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diff --git a/desiredata/doc/3.audio.examples/H06.envelope.follower.pd b/desiredata/doc/3.audio.examples/H06.envelope.follower.pd
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+#N canvas 87 74 585 621 12;
+#X floatatom 354 464 4 0 0 0 - - -;
+#X floatatom 150 316 3 0 999 0 - #0-osc2 -;
+#X obj 150 336 osc~;
+#X text 162 12 ENVELOPE FOLLOWER;
+#X text 22 33 An envelope follower measures the mean square power of
+an signal as it changes over time. (You can convert mean square power
+to RMS ampitude or to decibels if you wish.) The term "mean square"
+means simply that the signal should be squared \, and then averaged.
+The averageing is done using a low-pass filter such as lop~.;
+#X obj 62 466 lop~;
+#X floatatom 93 444 3 0 100 0 - #0-lop -;
+#X obj 61 356 +~;
+#X text 187 317 <-- frequency of second oscillator;
+#X obj 62 330 osc~ 500;
+#X obj 62 413 *~;
+#X obj 62 522 snapshot~;
+#X floatatom 62 573 5 0 999 0 - - -;
+#X obj 62 545 sqrt;
+#X text 335 361 built-in envelope;
+#X obj 354 491 dbtorms;
+#X floatatom 354 518 5 0 999 0 - - -;
+#N canvas 536 459 382 265 startup 0;
+#X obj 22 24 loadbang;
+#X obj 22 48 bng 15 250 50 0 empty empty empty 0 -6 0 8 -262144 -1
+-1;
+#X obj 22 67 f \$0;
+#X text 35 195 This subpatch loads initial;
+#X text 31 219 values in number boxes.;
+#X msg 22 91 \; \$1-osc2 400 \; \$1-lop 10 \; \$1-metro 1 \; pd dsp
+1;
+#X obj 223 132 metro 250;
+#X obj 223 107 r \$0-metro;
+#X obj 223 156 s \$0-tick;
+#X connect 0 0 1 0;
+#X connect 1 0 2 0;
+#X connect 2 0 5 0;
+#X connect 6 0 8 0;
+#X connect 7 0 6 0;
+#X restore 217 598 pd startup;
+#X text 115 414 square the signal;
+#X text 124 440 <-- responsiveness;
+#X text 159 501 take snapshot;
+#X text 108 548 convert to RMS;
+#X text 327 599 updated for Pd version 0.39;
+#X text 334 381 follower for comparison;
+#X text 107 466 low-pass filter;
+#X text 114 573 output;
+#X obj 70 497 r \$0-tick;
+#X text 159 517 every 1/4 second;
+#X obj 389 439 r \$0-tick;
+#X obj 354 439 f;
+#X obj 376 414 env~;
+#X text 20 242 The env~ object at right \, which is a built-in envelope
+follower using a higher-quality low-pass filter than lop~ \, is shown
+for comparison. Its output is artificially slowed down to match the
+homemade one at left.;
+#X obj 150 359 *~;
+#X obj 185 360 tgl 15 0 empty empty empty 0 -6 0 8 -262144 -1 -1 0
+1;
+#X text 204 358 <-- on/off;
+#X text 20 128 Here we're adding two oscillators so the result should
+be an RMS of one if the second oscillator is on \, 0.707 otherwise.
+Note two effects: first \, the more responsive the envelope follower
+\, the less accurate the result (but the faster it responds). Second
+\, if the two oscillators are tuned close to each other their beating
+affects the nombers coming out.;
+#X connect 0 0 15 0;
+#X connect 1 0 2 0;
+#X connect 2 0 32 0;
+#X connect 5 0 11 0;
+#X connect 6 0 5 1;
+#X connect 7 0 10 0;
+#X connect 7 0 10 1;
+#X connect 7 0 30 0;
+#X connect 9 0 7 0;
+#X connect 10 0 5 0;
+#X connect 11 0 13 0;
+#X connect 13 0 12 0;
+#X connect 15 0 16 0;
+#X connect 26 0 11 0;
+#X connect 28 0 29 0;
+#X connect 29 0 0 0;
+#X connect 30 0 29 1;
+#X connect 32 0 7 1;
+#X connect 33 0 32 1;