 number range + 1. <code>nTable</code> is set
  to 136.</p>
  <dl>
  <dt>Cutoff</dt>
  <dd>
  <p>Changes filter cutoff frequency.</p>
  </dd>
  <dt>KeyFollow</dt>
  <dd>
  <p>When set to right-most, cutoff frequency is set to make the number
  of overtone to be almost same regardless of pitch of note. When set to
  left-most, it only use the value of <code>Cutoff</code>.</p>
  </dd>
  <dt>A, D, S, R, Amount</dt>
  <dd>
  <p>Filter envelope parameters. <code>Amount</code> changes the amount
  of modulation t