OPAMP recommendation in quad package

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user 37518

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Hi everyone, I need to build a circuit with several opamps and I am looking for opamps in quad configuration. I don't care if its SMD or through hole as long as it is either SOIC or DIP.

I prefer a bipolar opamp but a low noise FET will do, the LME49740 would've been perfect but it is now discontinued. I am looking for opamps similar to an NE5532, LM4562 or OPA1612, the first one that comes to mind is the OPA4134 which is the quad version of the FET OPA134, I would like something with less voltage noise and similar driving capabilities aswell as +/-15V supply capable. I don't need extra wide bandwidth or very high Slew Rate, I prefer an opamp which is unity gain stable and not that picky for layout, any recommendations?


The OPA1679 looks nice https://www.ti.com/lit/ds/symlink/opa1679.pdf?HQS=TI-null-null-mousermode-df-pf-null-wwe&ts=1601526748998&ref_url=https%253A%252F%252Fwww.mouser.mx%252F The price is quite affordable and the specs are almost the same as an NE5532. According to the simplified internal schematic it seems to be a MOS opamp, any experiences with it?
 
Both seem like really good options, thank you, the MC33079 is dirt cheap, the OPA1644 is considerably more expensive.

One question about the MC33079, Jakob, can it drive 600 ohm loads without crying? the datasheet says it can supply a good amount of current, but the THD plots are made considering a 2K load, I might not load it with 600ohms but I will certainly do it with 1K. The OPA1644 seems to be able to drive 600 ohm loads with its corresponding increase in distortion, however, its still quite low.
 
just had a look at 1642 datasheet and was suprised by its excellent lowlevel distortion.
better than opa1612.
 
5v333 said:
just had a look at 1642 datasheet and was suprised by its excellent lowlevel distortion.
better than opa1612.

Yes but much higher noise, however, for a FET opamp its quite low, seems like a better alternative to the OPAx134 which costs around the same.
 
If you dont need super low noise in all circuits you could use a dual better opamp for gain and 1644 for the rest perhaps..?
 
user 37518 said:
Both seem like really good options, thank you, the MC33079 is dirt cheap, the OPA1644 is considerably more expensive.

One question about the MC33079, Jakob, can it drive 600 ohm loads without crying? the datasheet says it can supply a good amount of current, but the THD plots are made considering a 2K load, I might not load it with 600ohms but I will certainly do it with 1K. The OPA1644 seems to be able to drive 600 ohm loads with its corresponding increase in distortion, however, its still quite low.

The OPA1644 noise is down at 5.1-nV/√Hz. I like em' quiet :)
 
The Analog AD713 is still available, even in a DIP package, and it's a nice BiFET quad, basically like a TL074 that's around 10dB better in every way. Less offset, noise, distortion, etc. It's pricey now and probably not worth the bother these days, especially if you can rig up something more modern, but back a long time ago with Neotek consoles (which are full of quad BiFETs) the AD713 was a nice way to retain the basic TL074 character but make everything a little nicer. For that console, which needs DIP parts, SMD adapter boards stuffed with modern dual op amps is probably the right way to go. There are so many fine op amps available now. Still, the 713 is a good way to have something like a TL074 that's just a little bit more refined with all of the same characteristic flaws.
 
Monte McGuire said:
The Analog AD713 is still available, even in a DIP package, and it's a nice BiFET quad, basically like a TL074 that's around 10dB better in every way. Less offset, noise, distortion, etc. It's pricey now and probably not worth the bother these days, especially if you can rig up something more modern, but back a long time ago with Neotek consoles (which are full of quad BiFETs) the AD713 was a nice way to retain the basic TL074 character but make everything a little nicer. For that console, which needs DIP parts, SMD adapter boards stuffed with modern dual op amps is probably the right way to go. There are so many fine op amps available now. Still, the 713 is a good way to have something like a TL074 that's just a little bit more refined with all of the same characteristic flaws.

Jeez, its around $20 USD each.
 
scott2000 said:
A few AD713JN here for less. Have had good luck in the past with them....

https://rcfreelance.com/search.php?q=ad713


How many 49740 would you need for your project?

Thanks for that link, I'll be needing around 10 of them.
 
user 37518 said:
I'll be needing around 10 of them.

This place was brought up here before...The member here was looking for a group buy since there is a minimum of 122. Digikey uses them as one of their Marketplace distributors apparently.......

https://www.rocelec.com/part/tislme49740na-nopb

I have a few, not sure about 10...... could check later if you are still set on using them and haven't gone another direction. Just PM me.
 
scott2000 said:
This place was brought up here before...The member here was looking for a group buy since there is a minimum of 122. Digikey uses them as one of their Marketplace distributors apparently.......

https://www.rocelec.com/part/tislme49740na-nopb

I have a few, not sure about 10...... could check later if you are still set on using them and haven't gone another direction. Just PM me.

Paradoxically they also list prices for smaller amounts...
 
user 37518 said:
LME49740 would've been perfect but it is now discontinued.

Very unfortunate :( I was about to recommended it over anything.

I suppose with DIP going away and smaller sizes taking over, quad is not really needed for anything. No price or size savings to be had anymore.
 
Kingston said:
I suppose with DIP going away and smaller sizes taking over, quad is not really needed for anything. No price or size savings to be had anymore.

The biggest benefit of using quad, in my opinion, is that you need less +/- Vcc lines and less coupling capacitors than 2 duals.
 
user 37518 said:
The biggest benefit of using quad, in my opinion, is that you need less +/- Vcc lines and less coupling capacitors than 2 duals.
Most often I found that quads need more intricate layout, since more things must converge to the same spot. Regarding decoupling caps, I would often double the value for a quad than for a dual.
Indeed there are some cases where they make sense, such as quad comparators for a bargraph.
 

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