Looking at the specs, there doesn't seem to be any reason to use the 24bit setting going line in. If the noise floor is only 90db down, those last 8 bits are all noise.
^^This is my feeling when using any palm-sized recorder.
I have the Nagra SD. Build quality is excellent.
When running unblanaced line in from a SD Mixpre-D, (XLR out unblanaced),
I turn on the -20dBsf slate tone on the Mixpre, and with the NagraSD line input turned all the way down, it's recording the tone at -18.89dBfs.. both channels. exactly the same.
I put the test tone in a DAW and that's what it comes in at.
Nagra peak light comes on at 0dBfs. There isn't any distortion that I can tell.
There isn't any limiter.
When using mic input the peak light comes on at 0dBfs or when you clip the internal mic preamp.
It's very easy to use.
Yes, noise floor not as quiet as other palm-sized recorders... but that's not the whole story about the quality of the sound.
My RO9-HR is a couple dB quieter, but the sound is slightly duller.
I did e-mail Nagra several times and asked these questions...
Can you make the noise floor quieter?.. answer was "yes, at the expense of battery life.. it's all about power... we could make it with a different chip, but battery life greatly reduced."
Does the line level input bypass the mic preamps?.... answer was "yes."
The review from this AEQ-L300 says it's different software than the Nagra.... but it looks the same.
One thing different.... the latest Nagra software the record button stays solid red while in record, and the AEQ blinks faster when in record.
This is how early version of the Nagra SD software was. Would be interesting to see if you could load the Nagra Lino Software.