by Keith Wright
Excerpts from Part 2 of Keith Wright's excellent article on the history of the 45 rpm record player:
Software Medium: Speed Limits
I have three stories for why the 45 turns at that speed. In the first, "The 45 rpm speed
was the only one to be decided by a precise optimisation procedure (by RCA Victor in 1948). Calculus
was used to show that the optimum use of a disc record of constant rotational speed occurs when the
innermost-recorded diameter is half the outermostrecorded diameter. That's why a 7-inch single has a
label 3 1/2 inches in diameter. Given the CBS vinyl groove dimensions and certain assumptions about the
bandwidth and tolerable distortion, a speed of 45 rpm comes out of the formula." (Quoted from
Copeland - although the research actually sounds like the work done by Maxfield et al at Bell Labs not RCA.)
In the second story, "J. P Maxfield analy[zed] the compromise between signal-to-noise ratio and came
up with 33 1/3... Maxfield's analysis still applies: the 45 'single' was RCA's equivalent to a 10-inch, 78
rpm record, only smaller." (Brack-Nanestad)
The third story holds, "RCA Victor came up with a 7-inch vinyl disc with microgrooves, rotating at 45 rpm,
a speed chosen specifically to make the most of the music, unlike 78s or 33 1/3s." (Worsley)
The Phony War to R.I.P.
The date generally cited for launch of the RCA 45 is March 31, 1949. Some cite an earlier date,
but prior to this the RCA Distributor's Record Bulletins had only records with number starting with 20,
21 and 22. They were all 78s! There were no 45s available for some weeks yet! The period right after
release and up to the RCA 'capitulation' (with RCA's acceptance of the LP in January, 1950) is generally
called 'The War Of the Speeds' but I call it a phony war. Both formats would remain healthy well into the
80s. Each had a niche, but it may have taken some executives a while to realize this.
RCA seems to have hit a 'speed bump' early in the war until it realized that 45s were not for multi-record
classical albums mimicking those of the 78 era - they were selling more to listeners interested in single
songs. Younger people in particular were more interested in spending less to hear just their 'hits' on
cheap players. This swing is evident to me by the three players available from RCA in the second year of 45
In 1950, there were three players available that did exactly the same job:
- The original 9-JY radio attachment (I hear that those over 50 may also remember using the TV) of 1949
was re-branded the 45-J-1 in 1950. This had Carson's original X-changer (RP-168) with a number of brass
- The 45-J-2 attachment was new from the ground up. It sported a brand new changer (RP-190) with more
plastic parts and was built by a third-party, Crescent.
- The 45-J-3 was ALSO a new attachment built from the ground up. It sported yet another brand new changer
with brass parts (RP-193) and it was also built by a third-party, Oak. The J-3 is the most interesting
looking 45 player RCA marketed (other than the Berkshire attachment). It has a swooping metal tone arm
and more interesting 'cosmetics'. It is not the 'appliance' the J-2 appears to be.
Briefly the evolution of the RCA players is:
- As noted, the original 1949 player model numbers started with '9'.
- In 1950 they changed to '45' and the 'E' line was moved down a notch with the 9-EY-3 being replaced
by the 45-EY-2 while the 45-EY-3 received a lid.
- In 1955 models started with '6' and included a number of cost-cutting measures. This was also the
year that Carson's new single-play model was introduced, the Slide-O-Matic, which accepted the record
through the front.
- In 1956, models starting with '7' and '8' sported better sound through ceramic cartridges, beefed-up
amplifiers and-in some cases-separate woofer and tweeter speakers. The new players of 1956 should be
avoided, as they are the result of even more costcutting measures and have been "regarded as
downright cheap". Clearly, profits were going down for machines to play only 45s.