The SPU is the only Ortofon stereo cartridge that has survived since 1959 and from all over the world gained a reputation second to none for an outstanding analogue sound reproduction.
The original SPU model, engineered by Mr. Robert Gudmandsen in 1959, introduced low coil impedance concept. As a basis for reproducing superb high frequencies, this concept has been improved and refined in the decades since.
Robert Gudmandsen began working with Ortofon on December 6th, 1941 and remained in the company for more than 50 years.
He started his career as a radio engineer in a company where his father also worked, and he was later brought to Ortofon by Arnold Poulsen, one of the founders of Ortofon. Initially, Robert Gudmandsen worked on producing a dynamic amplifier for a local radio station. Later he was engaged in the development and production of condenser microphones. In the forties Mr. Gudmandsen had been deeply involved in the basic Ortofon Mono MC system. 10 years later Robert Gudmandsen, one of Ortofon’s then leading engineers, took a principal part in developing of the SPU cartridge.
In 1992 Ortofon wanted to celebrate Mr. Gudmandsen, because of his 50 years of work for the Ortofon. At that time he had already got the nickname Mr. SPU in Japan, because of his basic and innovative work on the mono moving coil and later stereo cartridges. Mr. Gudmandsen was also awarded by the Danish Queen Margrethe II, and Ortofon decided in his honor to launch the SPU Meister cartridge with Mr. Gudmandsen's signature printed in both A and G-models.
Then-CEO of Ortofon Eric Rohmann on the left awards the Danish Queen Margrethe II's merit medal to Robert Gudmandsen on the right →
In the years 1945-46 Ortofon started producing cutting heads for the mastering of new LP records. This led to the development and introduction of the first Moving Coil pick up in the world in 1948. That was Ortofon Mono Pick-Up type AB, A and C.
Mr. Gudmandsen had been deeply involved in the basic Ortofon Mono MC system. At that time Mr. Gudmandsen of course did not have the elaborate facilities that now make up the company’s development. Nevertheless his flair for a musical sound reproduction and the touch of a genius enabled him to create THE CARTRIDGE to survive all others.
The first SPU came to the market in 1959 (the term "SPU" stands for "stereo pick-up" as phono cartridges were called "pick-ups" in the 1950s and 1960s).
The original SPU was introduced in response to the demand for cartridges to reproduce the new stereo records. Based on Ortofon’s already 10 year old technology and experience in mono cartridges, the SPU immediately set the standard for professional and audiophile applications. Mr. Robert Gudmandsen took a principal part in developing this cartridge.
This first stereo cartridge actually consisted of two parallel-mounted cartridges. The armature was connected to a common cantilever via an extremely complicated universal joint with sapphire bearings. (Universal joint design is no longer used in the production of Moving Coil phono cartridges).
A key SPU feature is an integrated headshell, designed to mount directly into classic tonearms with detachable headshells - tonearms such as the SME 3009 and 3012, and other tonearms with similar "universal" tonearm mounts. Quite simply, there is no finer complement to a classic tonearm with a detachable headshell than an Ortofon SPU. The SPU also has a new elliptical needle, which gives a somewhat lower wear at approx. 4-g needle pressure.
According to Robert Gudmandsen, the SPU has its own distinctive sound because of the very unique structure of the cartridge, where the cantilever is secured in a 0.11 mm thin piano wire. After placing a tiny rubber ring, the wire is nickel-plated around the ring, which makes it 0.3 mm thick. This ensures a fixed pivot point at the thinnest point of the wire.
Back in 1958 the Ortofon SPU sounded like no other cartridge because it was way ahead of its competition. Today the SPU still has a sound that is definitely its own and it enjoys a remarkable following - in particular among audiophiles whose systems are comprised of vintage valve equipment and horn or reflex speakers.
In the early sixties Ortofon was the moving coil manufacturer with the SPU range comprising three models: E (elliptical stylus), G (standard SME-fit G-shell) and T (with or without step-up transformer). In the later sixties the popular SPU G-house model gradually evolved to become the popular SPU Classic, which was re-introduced in 1987 with some slight improvements.
The SPU Classic embodies the essence of the original Moving Coils and is known for its dynamic and powerful sound reproduction.
SPU of 1959 pointed the way for the next 50 years of high-end cartridge design: a generator comprising two low-impedance coils, wound with very fine copper wire and crossed in such a way that the two walls of an LP's stereo microgroove could generate two discrete signals with maximum separation. Today Ortofon has the world's largest program of pickups in all price ranges and all types, but despite the development of new pickups from Ortofon, a legion of music aficionados prefer the sound of the good old SPU.
While celebrating his 40th anniversary Robert Gudmandsen visited Japan and Hong Kong. The trip was unforgettable and mostly resembled a triumphal tour. It was on this trip that Robert Gudmandsen was nicknamed Mr. SPU.
Along with the production of MC cartridges, Ortofon also developed the Moving Magnet cartridges. These were initially somewhat clumsy and with a very low output. Robert Gudmandsen was involved in developing the Variable Magnetic Shunt principle that solved many of the reoccuring problems; among other things it obtained a high output and a very low moving mass. A contributing factor to the success of the VMS pickups was a specially developed rubber suspension, that together with the low mass secured a very large frequency range. The VMS pickups, although well received, were replaced with a new technology in the 80s, and an even higher output of the MM pickup was obtained.
For many years Robert Gudmandsen brought the pickups home with him to test them to the enjoyment of both neighbors as well as other local residents.
Robert Gudmandsen enjoyed his retirement in the small town of Præstø, located between Copenhagen and the Ortofon headquarters in Nakskov. Mr. Gudmandsen passed away 16th March 2012.