OffsetGuitars.com

Am i reading this wrong?

So i inherited a Princeton Chorus amp that needs a new tank. Code is: 8EB2C1B.
Online i found this hella detailed website.

I scroll down to the code chart to find the correct impedances: type 8EB and 9EB need 800Ω in, 2.575kΩ out, cool. But then here they state, " As long as the last 6 digits are the same, type 4AB3C1B and type 9AB3C1B tanks are interchangeable, ". But the chart doesn't seem to read like that. There could be up to a 200-500Ω difference in impedances depending on the letter. Maybe that's nothing, but it doesn't seem to 'match'.

If that is in fact correct, could i use a 4EB3C1B in my amp? A longer tank would physically fit, and I'd prefer a more classic Fender 2 spring Twin Reverb sound. I know the reverb circuits are different, but with the 2 spring tanks the notes seems to sit a bit more in front of the reverb to my ear.

Anyone that can help clarify?

Impedance is pretty critical

I’d reach out to Accutronixs directly, I’m sure they’ll be able to offer clarity about their part numbers

That was my take as well, so I was surprised. It wasn’t just on their website, it was on many that I found; most places say as long as the last six digits match, you’re good.

So, confusing.

It’s been awhile since I checked, but I thought the first few characters were about decay time, number of springs, etc

Yup, pretty spot on. Everyone seems to agree that it’s deciphered as follows:
1 digit: Pan size & number of springs
2 digit: Input impedance
3 digit: output impedance
4 digit decay time
5 digit: in/out connection (grounded, shielded, etc)
6 digit: locking device (yes/no)
7 digit: how it’s mounted