The history of the Acoustical Manufacturing Company, Huntingdon, England is a long and interesting one. I intend to cover it very superficially here, but yet provide a reasonable framework in which we can place the Quad ESL, perhaps their best known product. For a more complete look at the Acoustical Manufacturing Company I would recommend a read of Ken Kessler’s excellent book - Quad - The Closest Approach - published by IAG in 2003.

Peter James Walker was born in 1916 and educated at Oundle, England. He worked for EMI and GEC, and founded the Acoustical Manufacturing Company in 1936. In his own words:

"No, I didn't start with manufacturing, that was after. I worked for a firm selling amplifiers. I sold an amplifier one day for thirty pounds, and I thought, 'Well, I dunno, the parts here can only cost five pounds, I could buy these parts, put it together one day and sell it the next day and make twenty-five pounds, couldn't I?' Very much better than the less than two pounds a week I was getting at the time. So I handed in my notice and started. That was doing public address though. I was installing a couple of loudspeakers and a microphone in a dance hall or cinema, which was never very lucrative. We struggled with that for a number of years. The difficulty there was that you'd got to produce the maximum number of Watts for the minimum number of pounds, and if people wanted a really good job they'd go for the big names like EMI or Standard Telephone. Everything had to be tendered (bid for). People would either take the cheapest, and the cheapest bloke always lost money anyway, or they took the most well-known, which we weren't. We were in the middle. We started in high fidelity before the war. But Paul Voigt, when he was in England, was making a much better loudspeaker than anyone else, but two a week was his maximum sale. It cost thirty-five pounds, which I suppose in present day terms would be about six hundred pounds. It was very expensive. But he couldn't do it on his own because there was no high fidelity market. You've go to have a lot of people making things, to get the advantage of the group advertising. In 1937 or '38 I made a high fidelity amplifier, push-pull, 25 Watt, triode, direct-coupled, with feedback. Oh yes, very good. But you couldn't really sell these things, partly because the records in those days were all 78 with a lot of scratch. People said, 'What's all that frying bacon noise?' The BBC was very good. For the speakers, we had the voigt, there was also an infinite baffle in those days, in fact, before the war, we had an acoustic suspension speaker in the Audiom 8. It had a fundamental resonance in free air of 16Hz., and was stuck in a three cubic foot box, which forced it to 50 Hz. It was an acoustic suspension speaker, and that was around 1937 or so. But again, there wasn't a big sale for this because there wasn't a high fidelity market."

I went into hi-fi as a sideline 'til the public learned to like it. You made a set for yourself; you sold these to a few engineers, about five or six a week, that sort of thing. Then of course hi-fi came in, mainly with the LP record, and since we were already in the business one could get pushed up with it - doing the right thing by luck at the right moment. This is really what most of these things are about, aren't they?

So, there you have the genesis of Quad, in the typically modest view of it's founder. Of course, what Peter Walker fails to mention in his modesty is, that if the company you are running produces rubbish, or unreliable equipment, then you probably don't stay in the business very long. What a refreshing alternative to the self-possessed paranoia one observes in the world of audio today, with it's claims to constant improvement (a myth) and having reached audio nirvana (they must have missed it on the way to the sales meeting). On that very subject - audio 'breakthroughs' - here is Peter Walker's view:

"Well, there aren't that many breakthroughs. There are a few, yes. The transistor was a breakthrough, stereo records were a breakthrough, yes, and the invention of the tape recorder was a breakthrough. Oh yes, there've been some minor ones as well, but they don't come out every six months. But if you take the sound, which was produced 25 years ago, it isn't that much worse than what we produce now. We recently had a party of Japanese coming in and put on a demonstration for them of equipment that was over 20 years old. The whole lot of it, including the records, was surprisingly good. It wasn't stereo, of course. The only thing wrong with it was that it was mono. It was extremely good otherwise. Perhaps the signal-to-noise was not quite as good as one can do these days, but the realism and naturalness were all there. We used a Ferranti pickup. An excellent device. It was made between '50 and '55, I'm not quite sure of the exact date - so we played that, on a good mono record, through our prototype electrostatic speaker. But I believe you've been able to make amplifiers as good as you want, certainly for 30 years. [This extract is from a 1978 interview]

After the Second World War, Quad had the Quad corner ribbon as its premier loudspeaker. This consisted of some folded electrostatic membranes and moving-coil drivers that (as the name suggests) had to be placed in a corner to get the bass end to work properly. In Peter Walker's (1994) own words, again:

"The ribbon was a hybrid; the ribbon itself was very good from 2000 cycles upwards and the bass unit was very good up to 500 cycles. Not very good in the middle, which I can admit now, but there you are. During the ribbon speaker's life we sold less than a thousand units. It wasn't pairs, it was all mono; there wasn't any stereo then. And they were 95 pounds a time, which in present-day money is quite a lot."

So, when was the "moment", as they say when Peter Walker first began to think about the Quad Electrostatic. He says:

"I've always thought, right from, oh, 1945 I suppose or thereabouts that an electrostatic would be a nice way of doing it. But its in the back of your mind, how can you do it?"

How, indeed? Well, the technical history is another, rather drier matter, and if you like to wallow in patent trails, then the patent history of the Quad is for you (see ESL 57 and ESL63 Patents). In 1951, the Quad amplifier was introduced, as a successor to the QAP/12. The latter, although designed for public address, originally was finding some favour with the burgeoning hi-fi community. Music listeners soon realised that it was much easier to say and remember QUAD than "Acoustical Manufacturing Company". In 1954, Professor F.V. Hunt wrote a mathematical treatise on electroacoustics. His book brought together many ideas that had been around the world of sound reproduction for about 30 years, but, most importantly, Hunt provided the mathematical justification for the superiority of the electrostatic speaker. Peter Walker surely read this work, and by 1955, in the venerable journal "Wireless World" a series of three articles entitled "Wide Range Electrostatic Loudspeakers" appeared (May, June and August). A few months later the Quad Electrostatic Speaker was ready for production - the patents were filed on July 15, 1955 ( U.S. 3,008,013 ),  September 12, 1957(U.S. 3,008,014) and granted July 8, 1959 (G.B. 815,378). Two of these dates are often thrown about in conversation as the model number (e.g. Quad 55, Quad 57). There was no such designation and the designers called it the "Quad Electrostatic Loudspeaker" (look at the back of the speaker). The reputation of Quad in the post war era was founded in large part on this speaker and the Quad II mono amplifier. These two products established the fame and fortune of Quad and had a deep and lasting affect on the audio industry, setting a standard that many today would do well to emulate, if they could. One rarely met an audio engineer who had not used the Quad ESL as a reference standard. The rigorous scientific principles and analysis behind these early Quad products along with a rejection of commonplace solutions led to significant improvements in the reproduction of sound.

Although Quad, under Peter Walker's leadership went on to produce the ESL '63, which is discussed in some detail on this site, it is these early products which seem, to the annoyance of many, to go on forever. It is not a quirk of fate. It is not serendipity. It is not even fashion. It is the realisation that truth and quality endures.