Since all this stuff is opinions anyway.... you should modify a pair of channels and run mixes you know through it. I believe each opamp will sound different depending on the circuit.

I only know the Burr Brown op amps, many people like Analog Devices opamps. Some say they are more aggressive. Be aware of different pinouts, which is why I went with Burr Brown.

For single opamps replacing TL071,TL2071, 5545 with OPA637,OPA627, OPA602, OPA604, OPA134 would be a good test. For Dual opamps like TL072, 5532, replace with OPA2604,OPA2134.

I like the OPA637,OPA627 and OPA2604.

Faster opamps can oscillate in some circuits, and can draw more current from the power supply. If yr changing hundreds of amps in a board this might be a consideration. I just went for it, but tested to make sure there was no distortion or squealing.

I started with the stereo buss. I installed OPA627 and was blown away by the difference. Much more 3D sounding. I then swapped these out with OPA637 and everything tightened up even more. Over the course of a year I've swapped every amp in the signal flow. Last night I replaced the TL071's with OPA2604 in the EQ section and my EQ no longer smears the signal. Before when I'd turn an EQ knob it didn't "feel good" now it "feels good" even on extreme settings.

My next project is to use different opamps on the groups for different flavors. I've also swapped out some opamps on my compressors and again a huge difference in sound. 5534 with OPA627.

Definitely do listening tests though. I have some channels in my board which are different circuits then other channels. These are not working so well with the faster opamps. They sound thin with some distortion. Tonight I'm going to switch those channels back to stock and switch one amp at a time.

meant 5534...not 5545. so I replaced the 5534s' wtih opa637 or opa627

I only know the Burr Brown op amps, many people like Analog Devices opamps. Some say they are more aggressive. Be aware of different pinouts, which is why I went with Burr Brown.

If you want to test different opamps, try Texas Instruments - they give out free samples. JRC might also.


Jeremy