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Accutronics Reverb Tanks


Accutronics makes several types of tanks, but the three types most commonly found in mass produced amps are the 4, 8, and 9.

The type 4 is 17" long and is commonly called a "2 Spring" even though it actually uses 4 springs joined together to form 2. This is the type most often found in Fender Amps.

The type 8 is 9" long and is commonly called a "3 Spring". This model actually uses 6 springs joined together to form 3. This is the type most often found in Marshall Amps.

The type 9 is 17" long and is commonly called a "3 Spring". Again, this model actually uses 6 springs joined together to form 3. These are most commonly found in Mesa Boogie Amps or used as an aftermarket upgrade for Fender Amps to increase the reverb characteristics over the stock 2 spring model.

Accutronics part numbers consist of 7 characters as described below.

1st character: Type (ie. 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/SLM/Ampeg 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 9" 3 10ohms/.81ohms 2575ohms/200ohms
8BB2A1B SLM 9" 3 190ohms/26ohms 2575ohms/200ohms
8DB2C1B Marshall 9" 3 310ohms/36ohms 2575ohms/200ohms
8EB2C1B Fender 9" 3 800ohms/58ohms 2575ohms/200ohms


Accutronics reverb tanks are made by:

Sound Enhancements, Inc.
185 Detroit St.
Cary, IL 60013