Substitute OPA637 for TL072??

[Tweedtone]

I have BK Butler Tube Driver with a TL072 in it. It's a little dark sounding and I'd like to try other opamps so I picked up a OPA637, AD8066 and a AD8620 all of which I think are direct replacements.

Luckily the TL072 is on a socket. I swapped in the OPA637 but when I hit the switch it doesn't work. Pulled it and no bent pins, looks fine. Went back to the TL072 and it works. Ok, maybe it's a bad chip. Got it from Digi-key so it should be alright but who knows.

I put the AD8066 on a Brown Dog adapter, plugged it in and same as the OPA637.

what am I missing here?

Thanks

[davidsrsb]

TL072 is a dual
OPA637 is a single, decompensated for gain >5

[Tweedtone]

Ah, right.
The TL072 sounds veiled, lacks clearity to me so what would be a good sub.

[Amplifier tube]

Alternative can be used OPA2604

[jean-paul]

"Ah right". Trying to mix single and dual opamps indicates that you did not check any datasheet which implies you don't know what you are doing. This is not meant negatively but simply doing things to see what happens will cost you money, time and grief. Always check specifications before even thinking of swapping parts.

OPA2604 is better than TL072 and relatively cheap. It is a direct replacement but I would decouple the power pins for best results. OPA637 is much better but then you would have to use an adapter for 2 x single DIL to DIL8. So you would need 2 x OPA637.

But OPA637 can only be used if the amplification is more than 5 x. Otherwise its "unity gain stable" brother OPA627 should be used.

[Mr. Steve]

opa2134 or opa2132 way better than a tl072 and cheaper than a 637 / 627 and dual same pinout

[Mooly]

If you find the TLO72 "dark" try the LM4562 or even an NE5532 although it would help to see the circuit. I'm assuming any offsets (or lack of) due to the original being a DIFET device are of no concern here.

Just try them...

[nelsonvandal]

AD8620 and AD8066 are both dual opamps. OPA072 is good for 36V, AD8620 26V and AD8066 24V. What's the supply? OPA072 is slow, AD8620 is fast and AD8066 is very fast. It could be a "bad" circuit layout not suitable for fast opamps. Decoupling caps in close proximity to the opamp's power pins often solve this problem.

If you can get those Analog opamps to work in your circuit, you'll certainly wont find them veiled. They're on the harsh side, I think.

If it doesn't have to be a FET input opamp you should try LME49720 (=LM4562). I think it'll have the clarity you want.

[formula 22]

Hi all!
What can be substituted in this circuit for the OPA637?
Thanks

[Mooly]

The OPA134 should be be good as too the OPA604.

A TL071 will work although not optimal.

You have to stick with FET input device as the input is DC coupled and you want to ensure no bias current flows in the cartridge not to mention offset problems.