Tone Arm Balance

Radio Record, Volume III, Issue 49, 20 June 1930, Page 8

Tone Arm Balance

FLOW often is it stated that one of the advantages of gramo-radio or of electrical gramophone reproduction §& the fact that record wear is reduced. The reason put forward for this is that a pick-up does not require su a great point pressure of the needle upon the record, that with most pick-up arms this pressure can be easily regulated, and that the actual grinding of the surface is reduced. ~ This sounds as though it might gladden the heart of gramo-radioites, for the cost of records is the biggest item of upkeep; but it is only a half-truth. Record wear can be reduced; the important thing to remember is that sometimes the reduction in wear is so slight as to be not worth the trouble, and that sometimes the reduction in wear ean be obtained only at the expense of quality. The pressure upon the record surface in an ordinary mechanical-reproduction gramophone is in the nature of several pounds per square inch. It should be constant, but with most records it is nothing like constant; and this is often the cause of jarring on very high, very low, or very loud passages. Obviously, then, there is a certain minimum pressure beyond which one cannot safely go. Below that minimmum, very bad results will be experienced, with generally lower voltage swings delivered in the case of a pickup, and in bad cases the needle may jump the groove, Beware of this, then, when adjusting a counterbalanced arm, The tendency is all towards electrieal recordings of greater brilliancy, and with most of the new records a pressure upon the record, in the case of a pickup, not much Jess than that with an ordinary soundbox will be needed; so there is no saving in record wear. With adjustable tone-arms the pressure can be réduced for the more valuable records.-N. Bell, in "Wireless Magazine." — capisamminmasgeseminenette sneuitnteiraneineampoammandanait