What does the "B" on the end of the Mesa T numbers mean?
An IR maker had this to say and the link is the clip he made:
https://soundcloud.com/mlsoundlab/v30s- ... -different
"First is a Mesa V30 from around 2004, second one is a Mesa V30 from about 2010 (still made in UK custom for Mesa), third one is a V30 from before they started making them in China, not sure what the age was.
I have a ton of respect for Celestion as they make the best sounding speakers out there but I think it would be bad for their business to say anything has changed in the V30 design. Yet if you go through the spec list of Celestion's own notes you can see 7 different design codes for the Vintage 30 speakers (wow the bygonetones website has been pulled down..
http://www.bygonetones.com/ this was the website that had all this information on it) which makes me thing they've changed the design in a big way at least 7 times. That is very true to my experience of owning over 20 4x12 cabs that supposedly should sound the same.
The MEGA OVERSIZE pack that @Gavin just mentioned has indeed the most original V30 speakers that I've ever found during about 6-7 years of collection guitar speakers and cabinets. They still have the serial code stamps on the metal and none of those sticker tags that they started using later on. These speakers are not in the clip above as I don't have the cab here right now.
EDIT: Luckily I have backups of that website. Here's the list of different manufacture codes that are all called the "Vintage 30" by Celestion:
T3896 <--- this is the Marshall spec V30 8 ohm version
T3897 <--- this is the Marshall spec V30 16 ohm version
T3903 <--- "normal" V30 8 ohm
T3904 <--- "normal" V30 16 ohm
T3987 <--- Marshall OEM (known to be a little brighter than the standard V30)
T4335 <--- this is the original Mesa spec V30
T4335B <---- this is a newer Mesa V30 that's still supposedly made in UK
T4416 <--- this is the original Mesa spec V30 16 ohm version
You will see the letter B behind some of these serial codes. I've just started calling it short for "bad". These speakers are usually the ones that look like they're made in the UK when they're actually not.
I would like to emphasize that this is not a tonewood-like discussion where you question if it's real or not. This is very real and I can definitely get other IR producers that agree with me confirm that there are very different V30's out there. There's even some rumors of Orange getting their V30s custom made by Celestion with another modification."
From this thread:
https://forum.fractalaudio.com/threads/ ... rs.146589/