### CHAPTER ONE

### THE RHODES TONE SOURCE

The unique tone of your RHODES Piano derives from the principle of the tuning fork. While the common tuning fork has two legs of equal length and mass, the tuning forks in your RHODES Piano differ from these in one very important way (Figure 1-1). The two prongs of our tuning fork are not of the same mass, shape or size. They are alike only in pitch. The lower, more resilient leg (Tine) responds visibly to the blow of a Hammer by vibrating in a wide arc at a certain frequency.

Figure 1-1. Tuning Fork Comparison

The upper leg (Tone Bar), while not so visible, does vibrate at the same frequency. The importance of this upper leg can easily be demonstrated by the following simple experiments.

1. Strike any note, preferably in the mid-range of the Piano. With the Sustain Pedal down, squeeze the upper leg with the fingers. The tone will die immediately.
2. Perform the same experiment, but this time touch the upper leg very lightly. The vibration will be distinctly felt under the fingers.

This patented concept of the tuning fork offers many advantages (Figure 1-2). One of these is that the upper leg (Tone Bar) supports some pitch variation in the lower leg (Tine). In other words, assuming G to be the target pitch, the lower leg could be deliberately tuned to F, F#, G, G# or A without any appreciable loss of support from the upper leg. This opens up a world of possibilities, as will be shown.

Figure 1-2. RHODES Tuning Fork

You will note a small coil Spring on the lower leg so designed as to be a tight fit. This coil Spring acts as a counter-weight and, therefore, as a pitch control. Moving this Spring will result in a change of pitch. By this means, then, it is possible to arrive at a fine tuning merely by sliding the Spring to the desired spot on the Tine. See Tuning Your RHODES Piano, Page 5-1.

The Tines in your RHODES Piano, like the strings of a guitar, are subject to breakage under stress. We here at the factory are constantly on the alert for ways to achieve the longest possible life in these as well as in all other component parts of your Piano. In actual tests, Tines picked at random have withstood in excess of 6,000,000 blows in a test machine. This machine is so constructed as to simulate actual playing conditions. Despite this, steel wire of even the finest quality, invariably has flaws along its surface. If these microscopically small flaws occur in a node point, they can become the point of eventual fracture. This is offered to explain the fact that, while one person's Piano may play for many years under constant use with no more than a couple or three broken Tines, another musician may experience a similar breakage within a shorter period of time.

For reasons just described, the Tines cannot be covered in the general warranty of the Piano.

In anticipation of this, we have devised a simple procedure for replacement - one which the musician can perform in about the time it takes to replace a guitar string. Refer to Tone Generator Assembly Replacement Procedure, Page 6-1.

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