diff --git a/src/nodes.jl b/src/nodes.jl
index e640a00..f4f5002 100644
--- a/src/nodes.jl
+++ b/src/nodes.jl
@@ -54,15 +54,21 @@ end
 
 function render(node::SinOscRenderer{AudioNode}, device_input::AudioBuf,
         info::DeviceInfo)
-    freq = render(node.freq, device_input, info)
+    freq = render(node.freq, device_input, info)::AudioBuf
     block_size = min(length(freq), info.buf_size)
-    outbuf = Array(AudioSample, block_size)
+    if(length(node.buf) != block_size)
+        resize!(node.buf, block_size)
+    end
+    outbuf = node.buf
 
-    phase = node.phase
-    dt = 1/(info.sample_rate)
-    for i in 1:block_size
+    phase::Float32 = node.phase
+    pi2::Float32 = 2pi
+    phase_step::Float32 = 2pi/(info.sample_rate)
+    i::Int = 1
+    while i <= block_size
         outbuf[i] = sin(phase)
-        phase += 2pi*dt*freq[i]
+        phase = (phase + phase_step*freq[i]) % pi2
+        i += 1
     end
     node.phase = phase
     return outbuf
diff --git a/test/test_nodes.jl b/test/test_nodes.jl
index 4697d95..9b6a1dc 100644
--- a/test/test_nodes.jl
+++ b/test/test_nodes.jl
@@ -55,7 +55,7 @@ render_output = render(mix, dev_input, test_info)
 @test render_output == AudioSample[]
 
 # TODO: I think we can do better than this
-const FLOAT_THRESH = 1e-9
+const MSE_THRESH = 1e-7
 
 info("Testing SinOSC...")
 freq = 440
@@ -64,34 +64,36 @@ t = linspace(0, 1, test_info.sample_rate+1)
 test_vect = convert(AudioBuf, sin(2pi * t * freq))
 osc = SinOsc(freq)
 render_output = render(osc, dev_input, test_info)
-@test mse(render_output, test_vect[1:test_info.buf_size]) < FLOAT_THRESH
+@test mse(render_output, test_vect[1:test_info.buf_size]) < MSE_THRESH
 render_output = render(osc, dev_input, test_info)
 @test mse(render_output,
-        test_vect[test_info.buf_size+1:2*test_info.buf_size]) < FLOAT_THRESH
+        test_vect[test_info.buf_size+1:2*test_info.buf_size]) < MSE_THRESH
 @test 200 > (@allocated render(osc, dev_input, test_info))
 stop(osc)
 render_output = render(osc, dev_input, test_info)
 @test render_output == AudioSample[]
 
-#info("Testing SinOsc with signal input")
-#t = linspace(0, 1, test_info.sample_rate+1)
-#f = 440 .- t .* (440-110)
-#dt = 1 / test_info.sample_rate
-## NOTE - this treats the phase as constant at each sample, which isn't strictly
-## true. Unfortunately doing this correctly requires knowing more about the
-## modulating signal and doing the real integral
-#phase = cumsum(2pi * dt .* f)
-#unshift!(phase, 0)
-#expected = convert(AudioBuf, sin(phase))
-#
-#freq = LinRamp(440, 110, 1)
-#osc = SinOsc(freq)
-#render_output = render(osc, dev_input, test_info)
-#@test mse(render_output, expected[1:test_info.buf_size]) < FLOAT_THRESH
-#render_output = render(osc, dev_input, test_info)
-#@test mse(render_output,
-#        expected[test_info.buf_size+1:2*test_info.buf_size]) < FLOAT_THRESH
-##@test 400 > (@allocated render(osc, dev_input, test_info))
+info("Testing SinOsc with signal input")
+t = linspace(0, 1, test_info.sample_rate+1)
+f = 440 .- t .* (440-110)
+dt = 1 / test_info.sample_rate
+# NOTE - this treats the phase as constant at each sample, which isn't strictly
+# true. Unfortunately doing this correctly requires knowing more about the
+# modulating signal and doing the real integral
+phase = cumsum(2pi * dt .* f)
+unshift!(phase, 0)
+expected = convert(AudioBuf, sin(phase))
+
+freq = LinRamp(440, 110, 1)
+osc = SinOsc(freq)
+render_output = render(osc, dev_input, test_info)
+@test mse(render_output, expected[1:test_info.buf_size]) < MSE_THRESH
+render_output = render(osc, dev_input, test_info)
+@test mse(render_output,
+        expected[test_info.buf_size+1:2*test_info.buf_size]) < MSE_THRESH
+# give a bigger budget here because we're rendering 2 nodes
+println("alloc: ", @allocated render(osc, dev_input, test_info))
+@test 500 > (@allocated render(osc, dev_input, test_info))
 
 info("Testing ArrayPlayer...")
 v = rand(AudioSample, 44100)
@@ -121,8 +123,8 @@ info("Testing LinRamp...")
 ramp = LinRamp(0.25, 0.80, 1)
 expected = convert(AudioBuf, linspace(0.25, 0.80, test_info.sample_rate+1))
 render_output = render(ramp, dev_input, test_info)
-@test mse(render_output, expected[1:test_info.buf_size]) < FLOAT_THRESH
+@test mse(render_output, expected[1:test_info.buf_size]) < MSE_THRESH
 render_output = render(ramp, dev_input, test_info)
 @test mse(render_output,
-        expected[(test_info.buf_size+1):(2*test_info.buf_size)]) < FLOAT_THRESH
+        expected[(test_info.buf_size+1):(2*test_info.buf_size)]) < MSE_THRESH
 @test 300 > (@allocated render(ramp, dev_input, test_info))