Dating Mustard caps?

[JamesHealey]

anyone know how to read the date code?
i've got some that say "B0W"

any ideas?

[Sparky]

I seem to remember reading that the middle digit was the year ie 0 would mean either 1960 or 1970.

[neikeel]

The first letter is the quarter of the year

A first
B second
C third
D fourth

number is year, ie 7 = 1967

0 is 1970

the last letter I do not know

I have some 33P whatever that means

[JamesHealey]

cool thanks guys well that helps me date my marshall to 1970, it looks like a 69 in some respects but it cannot be if the mustards were made in 2nd quarter of 1970.

[Bunnest]

If its an "A" series, the last one for '69 would be serial number A4135. That is my SuperBass number, with the date tag of 31/12/69. I would guess that after 4135, or surely after 4200, it is a '70. Best series after the plexis, and mine actually has a plexiglass faceplate (probably new years eve cheer!)

[Bluesgeetar]

What would A4P be?

[JamesHealey]

first quarter of either 64 or 74, Im not sure how u'd be able to tell them apart but if they came from a superlead it's 74 or JTM45 it's 64 I guess.

[Bluesgeetar]

They actually haven't came from an amp. I bought a bunch from this guy. They are .68uf 160v NOS. So they haven't even seen an amp. But they will.

[Bunnest]

most likely 74. NOS would, most likely, be the last ones on hand. Logically. Also, if you look closely at early to mid 60s caps, esp. the .022s, they seem a tad bit fatter...