Reverb Tank Ohm Confusion

[thisisnickpaige]

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?

[øøøøøøø]

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

[thisisnickpaige]

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.

[øøøøøøø]

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

[thisisnickpaige]

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