diff --git a/scripts/_amp2.lua b/scripts/_amp2.lua
index 89d11fc0fd..5a594d57e3 100644
--- a/scripts/_amp2.lua
+++ b/scripts/_amp2.lua
@@ -41,7 +41,7 @@ function dsp_runmap (bufs, in_map, out_map, n_samples, offset)
 
 		local bi = bufs:get_audio(ib)
 		local bo = bufs:get_audio(ob)
-		assert (bi:sameinstance(bo))
+		assert (bi == bo)
 
 		local a = bufs:get_audio(ib):data(offset):array() -- get a reference (pointer to array)
 		for s = 1,n_samples do
diff --git a/scripts/_amp3.lua b/scripts/_amp3.lua
index bb1a589b27..006a22afbb 100644
--- a/scripts/_amp3.lua
+++ b/scripts/_amp3.lua
@@ -38,7 +38,7 @@ function dsp_run (ins, outs, n_samples)
 	local gain = ARDOUR.DSP.dB_to_coefficient (ctrl[1])
 	assert (#ins == #outs) -- ensure that we can run in-place (channel count matches)
 	for c = 1,#ins do
-		assert (ins[c]:sameinstance(outs[c])) -- check in-place
+		assert (ins[c] == outs[c]) -- check in-place
 		ARDOUR.DSP.apply_gain_to_buffer (ins[c], n_samples, gain); -- process in-place
 	end
 end
diff --git a/scripts/_biquad_filter.lua b/scripts/_biquad_filter.lua
index c0dec8bd1f..5dc6e3be1b 100644
--- a/scripts/_biquad_filter.lua
+++ b/scripts/_biquad_filter.lua
@@ -148,7 +148,7 @@ function dsp_run (ins, outs, n_samples)
 		for c = 1,#ins do
 			-- check if output and input buffers for this channel are identical
 			-- http://manual.ardour.org/lua-scripting/class_reference/#C:FloatArray
-			if ins[c]:sameinstance (outs[c]) then
+			if ins[c] == outs[c] then
 				filters[c]:run (ins[c]:offset (off), siz) -- in-place processing
 			else
 				-- http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR:DSP
diff --git a/scripts/_notch_bank.lua b/scripts/_notch_bank.lua
index 619541823d..cd1f71bdc6 100644
--- a/scripts/_notch_bank.lua
+++ b/scripts/_notch_bank.lua
@@ -109,7 +109,7 @@ function dsp_run (ins, outs, n_samples)
 	-- process all channels
 	for c = 1, chn do
 		-- when not processing in-place, copy the data from input to output first
-		if not ins[c]:sameinstance (outs[c]) then
+		if ins[c] ~= outs[c] then
 			ARDOUR.DSP.copy_vector (outs[c], ins[c], n_samples)
 		end
 
diff --git a/scripts/_pong.lua b/scripts/_pong.lua
index acf3c010c9..8eef49f004 100644
--- a/scripts/_pong.lua
+++ b/scripts/_pong.lua
@@ -138,7 +138,7 @@ function dsp_run (ins, outs, n_samples)
 	for c = 1,#outs do
 		-- check if output and input buffers for this channel are identical
 		-- http://manual.ardour.org/lua-scripting/class_reference/#C:FloatArray
-		if not ins[c]:sameinstance (outs[c]) then
+		if ins[c] ~= outs[c] then
 			-- fast (accelerated) copy
 			-- http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR:DSP
 			ARDOUR.DSP.copy_vector (outs[c], ins[c], n_samples)
diff --git a/scripts/_smash.lua b/scripts/_smash.lua
index cdb1938a26..2ebcac19aa 100644
--- a/scripts/_smash.lua
+++ b/scripts/_smash.lua
@@ -11,7 +11,7 @@ end
 function dsp_run (ins, outs, n_samples)
 	for c = 1, #outs do -- for each output channel (count from 1 to number of output channels)
 
-		if not ins[c]:sameinstance (outs[c]) then -- if processing is not in-place..
+		if ins[c] ~= outs[c] then -- if processing is not in-place..
 			ARDOUR.DSP.copy_vector (outs[c], ins[c], n_samples) -- ..copy data from input to output.
 		end
 
diff --git a/scripts/amp4.lua b/scripts/amp4.lua
index 6254082ad9..276b4a0af6 100644
--- a/scripts/amp4.lua
+++ b/scripts/amp4.lua
@@ -66,7 +66,7 @@ function dsp_run (ins, outs, n_samples)
 		for c = 1,#ins do -- process all channels
 			-- check if output and input buffers for this channel are identical
 			-- http://manual.ardour.org/lua-scripting/class_reference/#C:FloatArray
-			if not ins[c]:sameinstance (outs[c]) then
+			if ins[c] ~= outs[c] then
 				-- http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR:DSP
 				ARDOUR.DSP.copy_vector (outs[c]:offset (off), ins[c]:offset (off), siz)
 			end