Author Topic: No__105__Drawbars (xx) The simple way: Forget Numbers – Think Shapes!  (Read 47 times)

Peter Anderson

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Drawbars         Forget Numbers - Think Shapes!

The Hammond drawbar system, which we have on our Yamaha AR organs, is called the FLUTE/TIBEA (THEATRE) and is accessed for each of your Key/PedalBoards, via the UPPER ORGAN, LOWER ORGAN & PEDAL ORGAN tabs in the ENSEMBLE section.   I will continue to refer to them as DRAWBARS.

We could receive instruction for several months about the intricacies of different famous players’ settings, but finish up feeling that we know less about the subject than when we started.

So in this Pearl I want to share how simple it can be to translate the sound that’s in your head into a drawbar setting.

Here I am not taking the conventional approach, that you will find elsewhere on the AR Group website, referring to the science behind their use, and talk about church organ pipes and their lengths, etc., because I don't need to.  Here is a much more intuitive and simple way to get to grips with creating your desired drawbar sounds.

In essence, the drawbars can be thought of as an upside-down graphic equaliser, and that's exactly how imaginative players use them to create their individual tones.  You still have the bass on the left and the treble on the right, but because the bars are rolled out toward you, to increase their effect, or volume, the ‘EQ curves’ appear vertically flipped.  Provided you’ve used a graphic equaliser, and I imagine most of you have, you should be able to relate to the drawbars straight away.

We can get involved in all sorts of discussion about pipe lengths, fundamentals, octaves, etc., but broadly, the drawbars can be considered a set of 9 tone controls on the AR100, or 8 tone controls on the AR80, ranging from deep bass on the left to sparkling treble on the right.

Let’s assume that you have never used a graphic equaliser, and, therefore start with a much simpler view of the drawbar system.   
Let’s pretend the AR has just 3 drawbars:

                      a bass,
                      a middle, and
                      a treble control.

This is just like a basic hi-fi graphic equaliser, but in the form of pull-out bars rather than rotary knobs.

In the diagrams below I’ve shown a very simple 3 Drawbar arrangement with a
       Bass / Middle / Treble     setup.

Here is a bassy sound, which is created by rolling out the Bass bar to the maximum amount, and setting the middle and treble bars at much lower levels.   


While here the level of the Bass bar is much reduced, and the Treble bar is set to maximum to generate a trebly sound.


And, of course, this setup generates what we can call a middling sound.



If that makes sense, you now understand exactly how the original Hammond drawbars work and how to use your Yamaha AR Flute/Tibia lightbars. 

So in the next Reply, we see how we can easily add to this, to generate our own sounds.

Peter

Peter Anderson

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Now that you understand exactly how the Hammond principle of drawbars works, all you need to do is add extra frequency stages so that the level of control becomes much more extensive.  The diagram below shows the expanded version, as used on a real Hammond, or Yamaha AR, but with the 'footage' markings replaced by three general zones.
                      1   Bass on the left,
                      2   Middle in the middle, and
                      3   Treble on the right.

As with a graphic equaliser, adding more frequencies from the Bass (or the left) side of the range, whilst keeping the Treble components at reduced level creates a greater bassy sound, like this:


The lights that you illuminate will be very similar to this, and it is important to think of the general shape rather than precise settings.

Furthermore the Yamaha AR 80 has one of these lightbars missing, - 13/5, which sits between the 2 and the 11/3.

Equally, by adding more frequencies from the Treble (or the right) side whilst reducing the Bass region gives a more ‘trebly’ sound, like this:



Try to think of the drawbars as a complete unit rather than a series of individual components.
If you can do that, you’ve got the general idea of how to set your drawbars for the kind of sound you want.
Simply  think   bass,   middle,   treble,   and roll out the bars from the appropriate region of the sound spectrum.

For much of the time simply ignore the footage readings.  This is the intuitive way in which experienced Hammond players have understood and used their instruments for decades.   It’s not about saying: “I’m going to set this particular drawbar to this volume level.”    It is more about associating the whole set of bars with elements of the frequency range, then visualising, and setting up ‘tone shapes’.    By that I mean, the visual shapes created by the drawbar arrangements you choose.

Peter

Peter Anderson

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Bearing in mind that the drawbar system is vertically flipped in comparison to a graphic equaliser, those who have an affinity with graphic equalisers will recognise the left hand ‘tone shape’ shown below as giving a ‘scooped’ midrange with strong bass and treble elements. 


Conversely, the right hand ‘tone shape’ produces a nasal sound, which might in a graphic equaliser be used to simulate a human voice.    Even though this is an organ, the effect on the timbre is just the same, like this:
.

Drawbars, themselves are physically adding individual pitches to a composite tone, rather than merely emphasising or de-emphasising pitches, which are already there, as is the case with a graphic equaliser.    But there's very little difference in the way a given tone shape impacts on the tonal character - provided of course that you remember your drawbar tone shapes are upside down.  They're vertically mirrored images of your graphic equaliser tone shapes.

Of course, it’s worth investigating the exact settings that some famous Hammond players have used in their renditions, if you want to accurately copy them and learn more about special techniques.   You can read more about that in Peters Pearl #85 - Drawbars - (xviii) Some settings to try.

http://www.ar-group.org/smforum/index.php?topic=3029.0

Remember that on the Hammond organs the frequency bands, their second (5 1/3') and third (8') drawbars, are  reversed to those on our Yamaha AR organs.
On a graphic equaliser they would exactly match the Yamaha layout.
 
You can and should, of course, use your ears to make fine adjustments, but the important thing is that you have a ballpark vision of what is changing the sound.

The idea of imaginary Bass, Middle and Treble zones described above, gives you a structured and simple method, of generating the sound you are looking for.
It’s just like adjusting a graphic equaliser on a hi-fi, so if you're able to adjust your hi-fi to sound exactly as you want, there’s no reason why you can’t do the same with your Yamaha AR drawbars.

So in short, Forget Numbers – Think (and remember) Shapes!

In the next Reply, I show more shapes of drawbar settings.

Peter

Peter Anderson

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There are four basic families of organ tone, and in this and the following Replies, I'll show you the basic pattern of Drawbar settings to create each of them.


1       Diapason is defined as a typical organ sound.   
It is commonly used as a foundation setting, so it is often referred to by that name.

Start by setting your drawbars to resemble this shape: -



It has a strong fundamental and second harmonic, with weaker upper harmonics.     Also as an 8' combination, it makes an excellent accompanying sound.

However, with a 16' setting, it is the basis for a full theatre organ sound.

When some of the other family members (see the following Replies) are emphasized in the combinations, you may have a flute diapason, a reed diapason, or a string diapason.

I stated that this Pearl would contain no numbers, but if you want some examples of diapason drawbar settings for your AR, then click on the following link.

This link is also available in Ed’s Tickles, but you may like to check out this website, which graphically shows Hammond Drawbar settings for different sounds.

http://keyboardservice.com/Drawbars.asp

Remember that on the AR the 8’ and 5 1/3’ lightbars are reversed, and that you have 6 settings for each one where the Hammond lists 8.
If you are looking for a particular sound this is a first class resource.

So back to our subject, occasionally you’ll hear the terms open or stopped preceding the name of the designated family, with names like open diapason or stopped flute, for example.

These refer to open or closed (also known as stopped) organ pipes.   
 
When the upper end of a pipe is closed, the pipe produces a softer and somewhat different tone quality.   

Examples of the open and stopped drawbar settings can be found by clicking that link given above.

Peter