Was für ein System für diesen B&O Arm?

[kawabundisch]

Hallo ich suche ein System für den abgebildeten B&O Arm.Wer hat da eine Idee was ich brauche,oder wer hat da etwas für mich.
Gruß Bernd

[be.audiophil]

Moin,

der Tonarm heißt imho B&O ST/A ... und meines Wissens nach hatte Brent mal einen ... evtl. kann er Dir näheres über dessen effektive Masse sagen?

Ansonsten hätte ich für Dich diese Informationen zum Arm ...

Manfactured: 1958 - 1976
Designer: Erik Rørbæk Madsen & Acton Bjør
Colours:

Bang & Olufsen ST pickup arms were available in four different types: ST/M, ST/L, ST/A and the ST/P (professional studio model).

These arms were statically balanced by means of a specially engineered counterbalance so that they were in a state of neutral equilibrium if ever the spring under the arm was removed. Consequently, when the spring was put on it, this was the only factor determining the stylus pressure, which was always at right angles to the gramophone record regardless of the placement of the gramophone motor or of vibrations in the motor. B&O pickup arms were so perfectly balanced in fact, that you could play a record with the player standing on its edge.

Bang & Olufsen pickup arms had built-in compensation for the ingoing force or "skating effect" arising on account of the interaction between the offset angle and the friction between stylus and gramophone record. With B&O pickup arms, the stylus would always exert equal pressure on both groove walls which was of great importance when playing stereo records, where each groove wall contained a separate signal. If a pickup arm that has not been compensated in this manner was permitted to run on a smooth disc with no grooves in it, the arm quickly pulled towards the centre. This never happened with Bang & Olufsen pickup arms (if correctly balanced) in that they always kept the same distance from the centre of the record.

The Integrated tone arm ST/P won the iF Design Award in 1963.
Type ST/L-15 Pickup arm

Is statically balanced by a specially designed counterweight so that it will be in a state of neutral equilibrium if the spring under the arm is removed. Consequently the spring when in place will be the only factor determining the stylus pressure. The pickup arm, has compensation for the ingoing force - "skating effect" - arising on account of interaction between the offset angle and the friction between stylus and gramophone record, so that the stylus will exert equal pressure on both groove walls. This is of great importance when playing stereo records, in which each groove wall contains its separate signal.

The B&O type ST/L15 pickup arm is 223.5mm long and stylus pressure is adjustable between 1 and 4 grams. Awarded the Danish D-Prize as well as the German iF Prize for excellent design.

und

ST/M - Montageabstand 190 mm - effekt. Länge 205 mm - Überhang 15 mm
ST/L - Montageabstand 209,5 mm - effekt. Länge 223,5 mm - Überhang 14 mm
ST/P - Montageabstand 310 mm - effekt. Länge 320 mm - Überhang 10 mm
ST/A - Montageabstand 209,5 mm - effekt. Länge 223,5mm  - Überhang 14 mm

Für den Arm ST/A war wohl ursprünglich das hauseigene System SP1 vorgesehen und diese Tonarme konnten seinerzeit mit dem Beogram 3000 - also in der Version 5210 mit dem TD-124 oder der Version 5211 mit dem Acoustical 3100 in der B&O Zarge geordert werden.

Das B&O SP1 war ein MM-System mit 7 mV Ausgangsspannung und einer 8er Compliance, hatte einen sphärischen Nadelschliff mit wahlweise 17µ (Mono & Stereo) oder 12 µ (nur Stereo) Nadelverrundung.
Somit müßte der Tonarm also eigentlich zu den schwereren Vertretern gehören ... rechnet man mal auf Basis der zum SP1 bis SP8 bekannten Daten zurück und nimmt die für das optisch baugleiche SP8 angegebene 10 gr. als TA-Masse, so müßte der ST/A eine effektive Masse von ca. 37 gr. besitzen ...

... anders herum fallen bei einer Comliance von 8 auch schon alle heutigen MMchen aus der Liste raus ... es blieben nur MCs oder eben die alten Klassiker wie Shure M3D, ELAC STS222 und Co.

... das hat natürlich auch seinen echten Reiz ...