I've done a fair bit of googling with no definite answer. The code is 137 746N It's a 32 ohm speaker. Obviously a CTS Alnico.. but from what year? I saw in one obscure website that the "N" designates "Concert series". Does the date code indicate 46th week of 1967? 1977? Thanks for any help!
I think those 32 ohm ones came from the PA-100 speaker columns. Could be a Bassman 10, too, though I haven't seen those speakers in one.
Weekend bump to the top hoping someone knows about these speakers. I got 4 of them and wired them in parallel (for 8 ohms) and they sound very very good with my SR head (has an 8 ohm tap). Classic CTS Alnico tone!
How the Source-Date Code Works. The source-date code on a pot is a 6 or 7 digit code impressed into the casing of the potentiometer. For speakers this code can be 5, 6, 7 or 8 digits long, and it's ink-stamped or paint-stamped on the "bell housing" of the speaker. In either case, the code works the same. The first 3 digits on a pot, or the first 2, 3 or 4 digits on a speaker are the source or manufacturer code. The remaining 3 or 4 digits are the date code. In 3 digit dates code, the 1st digit is the last digit of the year. On 4 digits date codes, the 1st and 2nd digits are the last two digits of the year. In either case, the remaining 2 digits are the week of manufacture (01 to 52). With this in mind, remember if the last two digits of the source-date code are greater than 52, you're not looking at the source-date code. So it would be asafe bet they are from 67 IMO. I think they went to 7 digits around 68.
CTS made the 46th week of '67. I have 2 of these and they came from an old Fender 4-10 PA column. My speakers are 68's. 32 ohm. If I ever use mine, I'll probably get them reconed to 8 ohm. I really didn't add anything but responded just for support.