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Jim Williams · 22nd May 2009

072's are problematic for me in EQ's. There is too much noise to use them for HF boost. They have only 40 db open loop gain at 10k hz, add + 15 db of HF boost and that opamp has 25 db of loop gain left to push down distortion. That creates high THD.

Better choices (if housecleaning work like phase compensation and power supply decoupling is done) are the National LME49720NA or the Analog Devices AD8599, the LT1358, the OP-275, the BB OPA2134, AD8512, etc.

Some of those have 80 db open loop gain at 10k hz, 40 db less dirt. Compare the AD8599 .9 nv/hz/sq noise to the 072's 22 nv noise.

Jim Williams
Audio Upgrades

22nd May 2009	#6
Jim Williams Voiding warranties Joined: Feb 2004 Location: beautiful Carlsbad, CA Posts: 10,051	072's are problematic for me in EQ's. There is too much noise to use them for HF boost. They have only 40 db open loop gain at 10k hz, add + 15 db of HF boost and that opamp has 25 db of loop gain left to push down distortion. That creates high THD. Better choices (if housecleaning work like phase compensation and power supply decoupling is done) are the National LME49720NA or the Analog Devices AD8599, the LT1358, the OP-275, the BB OPA2134, AD8512, etc. Some of those have 80 db open loop gain at 10k hz, 40 db less dirt. Compare the AD8599 .9 nv/hz/sq noise to the 072's 22 nv noise. Jim Williams Audio Upgrades