Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: vintasonic on May 27, 2022, 07:26:30 pm

Title: EH Date Codes?
Post by: vintasonic on May 27, 2022, 07:26:30 pm
I always refer to the 4 digits on an EH tube as the date code & have always assumed it was YY-WW.  But I have also always had suspicions I was wrong, since that doesn't always seem to make sense - sometimes the codes seem unlikely.

Could someone verify or set me straight?

Thanks

Mark Springer
Vintasonic
Title: Re: EH Date Codes?
Post by: tubeswell on May 27, 2022, 08:41:29 pm
Ask New Sensor.
Title: Re: EH Date Codes?
Post by: vintasonic on June 01, 2022, 01:44:23 pm
I did try to contact my rep at EH but never got an answer.  Since I am no longer purchasing EH tubes, I don't have an actual contact there.  I thought somebody here might know the answer.
Title: Re: EH Date Codes?
Post by: HotBluePlates on June 01, 2022, 03:36:39 pm
I always refer to the 4 digits on an EH tube as the date code & have always assumed it was YY-WW.  ...

Me too.  I see this tube as "12th week of 2006" (https://www.tube-town.net/ttstore/images/product_images/popup_images/71_0.jpg).

... that doesn't always seem to make sense - sometimes the codes seem unlikely. ...

Like what?

52 weeks in a year, I bet you'll see "01" to "52" in the 2nd pair of digits, nothing higher than "22" in the 1st pair of digits.
Title: Re: EH Date Codes?
Post by: vintasonic on June 01, 2022, 06:56:50 pm
Confusing in that tubes that I have purchased last year have date codes like 07 09 (12AX7) and 16 07 (6V6).  Considering the volume of tubes sold, I wouldn't expect to get 12AX7s from 2007 - or 6V6 from 2016
Title: Re: EH Date Codes?
Post by: tubeswell on June 01, 2022, 11:19:09 pm
Confusing in that tubes that I have purchased last year have date codes like 07 09 (12AX7) and 16 07 (6V6).  Considering the volume of tubes sold, I wouldn't expect to get 12AX7s from 2007 - or 6V6 from 2016


Depends on how long whoever was on-selling the tubes had them stashed in some warehouse or other I guess
Title: Re: EH Date Codes?
Post by: vintasonic on June 03, 2022, 02:42:14 pm
Direct from EH?