonable to expect the FTC to second-guess their Rule, and interpret it in a light favorable to part of the industry. Literal interpretation must be assumed, and if we do not effect change now, we must suffer the consequences, and the consumer will be footing the bill, with no apparent benefit.

(Continued on page 77—content to be added soon!)

( Audio magazine, Apr. 1975)

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