I'm considering an op-amp for making a DC coupling adapter to a soundcard to
convert it to signal logging purposes while retaining its audio performance.
It uses a passive adder and a gain of 2 to add a bias voltage to the signal
before an ADC input.

The sound card is one with external analog circuitry in a rack unit, it has
20 bit signal conversion, so this op-amp will have to be good to maintain
that and the other specs this unit has.

I looked first at a few audio amps and noticed that their claims for CMRR and
open-loop gain often fall well short of the claims made for the equipment
they go into, but never mind, that's another issue for another day..

Then I looked at a DC instrumentation amp (OPA2277) I'm using in a laser
power meter design. If I can use it, it saves me buying varieties of
expensive chips in small quantities. Audio boffs high, wide and plentiful
will say don't do it, slew rate is slow, etc, but is it?? 0.8V/µS. It doesn't
sound a lot when people are saying I need 16V/µS or whatever, but I
calculated it, and it looks fine to me. The sound unit I'm adapting to is
considerably better than CD quality, sampling with 20 bits at up to 48 KHz,
and I calculated that this means a sample at intervals of a tad over 20 µS.
As 20 µS of 0.8V/µS is 16V, and as the device I'm adapting to has a ±15V
supply and a differential input design that halves the input, the largest
possible voltage change will occur, and fully settle, in the time between
samples at highest sample rate available.

As all the other figures for dynamic range and noise are so good that they
will allow the original specs for the entire unit to remain intact, is there
any reason I should not use this op-amp? It's a lot cheaper than any audio
amp that looks like it will do as well as this. And as I'm after DC as well
as AC capability, it seems that this is the right decision, but I'm
interested in other views before I decide anything. (I could just use
sockets, but for a low profile board I'll be soldering it in, and don't want
to have to mess with that later.