The following from Copeland's manual has always puzzled me, and I wonder
if anyone can shed light on the reference to "Victor’s then-unique  
use of multiple
limiters (essentially one on each mike)", since I've never heard of  
this from any other
source.  This may originate in Ref. 60, Wireless World (1941), which  
I have not
seen.  RCA Victor may have experimented with limiters in 1941, but  
Copeland's
statement can leave the impression that this was common practice.

> 6.71 Various RCA characteristics
> Ref. 60 (July 1941) is the earliest contemporary reference I have  
> found which describes RCA Victor using pre-emphasis on its 78s,  
> although the time constant was not given. Straight listening  
> suggests the idea was tried somewhat earlier, and we saw in section  
> 6.23 that Moyer wrote about RCA’s Western Electric systems with pre- 
> emphasis at 2500Hz (corresponding to 63.6 microseconds); but I am  
> deeply sceptical. It seems to me far more likely that, if something  
> which had been mastered direct-to-disc was reissued on microgroove,  
> the remastering engineer would simply have treated everything the  
> same. And I consider it likely that judging by “pure sound” clues,  
> Victor’s then-unique use of multiple limiters (essentially one on  
> each mike), would itself have resulted in a “brighter” sound.


Doug Pomeroy