Dual op-amps... which is your favourite?

I’m shopping for op-amps for an audio application, there are so many out there (!) that claim low noise, high current. I’m after it in a DIP8 package by the way…

Am using the TI 1612, is the TI 1622 worth it?

What would you get?

3 Likes

I just always use the TL072 with no issues.
Pinout:
image

4 Likes

(nit: that pinout was last featured in the bad pinout subthread :smiley: - GND should be Vcc− i.e. negative supply)

2 Likes

oh yeah, my bad. I saw pretty colors. I will edit with a better one.

4 Likes

like @Caustic i use TL072

3 Likes

Thank you, I’ll give this a go (cheap as chips!)…the spec sheet doesn’t look like anything very special. Noise is a problem, as the output will be very near my ear. Nothing ventured nothing gained. :slight_smile:

there is also LM358 but i don’t know if it’s better or not

just for curiosity, it’s for what circuit ?

TL07x (a low noise version of TL08x) is the standard workhorse for synth builders. Cheap, widely available, reasonably good for most purposes, and has been around forever and will be around forever. There are many many more modern options, most of which better at something. At least on paper.

But I don’t think you’ll find many strong opinions about opamps here. That tends to be reserved for the forums where people who build headphone amps hang out. Check there and you’ll find enough biased tests, cargo culting, and strong opinions to last you for several lifetimes :smiley:

7 Likes

It’s going into a small op-amp based earphone amplifier. I was impressed by the TI 1622’s ability to push up to 145 mA, plus a very low noise level so I don’t get that infuriating hissssss… rather less hiss…

2 Likes

It’s why I posted here, ideas and opinions far outside the norm… plus people here actually build circuits. Not just spec sheet junkies… Ideas, chips to buy and try. Noise to hear, spec sheets to glance at, eyebrows to raise or lower… Plus, I just like the people here.

3 Likes

The TL072 or LM358 mentioned here are probably not what you want for a headphone amp, especially if you want extra drive capacity (I’ve seen designs with a transistor stage or dual TL072s in parallel (iirc, or was it bridge?) but no idea how well that works).

On the other hand the 8-pin dual opamps have standardized pinouts, so you could just test the ones you can get your hands on in circuit (it’s your ears, after all :slight_smile: and only you know if a given amp affects the sound in some way you like). And there might be headphone amp builders here, who just haven’t shown up in this thread yet.

(I myself is at the “whatever amp is in my bluetooth headphones and I only listen to loud music anyway so what is this noise thing you’re talking about” level wrt headphone amps :smiley:).

2 Likes

Ah, too low drive current for a headphone amp? Ok, no want to do parallel op-amps it just seems like a kludge. Ear buds are hard to spec for, they cut out all the surrounding noise, so you get to hear your circuits noise in its entirety. I’ve used noisier op-amps for over ear headphones that I like the sound of before now. Like the sound of the older OPA1612, not sure which supplier does the 1622 though… CPC doesn’t do many, they’re mostly for passives and generic bits and bobs. Got to be a DIP8 part, with no overhangs.

Heh… loud = good! the in-between song hiss drives me nuts though.

4 Likes

I mentioned in another thread of a Peavey mixer I’ve have schematics for and I’m planning to build (maybe to fit in my Eurorack)…

They use 4558 dual op-amps exclusively throughout the mixer. On the channel pre-amps, unbalancing the balanced inputs, and throughout the main bus… I’ve picked up a tube of 10 from Farnell (like £2 or something silly), so will have a play.

Need to figure out what needs changing to shift the design from 15v to 12v :roll_eyes:

OPA 2134 best all around

Another approach for headphone amps which I’ve seen outlined in Douglas Self’s Book is to use an op-amp that drives a discrete transistor output stage.

Cheers