Dating rola celestion speakers
In 1982, Celestion broke new ground in loudspeaker technology when they presented the SL6, a compact hi-fi speaker featuring the first ever metal dome tweeter, made of copper and designed with the help of laser interferometry.
They followed this model up with the SL600, which used rigid honeycomb alloy called Aerolam instead of wood in the speaker casing; a material previously used only in the aerospace industry.
If I want to bring up the headroom I could swap the tubes.
Celestion Radio Company and Celestion Limited were formed in 1927, and two years later the company moved across the Thames to Kingston.The 6 digit code indicates what manufacturer made the speaker and when it was made. Here is a list of some of the speaker manufacturers and their EIA codes: So, the speaker in the image above would have been made by Jensen (220) during the 27th week of 1951 or 1961.