History of the Schaub-Lorenz Music Center
Herbert Hamann, an ex-Graetz-SEL
employee who worked in Product Preparation with Wolfgang Gerwien, recalls fragments of the
birth, rise and demise of the Schaub-Lorenz Music Center, and reveals some of the problems faced
by the engineers and others involved in the making of the BBG tape
This short account of the history of the BBG is based on Konzept für Thema BBG, a talk
given in German at the GFGF radio club's AGM in Erfurt, Germany, on 17 May 2008, by Herbert
The transcript of this talk was gifted
to the author of this website at the end of the proceedings, which included a display of two
well-known music centers (5001 and 6000 models), and a very unusual music center that was specially
adapted with a stereoscopic slide-viewer (see Unusual uses).
In 1959, Graetz KG
 acquired Sander & Janzen (aka Saja), a company with factories in
Berlin and Duderstadt which made tape recorders, dictating machines and drive motors for
turntables. In 1960, following the acquisition, Graetz decided to transfer Saja's tape-recorder
development and production teams to their factory in Altena, Westphalia.
The Graetz factory, Altena, Westphalia,
company bulletin Graetz Nachrichten
Much of the material
that the Saja personnel took with them to Altena from Berlin and Duderstadt turned out to be
unusable. This was because Saja had failed to make proper technical or
production drawings beforehand.
Consequently, in order to enable further tape-recorder production, new drawings had to be made
again from scratch, in Altena.
Plagued by production problems
From the start, Graetz was plagued by Saja production
problems which took an enormous amount of time to sort out. One ex-Saja employee, the former
boss at Saja's plant in Duderstadt, who apparently knew everything about the tape-recording
machines, and who could have helped solve the production problems, was unfortunately not
available to them.
The Saja personnel who transferred to Graetz, Altena
struggled to sort out the chaos themselves, but never did. One day, production came to a halt,
Standard Elektrik Lorenz
later, in 1961, Graetz KG was bought by Standard Elektrik Lorenz AG (SEL), and the BBG unit
known as 'Division VI' became part of 'SEL's 'consumer electronics division known as
Schaub-Lorenz. For commercial reasons, the BBG became known as the 'Schaub-Lorenz Music Center'.
TEAM & PROJECT
Engineers flee to West
Meanwhile, in 1960,
four engineers working in Eastern Germany, namely, Friedrich Knochenhauer, Günter Löffler, Kurt
Senglaub and Hans-Georg Fuchs, quit their jobs in East Germany, crossed over to West Berlin with
their families, and ended up in a refugee camp seeking asylum from the Communist
Engineers with tape-recorder
engineers had all previously worked together in Eastern Germany for Funkwerk, a company
making tape recorders in the Köpenick district of East Berlin. Funkwerk was a subsidiary of
the measuring-instrument company Messgerätewerk Zwönitz, headquartered in Zwönitz, a town
nestled in the Erz Mountains south of Chemnitz. These engineers, together with their
families, settled in Altena, Westphalia, where they began working for Graetz KG as design and
development engineers, assigned to the music-center (BBG) project.
Music Center (BBG) project begins
In that same year, 1960, the main design and development of
the Schaub-Lorenz Music Center took place at Graetz in Altena, a project that became known
internally as the 'Breitbandgerät' . The four new engineers from Eastern
Germany, together with Siegfried Apitz [3a], the youngest member of the BBG team, plus the Saja
personnel, had the necessary tape-recording expertise to initiate Graetz's new tape-recorder
of the project
According to two members of the Product Preparation
department, Herbert Hamann and Wolfgang Gerwien, whose job it was to ensure that production-line
personnel knew how to assemble the machine, it was "not the aim of the BBG team to make a
professional machine to the highest standards".
One of the engineers, Friedrich
Knochenhauer, was appointed departmental manager to head up the BBG's design and
development team. He is described as "an exemplary individual", and was known to his colleagues
Hans-Georg Fuchs was given the
responsibility for the mechanical construction of the BBG (music center). Unfortunately, he died
in a car accident in 1963/64 during the developmental phase, and would never see the final
production version of the music center that he helped to develop.
MODELS & PATENTS
The team of
design and development engineers at Graetz/SEL devised four versions of their music center, but
only three models ever made it to production. These were:
1. The 5001 table model with 126
2. The 5005 upright model with a
simple built-in record player, and a mixer unit (5012) as an accessory.
3. A central chassis, type 6000,
complete with a 110v power-supply unit, a stereo version with 81 tracks, for the US export
market. This model was called the "STEREO tape recorder 6000" and was supplied with a manual for
connecting the chassis to a valve amplifier/vacuum-tube amplifier, and indicated that a 110v to
220v transformer would be required for use in Europe, and that further accessories were
A special fourth version
was conceived by the team for use by the Police for recording day-to-day work situations and
police proceedings. Of prime importance was that this particular tape recorder would have needed
a significantly greater recording capacity. This version was never made, and was just a pipe
plethora of patents
the midst of all the technical problems, Friedrich Knochenhauer managed to dictate a plethora of
patents to his secretary, Mrs Rapp, after hours , in the administrative wing
of the Development block.
Complex manufacturing process
Reminiscent of the troubles encountered earlier with the
transition of the Saga tape-recorder production to Graetz, Altena, the production of the BBG
also suffered major problems arising from the coordination of all the various manufacturing
In addition, there was very little tolerance in the mechanical and electrical components, which
only facilitated the occurrence of manufacturing faults . Consequently, many
components had to modified.
more a 'pilot' series'
Unlike the mass production of television and radio sets, the
design and manufacture of the BBG was more like a 'pilot series'. The BBG was so complex that it
would have been impossible to make thousands of identical copies. The team discovered that it
was not possible to produce a reliable device.
problems were with the reed relays and the wide
tape. As regards the tape, the BBG team were pioneering a completely unique, high-spec
material for use in tape recorders; the tape had to be very robust and yet very elastic.
Moreover, the tape they needed had to be 100mm wide and 150 metres long. A specification
requiring such a wide tape had never been produced before anywhere. These tape requirements
created a massive headache for the BBG team.
Choosing the material
for the wide tape
first the team experimented with tapes made from polyvinylchloride (PVC), but they did not work
because the tape transport from one spool to the other was insufficiently smooth. The team then
tried using a polyester tape. This proved a time-consuming and very costly
Incidentally, the propulsion
magnets (Ger: Zugmagnete) were also a bit of a problem. Their function is to
propel small levers forward inside a solenoid, to actuate the tape drum's brake, for example.
These magnets were known to make a scratching sound that was far from stimulating, especially
when you were trying to enjoy an evening of stimulating music.
The BBG's tape-recorder unit was assembled in SEL's factory
in Kaufbeuren, 91 kms south west of Munich, and in Rastatt . The machines
that were used to make the metal components for the BBG were made by Mitsubishi. All the rest of
the music center was made and assembled in Altena, and later at the FS factory in Bochum, 22 km
west of Dortmund.
PLUG PULLED ON PRODUCTION
After just two years, production of the BBG was terminated,
due in part to the introduction of the compact cassette (compact audio
cassette tape) by the Philips company in 1963, who offered a simpler and cheaper method of
recording on two pairs of stereo tracks.
Unsold stock of music centers
SEL sold off the remaining factory stock of finished music
centers cheaply, but this was not quite the end of the music-center story
In Germany, an electroacoustics
company in the Ruhr region purchased a batch of these left-over music centers, as did some
department stores, and used them for years to provide background music in public places
At the time, they were seen as a good alternative to renting music products such as Muzak, 3M or
Reditune, from the established background-music suppliers. By the time their recordings were made
available to customers, music-center owners had already recorded and were already playing the
latest pop-music numbers to their own customers.
became of the team?
1968, Standard Elektrik Lorenz AG began transferring their Production and Preparation department
and their Design and Development department from Altena to Pforzheim , where
their sales division had already been for some time [ed. ±
1965]. The remaining
members of the music-center's development team left SEL to take up new positions in various
He moved to a company in Munich called Grünwald, a firm that had made the drive motors for
the BBG. In 1973/74, Friedrich Knochenhauer suffered two successive heart attacks while driving
to work in his car, and tragically died in the car in the presence of his two daughters, aged
He worked for a time
with a company making radios called Labor, but later became a teacher in a
school in Gummersbach.
He went to
Telefunken in Ulm.
Wolfgang Gerwien and
They did not
want to move with the Product and Preparation department from Altena to Pforzheim and so decided
to go their own separate ways, although only geographically.
Wolfgang Gerwien went to Munich
to MBB, while Herbert Hamann went to work for a small technical office specialising in
electroacoustics, which was active in department stores.
End of document
Translated from the German with the help of Hans
van Straalen and adapted by the website's author. A copy of Herbert Hamann's
original German document can be found in the 'Archive' section.
further details on the history of the Graetz company, see the Graetz company history.
3. Patents: The industriousness and diligence of Friedrich Knochenhauer and
Mrs Rapp are reflected in the tables in the three Main Patents (see chapter on Patents), which
summarise the key components of the music center invention that were protected by patents he took
2. Breitband: A term Breitband
has caused confusion in the past when translated into English. The tape should not be translated as
'broadband' in English as that is a telecommunications term that refers to signal bandwidth,
something completely different from the designation 'wide tape' (preferred), or 'wide band' (see
was almost certainly due to inadequate quality control procedures and inadequate feedback to the
assembly line. This is described in 'Top 4 Faults, No. 1'.
sites: Rastatt was not mentioned as one of the manufacturing sites
in Herbert Hamann's Erfurt document.
6. Fate of other Music Center
stock:See (i) In
search of new business, and(ii) The 6000
7. Copyright: The department stores may have technically been in breach of
copyright legislation, which makes it illegal to play recorded music in public or in a public
place without paying royalties to the recording companies concerned. The same applies to those
hotels and pubs that used them. Whether they did or not, is purely academic
8. Move to
reliable source recently communicated the date to the author as being 1967.
9. Dates: The original date of Friedrich Knochenhauer's death is shown
in the Erfurt document as 1963/64. This is not. This would have meant that FK never saw the
launch of the BBG in 1965, and could never have left SEL for a company in Munich after
production of the BBG was terminated. After I had pointed out this discrepancy to Herbert
Hamann, he manually altered the date of the car accident in his document from 1963/64 to
1973/74. In fact, Kurt Senglaub has recently confirmed the exact date with me, but his final age
is still unknown.
10. The inventors:
(a) I recently discovered that Kurt Senglaub
was deliberately excluded from being mentioned in the patents as one of the co-inventors. For
further details, see my interview with Kurt Senglaub.
(b) Another co-inventor of the
BBG, again not mentioned in the 'Erfurt document', was Alexander Boom (see 'Main Patent No.
(c) Siegfried Apitz is not mentioned as one of the team of
engineers or as a co-inventor of the BBG in Herbert Hamann's Erfurt document. His name
emerged as one of the co-inventors during my research into the patents
later. See my interview with Siegfried
Photo: Herbert Hamann
giving a talk on the Schaub-Lorenz Music Center
to an audience of ± 92 GFGF members
in the Kaisersaal, Erfurt, Germany, 2008.