diff --git a/plug-ins/clicktrack.ny b/plug-ins/clicktrack.ny
index 79a6b2420..aea26c3c7 100644
--- a/plug-ins/clicktrack.ny
+++ b/plug-ins/clicktrack.ny
@@ -1,8 +1,9 @@
 ;nyquist plug-in
-;version 3
+;version 4
 ;type generate
 ;categories "http://lv2plug.in/ns/lv2core#GeneratorPlugin"
 ;name "Click Track..."
+;preview linear
 ;action "Generating Click Track..."
 ;info "For help, select one of two help screens in 'Action choice' below."
 ;author "Dominic Mazzoni"
@@ -13,8 +14,8 @@
 ;; http://www.gnu.org/licenses/old-licenses/gpl-2.0.html .
 ;; original clicktrack.ny by Dominic Mazzoni,
 ;; modified by David R. Sky and Steve Daulton.
-;; Minimum Audacity version: 1.3.4
 ;;
+;; Updated to v4 by Steve Daulton May 2015
 ;; bug fixes and restructured by Steve Daulton Sept 2011.
 ;; string input verification added by Steve Daulton, 2009.
 ;; added click pitch [user request] and sound types fields September 2007 (D.R.Sky).
@@ -286,6 +287,12 @@ Use whole numbers only.~%"))))
         (if m-s (setq measures 
           (/ (m-s-to-seconds m-s)(* sig beatlen))))
 
+        ;if previewing, restrict number of measures
+        (let ((preview (/ (get '*project* 'preview-duration)
+                          (* sig beatlen)))) 
+          (if (not (get '*track* 'view))  ;NIL if preview
+              (setq measures (min preview measures))))
+
         ;round up number of measures
         (setq measures (round-up measures))
 
diff --git a/plug-ins/pluck.ny b/plug-ins/pluck.ny
index 120b87cf5..eb52daab7 100644
--- a/plug-ins/pluck.ny
+++ b/plug-ins/pluck.ny
@@ -1,8 +1,9 @@
 ;nyquist plug-in
-;version 3
+;version 4
 ;type generate
 ;categories "http://lv2plug.in/ns/lv2core#GeneratorPlugin"
 ;name "Pluck..."
+;preview linear
 ;action "Generating pluck sound..."
 ;info "MIDI values for C notes: 36, 48, 60 [middle C], 72, 84, 96."
 ;author "David R.Sky"
@@ -11,7 +12,7 @@
 ;; Released under terms of the GNU General Public License version 2:
 ;; http://www.gnu.org/licenses/old-licenses/gpl-2.0.html .
 
-;control p "Pluck MIDI pitch" int "" 60 1 127
+;control pitch "Pluck MIDI pitch" int "" 60 1 120
 ;control fade "Fade-out type" choice "abrupt,gradual" 0
 ;control dur "Duration [seconds]" real "" 1 0.1 30
 
@@ -24,12 +25,24 @@
 ; maximum amplitude. As defined in Audacity, 'pluck' has 
 ; incorrect length duration and clipping at the start which gives
 ; rise to DC offset. Using 'snd-pluck' avoids the clipping and 
-; offset so we don't need the highpass8 filter that we used before.  
+; reduces offset so we don't need the highpass8 filter that we used before.
+; Updated to v4 by Steve Daulton May 2015
 
 
 ; set final-amp for abrupt or gradual fade
 (setf final-amp (if (= fade 1) 0.001 0.000001))
 
-(let* ((pluck-sound (snd-pluck *sound-srate* (step-to-hz p) 0 dur final-amp))
+;; Get length of preview
+(setq pdur
+  (if (get '*track* 'view) ;NIL if preview
+      dur
+      (get '*project* 'preview-duration)))
+
+(let* ((pluck-sound (snd-pluck *sound-srate* (step-to-hz pitch) 0 dur final-amp))
+       (pluck-sound (extract-abs 0 pdur pluck-sound)) ; shorten if necessary for preview.
        (max-peak (peak pluck-sound ny:all)))
-  (scale (/ 0.8 max-peak) pluck-sound))  
+  ;; snd-pluck has a random element and will occasionally produce
+  ;; zero amplitude at very high pitch settings. Avoid division by zero.
+  (if (> max-peak 0)
+      (scale (/ 0.8 max-peak) pluck-sound)
+      pluck-sound))
diff --git a/plug-ins/rissetdrum.ny b/plug-ins/rissetdrum.ny
index 959839e58..32cfd1f74 100644
--- a/plug-ins/rissetdrum.ny
+++ b/plug-ins/rissetdrum.ny
@@ -1,14 +1,15 @@
 ;nyquist plug-in
-;version 3
+;version 4
 ;type generate
 ;categories "http://lv2plug.in/ns/lv2core#GeneratorPlugin"
+;preview linear
 ;name "Risset Drum..."
 ;action "Generating Risset Drum..."
 ;author "Steven Jones"
 ;copyright "Released under terms of the GNU General Public License version 2"
 
 ;; rissetdrum.ny by Steven Jones, after Jean Claude Risset.
-;; Updated by Steve Daulton July 2012.
+;; Updated by Steve Daulton July 2012 and May 2015.
 ;; Released under terms of the GNU General Public License version 2:
 ;; http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 ;;
@@ -16,7 +17,7 @@
 ;; http://wiki.audacityteam.org/wiki/Nyquist_Plug-ins_Reference
 
 ;control freq "Frequency (Hz)" real "" 100 50 2000
-;control decay "Decay (seconds)" real "" 2 0.125 10
+;control decay "Decay (seconds)" real "" 2 0.1 60
 ;control cf "Center frequency of noise (Hz)" real "" 500 100 5000
 ;control bw "Width of noise band (Hz)" real "" 400 10 1000
 ;control noise "Amount of noise in mix (percent)" real "" 25 0 100
@@ -26,6 +27,8 @@
 (defun sanitise (val minx maxx)
   (min (max val minx) maxx))
 
+;; Not required with validation in Audacity 2.1.1 but left
+;; for compatibility.
 (setq freq (sanitise freq 1 (/ *sound-srate* 2)))
 (setq decay (sanitise decay 0.1 600))
 (setq cf (sanitise cf 1 (/ *sound-srate* 2)))
@@ -33,6 +36,12 @@
 (setq noise (sanitise (/ noise 100) 0 1))
 (setq gain (sanitise gain 0 1))
 
+;; Get length of preview
+(setq pdur
+  (if (get '*track* 'view) ;NIL if preview
+      decay
+      (get '*project* 'preview-duration)))
+
 (setq *rdrum-table* 
   (list 
     (mult 0.17
@@ -73,5 +82,6 @@
 
 ;; Generate and normalize
 (let* ((output (risset-drum freq decay cf bw noise))
+       (output (extract-abs 0 pdur output)) ; shorten if necessary for preview.
        (peakval (peak output ny:all)))
   (scale (/ gain peakval) output))