RECENT ADVANCES IN WAX RECORDING 



167 



playings shown in Fig. 9. They show little change in the low frequency 

 response and a loss of about 2 TU per playing at high frequencies. 

 The practical value in studio work of being able to let an artist immedi- 

 ately hear and criticize the results of his own efforts can hardly be 

 overestimated. 



500 1000 



FREQUENCY 



Fig. 8 — Response of a "wax playback" driven by constant velocity wax record. 



600 1000 



FREQUENCY 



5000 10000 



Fig. 9 Loss in response on successive playings of a wax playback driven by constant 



velocity wax record. 



Copying (Processing) of the "Wax" Record 



After a groove has been satisfactorily cut into the "wax" record, 

 the usual procedure is to render the surface of the "wax" conducting 

 by brushing into it an extremely find conducting powder. It is then 

 electroplated. The technique in this step varies somewhat with the 



