El Reg: "Can you explain the technicalities behind the sprung metal strip holding the felt pressure pad and the metal plate behind it in the cassette?"
Lou Ottens: "The pressure should be very light, because the forces inside the tape transport mechanism are kept as low as possible and any disturbance originating from a different pressure on the the tape can cause speed irregularities. The phosphor-bronze spring which carries the felt pad had been chosen to avoid eventual magnetism of a steel spring in the direct neighbourhood of the recording head. The mu-metal screen serves as a shield against interference that might be induced in the head during playback."
There's a lot more thought gone into this than just two spools
El Reg: "Did Philips have a frequency response in mind for the Compact Cassette or was it a case of experimentation to see what was the best you could get out of it?"
Lou Ottens: "At the time of the concept (somewhere around 1960 ) we were not thinking about hi-fi or something similar. A cheap, portable proposal which, hopefully, would find a willing market.
"As far as I remember, with this little machine, we were happy with 80Hz~5kHz [frequency response], which was in balance with the loudspeaker, the simple electronics and final stage and the existing tape performance. It would gradually improve, because the tape suppliers were in full swing."
El Reg: "Establishing bias and equalisation curves looks like it was a major R&D effort as these factors were to become standardised. Were other options explored, such as a new tape speed to deliver even better results?"
Lou Ottens: "As long as there was no technical revolution at stake, international standardisation was a holy cow with Philips, and rightly so. Tape speeds were standardised from 15 , 7.5 ips, 3 ¾ IPS , 1 7/8 IPS. No reason for us to choose something out of that range."
El Reg: "Had their been any significant technological advances that Philips was using that made the Compact Cassette recorder possible?"
Lou Ottens: "Yes. In the component division of Philips there was a considerable activity going for the miniaturisation of electronic components. The components, like electrolytic capacitors, ceramic capacitors, resistors, transistors (ICs were not yet a reality), switches, potentiometers and connectors were made fit for direct mounting on a printed circuit board. Their height was standardised to a maximum of 10mm and we anticipated using them in time for when the parts became available."
Fisher Compact Cassette recorder with Dolby B from July 1970
El Reg: "How did you feel about Dolby B being widely used on Musicassettes? It seems people didn’t remember to use Dolby B or even have it and so they were listening to bright, compressed audio which could be noisy too. Were you concerned or was using Dolby (at least, in theory) a welcome addition?"
Lou Ottens: "We didn’t like it at all. It complicated our products and it destroyed the international standard we had established with the competition. I was of the opinion that the rapid improvement of the tape performance by the international tape manufacturers would make the Dolby system obsolete, apart from the professional field, where the genius Dolby was normally active.
"I was afraid that it would cause a lot of confusion in the market. And I think I was right. But being right is not always good enough. Ray Dolby came to visit me and I gave my arguments, but he went on. Lesson: you cannot stop progress..."
El Reg: "Were you consulted on the development of the Digital Compact Cassette – DCC?"
Lou Ottens: "No, I was not consulted."
El Reg: "What are your views on the DCC format?"
Lou Ottens: "I am only slightly aware of the exact specification, so I will refrain from an opinion."
The Compact Cassette launch at IFA in August 1963
Source: Philips Company Archives
El Reg: "Regarding the introduction of the Compact Cassette and the widespread adoption that would follow, what was the biggest problem that was overcome and what was the biggest surprise?"
Lou Ottens: "The biggest problem was to realise the timely introduction for the Berlin exposition in August 1963. The biggest surprise was the world wide revolution it caused in the individual availability of music. But that surprise came into being only very gradually, which is not normal for a surprise."
El Reg: "If you could have changed something about the Compact Cassette before its final release, what would it have been?"
Lou Ottens: "Nothing."
El Reg: "Is there anything else you would like to say about this landmark project?"
Lou Ottens: "I have tried to give answers that make it clear that successful products are created by normal people who just follow their intuition, work hard, make mistakes and work together as a bunch of friends. A number of the key personnel that played an important role have passed away since those days. I remember them with respect and friendship." ®