On a sunny day (Sun, 1 Mar 2020 08:56:41 +0000) it happened The Natural
Philosopher  wrote in :

>Bifet is not bad but there exists today an opamp that is low enough
>noise to match the very best discrete circuit that I used to design back
>in the 70s .

Oh, sure
I am not uptodate on what the latest and greatest is (ask in
sci.electronics.design if you need to know)
but bought a few TCL274 quad opamps a few month ago as sort of universal opamp
for projects, specs:

 Trimmed Offset Voltage:  TLC279 . . . 900 µV Max at 25°C,
          VDD = 5 V
 Input Offset Voltage Drift . . . Typically 0.1 µV/Month, Including the First
30 Days
 Wide Range of Supply Voltages Over
 Specified Temperature Range:
       0°C to 70°C . . . 3 V to 16 V
       ­ 40°C to 85°C . . . 4 V to 16 V
       ­ 55°C to 125°C . . . 4 V to 16 V
 Single-Supply Operation
 Common-Mode Input Voltage Range  Extends Below the Negative Rail (C-Suffix and
I-Suffix Versions)
 Low Noise . . . Typically 25 nV/Hz  at f = 1 kHz
 Output Voltage Range Includes Negative Rail
 High Input Impedance . . . 10^12 Ohm Typ
 ESD-Protection Circuitry
 Designed-In Latch-Up Immunity desription

Much better than the LM324 :-)


>I think unity gain on CMOS is a lot more than 1Mhz tho.

Oh yes, and there is,  after the CD4000 series,  the 74HC4000 series.

The TCL274 has a gain of 1 at about 1 MHz, but I typicaly use these things for
measurement equipment design.
Not done much audio lately, apart from funny little things like this:
  http://panteltje.com/panteltje/pic/audio_pic/
These days you can get a decent PWM 80W audio amp for next to nothing from
ebay...

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