The History of Spring Reverberation

When Laurens Hammond introduced the first Hammond Organ in 1935, most people were only familiar with the traditional pipe organs the had heard at churches and theaters. So, when they purchased a Hammond for their homes, they expected the same room filling sound they had come to know and love. Of course, in their thickly carpeted living rooms with low ceilings and drapery covered windows, they didn’t get it.

Thus, Laurens Hammond needed to find a way to add reverberation to the living room. He discovered that Bell Labs had devised an electromechanical device to simulate a single delay experienced on long distant calls. The device used two springs to transmit the delaying signal and four additional springs to dampen and “center” the driver saddle. While the dampening were housed in long tubes filled with oil, one of the springs transmitting the delay signal ended in a short tube which, by varying the amount of oil in the tube, varied the decay time. After modifying the reverb to create many echoes, it was perfect for Hammond’s needs.

At the time, the unit stood four feet tall. But size was not a problem because all Hammond organs came with a separate tall Tone Cabinets which contained speakers and reverb unit. As time went by, though, Tone Cabinets became shorter or unnecessary with smaller, self-contained organs. Three Hammond Organ Company engineers, Alan Young, Bert Meinema and Herbert Canfield, developed the necklace reverb, so-named because the springs hung in the same fashion as a necklace. Introduced in 1959, the necklace reverb was about 13 inches wide, 1 inch deep and 14 inches tall. The metal framework, or housing, was shaped like a “T” and the springs drooped from one end of the horizontal “T” line to the other, creating a necklace effect. This improvement made the reverb unit smaller, lighter, less expensive and more natural sounding, yet it had one annoying problem: when the unit was jarred or shaken, the springs would bang against each other and/or the metal “T” frame. This created a thundering, crashing sound in the speakers, something that in the 1950s was definitely not part of the act. Nor was it acceptable in Grandma’s living room.

In 1960, Alan Young was again assigned with the task of developing yet another reverb unit that would solve the previous units’ problems. A fine engineer, Young was also a musician who frequently took projects home to experiment at night and on weekends. Since Young wanted a reverb unit to be no bigger than his brief case, his efforts resulted in what is now called the Accutronics Type 4 reverb unit.(At this time it was the Hammond Type 4.) With the bugs worked out, the new unit caught on with organ makers and anyone else requiring reverberation. One such customer was Leo Fender, maker of Fender guitars, who added the Type 4 to his now famous Fender Twin Reverb. With that type of endorsement, the Type 4 became the industry standard.

By 1964, the increasingly busy Hammond Organ Company had run out of room to produce the reverb units. So Hammond moved production to another Hammond-owned unit, Gibbs Manufacturing, in Janesville, Wisconsin. In 1971, the reverb business moved again to another Hammond unit, AccutronicsⓇ, in Geneva, Illinois. Meanwhile, employees at Gibbs decided to start making their own reverb manufacturing company called O.C. Electronics, giving Accutronics major competition in the reverb market. Many service technicians still recall O.C. Electronics because of the popular sticker attached to each of their units stating: “Made by Beautiful Woman in Janesville, Wisconsin.”

Not long after the move to Geneva,Illinois, Accutronics developed smaller reverb units- the 2 spring Type 1 reverb and 3 spring Type 8. These two new reverb units were just over nine inches long, down from a length of 17 inches. As manufacturers have continued to design smaller amps, smaller reverb units have gained favor and market share.

In 1974, Accutronics, still a division of Hammond Organ, acquired a printed circuit boards maker in Cary, Illinois, which was renamed Accutronics.(Meanwhile in1977, Hammond Organ became a member of the Marmon Group of companies, a Chicago-based association of manufacturing and service companies.) In 1982, the two operations were combined in the Cary plant. By this time, the reverb units were beginning to be known as “the Accutronics Reverb” and the founder of O.C. Electronics was getting ready to retire. In late 1985, Accutronics acquired O.C., once again uniting the two companies trained in the design and manufacture of the original Hammond reverb units.

In 1990, the reverb division had outgrown it’s home in Cary, so it was moved to a new 37,000 square foot plant across town and renamed Sound Enhancements, Inc. (Sound Enhancements also includes the Morley line of special effects pedals and stomp boxes and swithces, which was purchased in 1989.)

In 2005, the company changed its name to Sound Enhancement Products, Inc. and continued makes the world-famous Accutronics Reverb for such major amplifier manufacturers as Fender, Marshall, Peavey and others. Despite the introduction of digital reverb several years ago, Accutronics reverb business continues to grow because of its warm, true sound, its reliability and its great reverberation since 1939.

Today, Accu-Bell Sound still makes the world-famous Accutronics Reverb for such major amplifier manufacturers as Fender, Peavey, Marshall and others. Despite the introduction of digital reverb several years ago, Accutronics’ reverb business continue to grow and keep because of its warm, true sound, its reliability and its tradition of great reverbration since 1939.

In 2009, the friendly acquistion of AccutronicsⓇ Brand and Assets from Sound Enhancement Products Inc. by Belton Engineering Co., Ltd.. There are no immediate plans to change the manufacturing source, delivery will not change without improvement. All of manufacturing was then transferred to Belton reverb and the Engineering staff followed to train the new owners on how to continue on th produciotn of Accutronics reverbs with the same degree or upgrade of quality AccutronicsⓇ is famous for Accu-Bell Sound Inc. is commeitted to producing the finest Electro Mechannical Spring reverbs in the world and continue on with the long heritage starged by Hammond Organ in 1959.

And Accu-Bell Sound Inc. continues to develop and research to produce the best reverberation which are analog spring reverb and Digital reverb.