Reverb Tanks Explained

Author: Kevin  

Need more information about your reverb tank?

Reverb Tanks Products and Specifications

There are a number of different types of reverb tanks available. Use this guide to help you determine part number based upon your specifications and application.
Tech Corner Image - Accutronics Type4

Type 4

The industry standard for years, the type 4 is still manufactured today using Hammond’s original design. Four counter-wound and coupled springs deliver superior mechanical performance and the classic sound that helped make the Fender Twin Reverb amp famous. Outer channel dimensions are 16.75″ length x 4.735″ width x 1.313″ height.
Tech Corner Image - Accutronics Type8

Type 8

Designed for applications in which the overall sound quality is important and a compact package is required. Small in size, this three-spring reverb approaches the rich textural quiality of the larger reverb units. Outer channel dimensions are 9.25″ length x 3.375″ width x 1.313″ height.
Tech Corner Image - Accutronics Type9

Type 9

Six springs, counter-wound, coupled and placed in parallel, combine to create Sound Enchancement’s fullest, richest reverb effect throughout the full range of musical sound. Ideally suited for keyboard, sound reinforcement and pedal steel applications. Outer channel dimensions are 16.75″ length x 4.375″ width x 1.313″ height.
 

Size Comparison

Part Numbering System

Reverb tank part numbers consist of a seven digit code, ie 4EB2C1B. Each digit in the part number represents a specification. The meanings of these digits are as follows:
Digit Specification
1st Reverb Type
2nd Input Impedance
3rd Output Impedance
4th Decay
5th Connectors
6th Locking Devices
7th Mounting Plane

Part Numbering Specifications

Value Type 1 or Type 4 Type 8 or Type 9
Digit #1 – Reverb Type
1 Type 1  
4 Type 4  
8   Type 8
9   Type 9
 

 

Digit #2 – Input Impedance

A 8 Ohms 10 Ohms
B 150 Ohms 190 Ohms
C 200 Ohms 240 Ohms
D 250 Ohms 310 Ohms
E 600 Ohms 800 Ohms
F 1,475 Ohms 1,925 Ohms
 

 

Digit #3 – Output Impedance

A 500 Ohms 600 Ohms
B 2,250 Ohms 2,575 Ohms
C 10,000 Ohms 12,000 Ohms
 

 

Digit #4 – Decay Time

1 Short (1.2 to 2.0s)
2 Medium (1.75 to 3.0s)
3 Long (2.75 to 4.0s)
 

 

Digit #5 – Connectors

A Input Grounded/Output Grounded
B Input Grounded/Output Insulated
C Input Insulated/Output Grounded
D Input Insulated/Output Insulated
E No Outer Channel
 

 

Digit #6 – Locking Devices

1 No Lock
 

 

Digit #7 – Mounting Plane

A Horizontal, Open Side Up
B Horizontal, Open Side Down
C Vertical, Connectors Up
D Vertical, Connectors Down
E On End, Input Up
F On End, Output Up
 
Example: 4EB2C1B
 
Consulting the table below, we can see that a 4EB2C1B can be broken down in the following way:
  • Digit #1 = 4, meaning this is a Type 4 tank
  • Digit #2 = E, meaning the input impedance for this tank is 600 Ohms
  • Digit #3 = B, meaning the output impedance for this tank is 2,250 Ohms
  • Digit #4 = 2, meaning the decay time for this tank is Medium
  • Digit #5 = C, meaning the connectors on this tank are Input Insulated / Output Grounded
  • Digit #6 = 1, meaning there is no locking device
  • Digit #7 = B, meaning the mounting plane is Horizontal, open side down

 

Example: 8EB2C1B        

Consulting the table above, we can see that an 8EB2C1B can be broken down in the following way:

  • Digit #1 = 8, meaning this is a Type 8 tank
  • Digit #2 = E, meaning the input impedance for this tank is 800 Ohms
  • Digit #3 = B, meaning the output impedance for this tank is 2,575 Ohms
  • Digit #4 = 2, meaning the decay time for this tank is Medium
  • Digit #5 = C, meaning the connectors on this tank are Input Insulated / Output Grounded
  • Digit #6 = 1, meaning there is no locking device
  • Digit #7 = B, meaning the mounting plane is Horizontal, open side down

 

 

 

 

 

 

 

*information sourced from amplified parts