Hammond Basics: History and Mechanics








Hammond organs have such an iconic and important place in rock, blues, and soul music. In this three part series of interviews with Cliff Unruh, we are going to talk about inventor Laurens Hammond and how the Hammond Organ Company came about, how the Hammond works from a simplified technical standpoint, and how the mechanical design shapes the sound characteristics that make the Hammond so iconic.

A little background for our readers, Cliff Unruh is an internationally recognized authority on Hammond Organs. He is a keyboard player and music lover, and owns a reputable Hammond dealership, Hammond Central. I met Cliff through a referral from a technician at the Hammond factory. And after a mind blowing in depth conversation with Cliff who was able to answer all my Hammond questions and then some, I decided it would make a great series of articles to get Cliff on the line and do some recorded and transcribed interviews. So here we are now.

Cliff, let's start with the basics. Tell me about Laurens Hammond and how the Hammond Organ Company came about.

Laurens Hammond was an inventor, and made clocks. He and his clock company ran into some trouble with the bank, and trying to figure out how to salvage this company they thought, "Okay we can build synchronous motors, we have the ability to create gears, we have all this facility here, what else can we make?" And the idea came up to create an instrument.

In fact the original instrument was not going to be an organ it was going to be the equivalent of a modern day keyboard. His concept was a single manual instrument that would plug into a radio set for amplification. But what they ended up with was a two manual organ. The Hammond Model-A. He had to convince his board of directors to allow him to patent this in his own personal name rather than the name of the company because if he did the name of the company, the whole thing would be owned by the bank.

And so they trusted him. He put it in his name. And it took off. He bailed the company out of debt and the Hammond Clock Company ultimately became the Hammond Organ Company.

Now let's segue into the topic of how early Hammonds are engineered, because I know it's not simple. But let's help a layperson like myself understand better.

The interesting thing about the Hammond is that it has characteristics about it that are so unique to the methodology that was used in the creation of the sound, and are characteristic of the Hammond Organ exclusively.

Because the Hammond organ in its original form is not really an electronic instrument, it is electro mechanical instrument. It uses the AC synchronous motor to spin a series of gears, and tone wheels at different RPMs each field has a scalloped edge and a magnet and a coil and so each field is generating its own sine wave on a particular pitch and then the drop bars with the Hammond organ are used to mix those pitches on one key. So here you have nine draw bars. Well theoretically on a Hammond Organ you can play nine pitches on one key. And so if you play a triad, really theoretically with just playing a simple triad you can be playing 27 notes, 27 pitches.

Which is why the sound of the Hammond Organ is so unique and is very rich and it's full. For the uninitiated it's difficult to jam with a Hammond organ because sometimes it's difficult to tell what the actual tonic is because of the thick sound and all the harmonics that you can put into into the mix with the draw bars.

And then of course because it's a pre-amplified sound and you've got nine wire contacts on the back of the keys and they're touching the bus bar a ground and they make a little pop which Laurens Hammond thought was a horrible flaw.

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