 
Accutronics reverb tank numbering system
The type 4 is 17" long and uses 2 long springs,
each of which consists of two springs joined in the middle. Thus, Accutronics
considers this model a 4spring unit. This type was the original style selected
by Leo Fender. The type 8 is 9" long and uses 3 springs. This type is most
famous for its use by Marshall™ . The type 9 is 17" long and uses 3 long springs,
each of which consists of two springs joined in the middle. Analogously,
Accutronics considers this unit a 6spring device. All Accutronics part numbers
consist of 7 characters as described below.
1st character: type 4, 8, or 9
2nd character: Input impedance @ 1kHz
Type 
A 
B 
C 
D 
E 
F 
4 
8 ohms 
150 ohms 
200 ohms 
250 ohms 
600 ohms 
1475 ohms 
8 and 9 
10 ohms 
190 ohms 
240 ohms 
310 ohms 
800 ohms 
1925 ohms 
3rd character: Output impedance @ 1 kHz
Type 
A 
B 
C 
4 
500 ohms 
2250 ohms 
10000 ohms 
8 and 9 
600 ohms 
2575 ohms 
12000 ohms 
4th character: Decay time
1 = short (1.2 to 2 sec)
2 = medium (1.75 to 3.0 sec)
3 = long (2.75 to 4 sec)
5th character: Connector arrangement
A = input grounded, output grounded
B = input grounded, output insulated
C = input insulated, output grounded
D = input insulated, output insulated
6th character: Locking device 1 =
no lock
7th character: Mounting plane
A = horizontal,open side up
B = horizontal, open side down
C = vertical wall, long axis horizontal, connectors up
D = vertical wall, long axis horizontal, connectors down
E = vertical wall, long axis vertical, input up
F = vertical wall, long axis vertical, output up
The following table summarizes the above data
for the most commonly available units:
PART NUMBER

PRIMARY USER

LENGTH

NUMBER OF SPRINGS

INPUT IMPEDANCE@ 1KhZ/DC

OUTPUT IMPEDANCE @ 1KhZ/dc 
4AB3C1B 
Fender 
17" 
4

8ohms/.81ohms 
2,250ohms/200ohms 
4BB2C1B 
Acoustic/Ampeg/Crate™ 
17" 
4

150ohms/26ohms 
2,250ohms/200ohms 
4EB2C1B 
Peavey™ 
17" 
4

600ohms/58ohms 
2,250ohms/200ohms 
4FB3D1B 
Music Man / General 
17" 
4

1475ohms/200ohms 
2,250ohms/200ohms 
9AB2C1B 
Fender™ / Boogie 
17" 
6

10ohms/.81ohms 
2575ohms/200ohms 
9EB2C1B 
Peavey™ / General 
17" 
6

800/58ohms 
2575ohms/200ohms 
9FB2A1C 
General 
17" 
6

1,925/200ohms 
2575ohms/200ohms 
8AB2A1B 
Boogie, PRS 
9" 
3 
10ohms/.81ohms 
2575ohms/200ohms 
8BB2A1B 
Ampeg™ / Crate 
9" 
3 
190ohms/26ohms 
2575ohms/200ohms 
8DB2C1B 
Marshall™ 
9" 
3

310ohms/36ohms 
2575ohms/200ohms 
8EB2C1B 
Fender 
9" 
3

800ohms/58ohms 
2575ohms/200ohms 
