THE GREAT MULLARD MAGIC BLOG — MAZDA MO

Well, Mazda were another manufacturer who wanted to stand out and indeed made their own version of the Octal base with a fatter spigot known as the Mazda Octal or MO base.    Their valve numbering system was a bit kooky too and needs some explanation.  The typical Mazda valve type number was an alphanumeric affair comprising of; a numerical prefix followed by a letter which in turn was followed by a mumerical suffix. The numerical prefix always indicated the heater voltage EXCEPT where 10, 20 & 30 were used which indicated the heater current draw in 0.1A.  A further...