78 rpm Calibration Disc Set


AES Standards provides a rare opportunity to calibrate playback equipment for 78 rpm coarse-groove records

Recognising an international need for calibration tools, the AES Standards Working Group on Transfer Technologies (SC-03-02) initiated a project to calibration playback equipment for coarse-groove 78 rpm records. The result is now available as a boxed set of two identical 12-inch vinyl discs, catalogue number AES-S001-064. The two discs allow one to be used as a day-to-day working tool while the other may be stored as a master reference.

This calibration disc set is important because:

  • It will confirm playback calibration according to International Standard IEC 98 Edition 1 (1958) and Edition 2 (1964) for coarse-groove records;
  • Many different recording characteristics were used historically on earlier 78 rpm discs. Also, many earlier coarse-groove discs were cut at nominal speeds different from 78 rpm. Unless the reproducer can be calibrated at a known speed, there can be no objective basis to decide what playback equalization characteristic will be appropriate or correct;
  • Calibration discs have become rare since they were first made in the 1950s;
  • Archives and libraries throughout the world will to be able to calibrate their disc reproduction chains consistently and interchangeably;
  • Smaller transfer and restoration businesses will be able to offer a service calibrated to international standards;
  • Private collectors will be able to refine their appreciation of their vintage collections.
Gliding tone, 20 Hz to 20 kHz
Speed: 77,92 rpm
Lateral (mono) coarse groove
Time constants; 3180/450/0 ms
Separate outer & inner bands:
   1 kHz trigger tone
   Gliding tone, 20 Hz to 20 kHz
   1 kHz reference level*
   *20 mm Light Band Width (LBW);
   approx 8 cm/s peak-to-peak, 5,7 cm/s rms
Single tones,18 kHz to 30 Hz
Speed: 77,92 rpm
Lateral (mono) coarse groove
Time constants: 3180/450/50 ms
(Pressed under license from EMI Records Ltd.)

Further details on the content, origins, and use of this Calibration Disc Set may be found on the AES Standards Web site.

This is a limited pressing of 500 sets in highest-purity vinyl. When this batch has gone, we hope to be able to order a second pressing. Because the supply of suitable vinyl material, and the availability of coarse-groove pressing, to achieve reference quality is becoming scarce, we cannot guarantee that these discs will be available in the future. If coarse-groove records are important to you, you should act now.

IMPORTANT: This is a vinyl pressing and is not for use with mechanical reproducers or earlier electrical pickups using steel styli. Use a lightweight pickup only.

Click Here to Purchase This Set

AES - Audio Engineering Society