IEC 60098-2020 pdf download.Analogue audio disk records and reproducing equipment.
10.1.4 Pickup operation
The following information shall be provided:
a) stylus force in mN; statement in gm-force may be added;
b) load impedance per channel, expressed as a parallel combination of resistance in kO and capacitance in pF;
C) external correction network (if required):
d) external equalization network (if required).
Before any measurements are taken, the unit shall operate for at least the recommended time for stabilization and all measuring equipment shall have reached temperature stability.
The output of the unit shall be taken from the correction or equalization network (it any) i.e. the measurement shall be made at that point where the signal has the characteristic that is to be reproduced. For stereo pickups, both channels shall be terminated in accordance with Item b) above. Apart from that load, the measuring equipment shall not introduce an additional load that would significantly affect the characteristics to be measured.
10.1.5 Test records
It a test record is used for any measurement, it shall be identified by catalogue number, name of manufacturer and country of manufacture.
Information on test records Is given in Annex A, Annex B. Annex C. Annex 0 and Annex E.
NOTE In order to achieve comparable results, test records for a particular purpose should be derived from the same original recording. However, even given this condition, variations in record manufacture, such as record material and pressing conditions, can give rise to variations in characteristics such as high-frequency characteristics, separation characteristics, wow, flutter and rumble.
10.2 Methods of measurement
10.2.1 General
The methods of measurement apply to complete record playing units only. If measurements are made on components of record playing units (e.g. turntables, pickup cartridges), the precise details of the remaining parts of the record playing unit used for measurement shall be stated in the test report.
The sensitivity of the measuring equipment shall be sufficiently independent of frequency to achieve the required accuracy of measurement.
10.2.4 Wow and flutter
Specification: see IEC 60386 for full details.
Method: a test record (see Annex B) containing a lateral signal of 3 150 Hz is centred with respect to the rotational axis of the unit by means of a concentric groove situated near the edge of the record. The 3 150 Hz band is played, and the output is fed to a measuring instrument, in accordance with IEC 60386.
Units without speed adjustment are measured at the actual speed; those with speed adjustment are measured at the rated speed.
Result: weighted wow and flutter = arithmetic mean of at least three meter readings.
10.2.5 Maximum start time to reach actual or rated speed
Specification: the maximum time that has elapsed between the operation of the starting device and the disk speed being increased from zero to the speed that gives a wow and flutter value which is twice the steady state value.
Method:
A test record (see Annex B) containing a signal of 3 150 Hz is played with the pickup at the beginning of the recording. The reproduced test signals shall be fed to a frequency discriminator centred on 3 150 Hz and the output from the discriminator fed to a graphic recorder or storage oscilloscope. The time taken from the operation of the starting device to when the trace on the recorder reaches twice the steady-state wow and flutter value is noted. The measurement is repeated several times.
Result: the maximum time shall be stated In s.
10.2.6 Signal/rumble ratio
For all measurements in this subclause, the frequency characteristic of any correction and/or equalization network external to the unit under test shall, between 2 Hz and 2 kHz, not deviate by more than —1 dB from the rated reproducing characteristic, taking as a reference point the value at 1 kHz.
Specifications:
a) Signal/rumble ratio:IEC 60098-2020 pdf download.Analogue audio disk records and reproducing equipment