diff --git a/dynamics/pump.h b/dynamics/pump.h
new file mode 100644
index 0000000..8574b17
--- /dev/null
+++ b/dynamics/pump.h
@@ -0,0 +1,144 @@
+#pragma once
+
+namespace trnr {
+template <typename sample>
+class pump {
+public:
+	pump()
+		: attack_ms(10.f)
+		, release_ms(100.f)
+		, hp_filter(80.0f)
+		, threshold_db(0.f)
+		, ratio(1000.0f)
+		, filter_frq(40000.f)
+		, filter_exp(0.f)
+		, treble_boost(0.f)
+	{
+		set_samplerate(44100);
+	}
+
+	void set_samplerate(double _samplerate)
+	{
+		samplerate = _samplerate;
+		set_attack(attack_ms);
+		set_release(release_ms);
+	}
+
+	void set_ratio(float value) { ratio = value; }
+
+	/* set threshold in db */
+	void set_threshold(float value) { threshold_db = value; }
+
+	/* set attack in ms */
+	void set_attack(float value)
+	{
+		attack_ms = value;
+		attack_coef = exp(-1000.0 / (attack_ms * samplerate));
+	}
+
+	/* set release in ms */
+	void set_release(float value)
+	{
+		release_ms = value;
+		release_coef = exp(-1000.0 / (release_ms * samplerate));
+	}
+
+	/* lowpass filter frequency in hz */
+	void set_filter_frq(float value) { filter_frq = value; }
+
+	/* accentuates the filter pumping effect */
+	void set_filter_exp(float value) { filter_exp = value; }
+
+	void process_block(sample** audio, sample** sidechain, uint frames)
+	{
+		// highpass filter coefficients
+		float hp_x = std::exp(-2.0 * M_PI * hp_filter / samplerate);
+		float hp_a0 = 1.0 - hp_x;
+		float hp_b1 = -hp_x;
+
+		// top end boost filter coefficients
+		float bst_x = exp(-2.0 * M_PI * 5000.0 / samplerate);
+		float bst_a0 = 1.0 - bst_x;
+		float bst_b1 = -bst_x;
+
+		for (uint i = 0; i < frames; i++) {
+
+			sample input_l = audio[0][i];
+			sample input_r = audio[1][i];
+
+			sample sidechain_in = (sidechain[0][i] + sidechain[1][i]) / 2.0;
+
+			// highpass filter sidechain signal
+			filtered = hp_a0 * sidechain_in - hp_b1 * filtered;
+			sidechain_in = sidechain_in - filtered;
+
+			// rectify sidechain input for envelope following
+			float link = std::fabs(sidechain_in);
+			float linked_db = trnr::lin_2_db(link);
+
+			// cut envelope below threshold
+			float overshoot_db = linked_db - (threshold_db - 10.0);
+			if (overshoot_db < 0.0) overshoot_db = 0.0;
+
+			// process envelope
+			if (overshoot_db > envelope_db) {
+				envelope_db = overshoot_db + attack_coef * (envelope_db - overshoot_db);
+			} else {
+				envelope_db = overshoot_db + release_coef * (envelope_db - overshoot_db);
+			}
+
+			float slope = 1.f / ratio;
+
+			// transfer function
+			float gain_reduction_db = envelope_db * (slope - 1.0);
+			float gain_reduction_lin = trnr::db_2_lin(gain_reduction_db);
+
+			// compress left and right signals
+			sample output_l = input_l * gain_reduction_lin;
+			sample output_r = input_r * gain_reduction_lin;
+
+			if (filter_exp > 0.f) {
+				// one pole lowpass filter with envelope applied to frequency for pumping effect
+				float freq = filter_frq * pow(gain_reduction_lin, filter_exp);
+				float lp_x = exp(-2.0 * M_PI * freq / samplerate);
+				float lp_a0 = 1.0 - lp_x;
+				float lp_b1 = -lp_x;
+				filtered_l = lp_a0 * output_l - lp_b1 * filtered_l;
+				filtered_r = lp_a0 * output_r - lp_b1 * filtered_r;
+			}
+
+			// top end boost
+			boosted_l = bst_a0 * filtered_l - bst_b1 * boosted_l;
+			boosted_r = bst_a0 * filtered_r - bst_b1 * boosted_r;
+			output_l = filtered_l + (filtered_l - boosted_l) * treble_boost;
+			output_r = filtered_r + (filtered_r - boosted_r) * treble_boost;
+
+			// calculate makeup gain
+			float makeup_lin = trnr::db_2_lin(-threshold_db / 5.f);
+
+			audio[0][i] = input_l * gain_reduction_lin * makeup_lin;
+			audio[1][i] = input_r * gain_reduction_lin * makeup_lin;
+		}
+	}
+
+private:
+	double samplerate;
+	float threshold_db = 0.f;
+	float attack_ms;
+	float release_ms;
+	float hp_filter;
+	float ratio;
+	float filter_frq;
+	float filter_exp;
+	float treble_boost;
+
+	sample filtered;
+	sample filtered_l = 0;
+	sample filtered_r = 0;
+	sample boosted_l = 0;
+	sample boosted_r = 0;
+	float attack_coef;
+	float release_coef;
+	float envelope_db = 0;
+};
+} // namespace trnr
\ No newline at end of file