replace in opening quotations

node28.html

@@ -72,12 +72,12 @@ Sampling
 </H1>
 
 <P>
-``Sampling"
+"Sampling"
 <A NAME="2203"></A>
 is nothing more than recording a live signal into a wavetable, and then later
 playing it out again.  (In commercial samplers the entire wavetable is
-usually called a ``sample" but to avoid confusion we'll only use the word
-``sample" here to mean a single number in an audio signal.) 
+usually called a "sample" but to avoid confusion we'll only use the word
+"sample" here to mean a single number in an audio signal.) 
 
 <P>
 At its simplest, a sampler is simply a wavetable oscillator, as was shown in
@@ -281,7 +281,7 @@ h[n] = 12 {{\log_2} \left \vert y[n] - y[n-1] \right \vert}
 </DIV>
 <BR CLEAR="ALL">
 <P></P>
-(Here the enclosing bars ``<IMG
+(Here the enclosing bars "<IMG
  WIDTH="7" HEIGHT="32" ALIGN="MIDDLE" BORDER="0"
  SRC="img202.png"
  ALT="$\vert$">" mean absolute value.)  
@@ -361,7 +361,7 @@ at the beginning of each new cycle.
 
 <P>
 It's well known that transposing a recording also transposes its timbre--this
-is the ``chipmunk" effect.  Not only are any periodicities (such as might
+is the "chipmunk" effect.  Not only are any periodicities (such as might
 give rise to pitch) transposed, but so are the frequencies of
 the overtones.  Some timbres, notably those of vocal sounds, have characteristic
 frequency ranges in which overtones are stronger than other nearby ones.
@@ -378,7 +378,7 @@ wavetables periodically.  In Section <A HREF="node27.html#sect2.oscillator">2.1<
 repeated quickly enough that the repetition gives rise to a pitch, say between
 30 and 4000 times per second, roughly the range of a piano.  In the current 
 section we assumed a wavetable one second long, and in this case
-``reasonable" transposition factors (less than four octaves up) would give rise
+"reasonable" transposition factors (less than four octaves up) would give rise
 to a rate of repetition below 30, usually much lower, and going down as low as
 we wish.
 
@@ -506,7 +506,7 @@ location as the segment's midpoint, we first subtract <IMG
 <CAPTION ALIGN="BOTTOM"><STRONG>Figure 2.5:</STRONG>
 A simple looping sampler, as yet with no amplitude control.  
 There are inputs to control the frequency and the segment size and location.
-The ``-" operation is included if we wish the segment location to be specified
+The "-" operation is included if we wish the segment location to be specified
 as the segment's midpoint; otherwise we specify the location of the left
  end of the segment.</CAPTION>
 <TR><TD><IMG