Good alternative for a TL072?

[DIY_Guy]

I've recently built an effects loop based around the TL072 since I have a few laying around, but I'm looking for an option that's lower noise. I like the TL072 since it can handle a bit higher input voltage before clipping (4v I think on the + and -), and it seems like most suitable replacements only like 2 to 3 volts.

I was leaning towards the LM833 or NE5532, does anyone have any recommendations for one or the other? Or do you recommend something different? I'm looking to keep the price less than $1.50 a piece.

Thanks!

[Hardtailed]

I'm a big fan of Burr-Brown stuff. I use the OPA2604 (or is it 2640?) in all my TS style pedals. But they are more than 1.50$ a piece.

Is this for a tube amp? If so, I'd suggest looking into MOSFETs, they can run on the same high voltage as the tubes, making them really hard to clip. I have a MOSFET loop in my amp running on 300V and it's pretty much impossible to hear the difference when I hard-switch it out of the circuit (not my design though). Only 2 of them are required (buffer and recovery) and they're pretty cheap.

Beside that, there is not much help I can provide. I personally hate the TL072, but I'm not using enough opamps to consider a 2.50$ Burr-Brown piece a luxury.

[R.G.]

A lot of how big a signal it can handle depends on the size of the power supply.

The linear range of the inputs is generally a volt or two lower than the highest power supply voltage and a volt or two higher than the lowest power supply voltage. This is true for most general purpose opamps. However, the TL072 and most other general purpose opamps can take +/-15V to +/-18V power supplies, so this makes the input range as big as +/-7V (14V total). That's a lot of signal. The only way you get bigger than that is with rail-ro-rail input opamps, and those give you the extra few volts to the power supply, so with +/- 18V power you'd get +/- 9V peak inputs.

That's on the inputs. The outputs of opamps can't go beyond the power supplies either, and most general purpose amps only go to within a volt or two of the power supplies, similar to the inputs. There are rail-to-rail input and output opamps, but they tend to be expensive and also have lower maximum power supplies.

The TL072 is pretty darn quiet unless you have a bad one or a circuit which lets it amplify circuit noise. The LM833 is quieter, as is the NE5532. The NE5532 has a much lower input impedance that is generally known, about 100K. That may not matter. The difference from the jellybean TL072 to the 833 or 5532 is not huge, and may not be audible depending on how well the circuit is set up to be low noise.

That last is a caution for even the super-duper opamps. Spending $10-$20 for a low noise high voltage opamp won't help if the circuit setup has hum and noise on its own.

[DIY_Guy]

Yep it's in a tube amp. The loop works as is, but I can 'hear' the loop when it's on, no doubt. So that's why I was looking in to trying others. I think I'll end up just getting a few different Opamps and try them all out, and see what I like best.

Yeah $2.50 isn't out of my price range, since it's only going to be in a few amps, so I'll check out the Burr-Brown also.

[DIY_Guy]

Thanks for the info R.G.

[BackwardsBoB]

National came out with the LM4562 not too long ago. TI/Burr Brown has now responded with the OPA1612. Both are available in DIP packaging.

[Hardtailed]

Just wanted to add, yes I did say I like the OPA stuff in my Tubescreamer style pedals, yes I like the way they overdrive, but mostly I like them when used as clean boost, they have a certain clarity that the TL072 doesn't have. The TL sounds constricted to me.
I'm just extrapolating here to figure how they'd sound for a loop, but I'm sure it'd be nice!

[DIY_Guy]

Just wanted to add, yes I did say I like the OPA stuff in my Tubescreamer style pedals, yes I like the way they overdrive, but mostly I like them when used as clean boost, they have a certain clarity that the TL072 doesn't have. The TL sounds constricted to me.
I'm just extrapolating here to figure how they'd sound for a loop, but I'm sure it'd be nice!

What you say about the TL072 is exactly why I started this thread. Kinda sounds the same as when you bypass a cheap buffered stomp box. Really closes the high end for some reason.

I ordered about 5 different opamps a few minutes ago from Mouser to try out. So I went over my budget a bit, but now I can experiment and find something that I can stick with.

[dan stanton]

Try the TL081/082.

[booj]

I tried an OPA2132 to replace a TL072 in my homade dist. box, only to find they draw twice the current of a TL072. They did sound a bit better, but I opted for longer battery life.

[Hardtailed]

I tried an OPA2132 to replace a TL072 in my homade dist. box, only to find they draw twice the current of a TL072. They did sound a bit better, but I opted for longer battery life.

Oh yes, true, power consumption is also a factor why the TL072 is still so popular.

I don't believe this would be a problem in an mains powered amp though.

PS: I used to own a Mesa Triaxis. Every time I used it, I cursed Randall Smith for using TL072s to run its "dynamic drive" circuit (emulation of the graphic EQ on the Mark serie, which actually runs on high-voltage discrete components, no opamps there). It actually had a warning in the manual not to set your patch levels too high as it would overdrive the Dynamic Drive cricuit in a nasty way. As soon as you tried to get some interesting scooping out of it (I did play metal sometimes...), your 2K$ tube preamplifier turning into a 50$ Boss Metal Zone. I've been hating the TL072 ever since, but mostly Randall Smith hahaha
I ended up returning the Triaxis and bought the real thing instead, a Mark IV head, the graphic EQ was amazing!

[Steve Conner]

We all hate Randall Smith, lol

The MC33078 is a nice bipolar op-amp, like a super NE5532, not too expensive. I've used the MC33179, the quad low-power version, in EQ circuits where the TL074 was too noisy.

You have to choose between bipolar and JFET input op-amps. Bipolar work best in low-impedance circuits, JFET work best in high impedance circuits.

[octal]

I'm too lazy to look up the specs, but I think the LF353 was similar to the TLO72 and perhaps a tad quieter. Just a thought.

Nathan

[markbr]

TL072's can take a maximum +18V to +Vcc (pin8) and -18V (pin4) to -Vcc at the same time. So that's 36V in total. Am i right?

[markbr]

Oh yes, true, power consumption is also a factor why the TL072 is still so popular.

Hardtailed, do you know what current the TL072 draws?