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Inter.View with Vincenzo Fratello, SAP (Strumenti Acustici di Precisione, "Precision Acoustic Instruments") owner and chief designer

by Lucio Cadeddu

[Italian version]

LC >
Would you introduce Strumenti Acustici di Precisione to our readers? When was your idea born, and which were the guidelines?

VF >
Give voice to the best tube amps is SAP's mission, and it perfectly describes what was -at the same time- the evenience for our birth and our company's main (key) idea. When we begun our work, "far" back in the 1994, it already was an era of tube amplification revival, at least in the high end lands; yet there were very few loudspeakers good to "give voice" to the best tube amps, usually sporting very low output power.
The only adequate speakers were audio's golden years designs (Klipschorn, Altec la voce del teatro, the bigger classic Tannoys), that presented some drawbacks no longer acceptable by audiophiles' _meanwhile modified_ (I didn't say improved!) tastes.
Our speakers are born to fill this empty space, avoiding some of their ancestors' "sonic" limits, with an easier price and size.
Nowadays the situation is not that different; our competitors are still ... not many, while our products range is wider, extending either to the low level (smaller boxes and full-range speakers) and to the high level, where the peak is represented by our system "La Voce" (The Voice, Tr.), right in these latter days overcome by our newest "Gran Coro" (Great Chorus, Tr.).

Today, SAP is also marketing its first tube amp (an absolutely unconventional OTL design), its cables, either interconnects and speaker, and .... its turntables, with our refurbishment of the famous, yet sadly no longer produced, EMT 948. We're also working at a Home Theater System that -in our plans- will be available for the Top Audio '99 in Milan.

LC >
SAP's products seem to be oriented towards high sensivity and low-power tube stuff. Which are the substantial reasons to prefer this approach?

VF >
To give you a good answer, I need to make clear what our opinions and overall experience are.
"No valve, no music" is our company's bare opinion about amplification technology. The presence of tubes is a necessary, yet not sufficient, condition to get a correct music reproduction.
We are not khomeinist about the circuital design of an amplifier: there are superb examples of push-pull design, as well as (lots of) very bad examples of single-ended designs.
If I am to say it all, there are very few amplfiers that sound good, even though they use her majesty 300 B, or the Princess 2A3. And we like even fewer 211 or 845-based amplifiers, and usually they are extermely expensive, and badly "hand made".
Neither we are extremist about the "amount" of parallelled valves in the output stage, nor about the total stages number. We can (even!) think that a solid-state power section can work very well, at least up to a certain price level, and that an integrated amplifier can sound better than a couple of preamplifiers and their monoblocks amps.
Speaking about output power, we think that it -either with valve and quality- is extremely expensive, but we don't think that 1.5 Watts sound necessarily better than 50 Watts: of course, in that last case, it is fundamental that we get quality in the "first watt", the one mostly used with adequate loudspeaker systems.
If you ask me a "technical" explanation for our absolute preference for the vacuum tube as audio amplifing element, I honestly must answer: I DON'T KNOW.
My electronic engineer background, and its related professional deontology, don't allow me to climb on a glass wall to find a pseudo-scientific explanation, as well as many others do.
Of course, I gradually developed some ideas about it, but I still have no "proof" for them, so I keep them for myself.

So, let's figure that we can count on an output power rated between 10 and 20 watts, which - in a cost-oriented argument - already asks for a good amount of money to be spent with tube technology and appropriate quality.
A loudspeaker sporting a sensibility of 95 dB/ W/m produces a spl ranging from 105 to 108 dB. Put in a reasonably sized room (up to 35-40 square meters), with the companion stereo luodspeaker, taking into account walls reflections, it is clearly able to generate a sound level as high as anyone can ask for.
Moreover, almost all decent loudspeakers can easily manage such a power without incurring in dynamic compression.
Yet, all those arguments - although very significant - are not enough; the reason for which we prefer to use loudspeaker with sensivity higher than 95 db comes from another consideration.

Sound and music consist of air pressure variations: a system able to more naturally and easily follow those variations can surely best approximate the original event. Particularly if, then, this system can be "fed" by a valve technology amplifier (the only technology featuring adequate musical performance), instead of requiring 1KW of solid state amplification to move the air; it will be closer to music, indeed.

LC >
What are the main problems concerning the project and the realization of a wide band driver?

VF >
We all know, having experienced it at least once, the "too-short-blanket-problem". Designing a wide band driver is the same kind of problem..
Let's figure, to simplify, that its basket was already good designed. We have to work, balancing often opposite needs, on four variables: magnet, gap, voice coil, membrane and suspension.
To extend the response to the highest frequencies, we need to have light moving parts (membrane and voice coil) and to stiffen the suspension.
On the other hand, to reach a low frequency extended response, we have to lower the resonance frequency, with a bigger moving mass and a softer suspension.
Yet, we can reach high frequencies improvements, without a worse resonance frequency, by modifying the membrane's shape (leaving unmodified its mass), or by substituting the anti-dust cap with an adequately profiled ogive.
Or, we can improve low frequencies response extension by using a differently charachterized magnet, with no defeats in higher frequencies response.
Since - as for all drivers - we need to decide its required "attitude" at rising applied power, that is its linear escursion limits, and, once again, tweak the voice coil and the gap, the problem changes itself into the choice of the best balancing between sensibility, resonance frequency, and managed power.
Like for all transducers (devices that turn a certain kind of energy into another one), designing a driver, particularly a wide band one, is a delicate exercise of knowledge, experience, balance between physical phenomena seemingly in unsolvable contrast each other.

LC >
The revenge of valve technology is presently under everyone's sight: in the market, there are many new producers and products. What really new and original can be found in a tube design, when many commercial products are just little variations of 50's schemes? Are you expecting a reduction or a further expansion of this tube wave?

VF >
Apart from the basic technology involved, it is always possible to innovate. To answer to your specific question, today we have available and diffused calculation and measurement instrumentation that is very different from that of the 30's (or the 50's), and great progress was made in the field of passive components (I say this although our love for oil and paper capacitors, that we use in almost all our speaker's cross-over networks).
The SAP Anniversary integrated amplifier is - for what we know - world's only OTL, single-ended, zero feedback amplifier. For as little as this can be, we certainly designed an innovative product that - moreover - is particularly innovative even under its sonic profile.
Anyway, I think that the tube wave in the next years is going neither to grow, nor to re-dimension itself: I foresee that the status quo will be kept as is now.
Nonetheless, we are going to surely see the market positions move toward companies and poducts that really have something to say about quality audio stuff.

I foresee (and wish) the collapse of unprepared experts, the only depositors of the "Truth" and the "Right", those who roll output transformers only during equinoxial full moon nights, using platinum strings (left) hand-wired by their unmarried sister....! :-)

LC >
Speaking about high sensivity speakers, ideal partners for low-powered valve amplifiers, it is usually needed some big and complex horn loading. This, somehow, limits the domestic acceptability for such products. We know that you are working at a compact horn speaker. What compromises and what advantages did this approach have?

VF >
In pursuing physics laws, we had to accept less ability to produce energy at low frequencies, compared to a 15" woofer. I think this is the only accepted compromise in the Anniversary's design.
The advantages are the usual ones in high class horn loaded speakers: sensitivity, easy driveability, very natural emission, dynamics, microcontrast, "horn"-like, that is, realistic low frequencies.
By realistic low frequencies I mean ..... exactly the opposite of those coming from 95% of home theater commercial sub woofers! Let me clarify that the Anniversary is full horn loaded; the tweeter, too, a component that we completely developed by ourselves, is loaded by a little wooden tractrix horn. Low frequencies horn sports a teoric design cut-off at 40 Hz, and is almost 2 meters long.

LC >
As I often, sadly, say, "nemo propheta in patria", that, translated into HiFi language, means that a producer (or a magazine, like in our case), to earn domestic respect, must first get appreciation abroad.
From this point of view, the internet gives chances simply unbelievable just a few years ago, and TNT-audio is its most evident demonstration.
What chances there are, for an Italian brand, to be famous abroad, what are the difficulties and the strategies?

VF >
Thanks to the work of many companies, abroad Italy now entered the exclusive club of High End production countries. Quality in sound, project, and - not least - finishing and design is now taken for granted.

The ability to estabilish abroad are significant for any company, but we need to be strongly competitive as "company system", it is not only a matter of product. This is not easy to reach in a reduced-number sectorial market, although, I must say, a lot of Italian companies are already worldwide competitive in terms of products, and some of them even as "company system".
The difficulties stay in the high investments needed to promote your products, and in the extreme lenght of those investments' returning time. At least we need to organize in terms of mid-period, not being hurried to recover our investments (let's say a cash-flow at break even) before the third and fifth year of abroad operation. Other jobs are, under this point of view, much more attractive!

SAP strategy is pretty simple: a wide range of loudspeakers, but always well "in line" with company's philosophy, a wise addiction of other components, such as amplification and cables, the development of a home theater system (amplification and loudpeakers).
This last point has now become substantial, because a lot of distributors, to grant your product distribution, want you to have some home theater components available in your range. Abroad, distributors tend to have a reduced number of brands, that can be referred to a definite company strategy; this leads to a strong promotion and a bigger deal amount for each brand.
The exact opposite of some big italian distributors....the so-called onniorous, dealing with dozens of brands, wihout a strategy, and with very little deal amount for each brand.... just to see what is cool!
Geographically speaking, our company's interests are moving from American and Asian markets to the European ones, particularly to our new domestic market: european union.

LC >
What are your "dreams in the drawer" ?

VF >
Companies don't have dreams, but programs, development plan and strategies to make dreams come true.
Yet, we too have a dream: that our market - after this long illness period - comes to a healing by a fan generation turnover and the definitive - uncomplained - disappearing of all those who contributed to reduce it in its present conditions after having raised from it huge profits for years.

S.A.P. has its seat in Italy, Salerno, Largo Plebiscito, 6, ZIP CODE 84125. Telephone and fax: +39 089 250979. E-Mail: sapmkt@tin.it and is - by tradition and constitution - really happy to answer to every "fan" question.

Courtesy of Vincenzo Fratello for TNT-Audio.

Copyright © 1999 Lucio Cadeddu

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