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Most Beocords of this type has a level setting switch at the back, near the DIN socket for switching between Line/DIN level.
Furthermore, some Beocords/Beomasters have been converted for use with other levels.
Alternatively, you can make up an adapter with two voltage dividers to take the level down a bit.
Normally, the record level sliders will be near the 4-5 markings when recording.
Martin