OPA2134 Stability

Preliminary listening tests seem to indicate that the prototype is for all practical purposes sonically transparent. On my tape monitor, with the prototype powered with 9 volt batteries, I could not hear a difference. And there are no nasty habits.

I will install the prototype into my preamp and listen to it for a while. If it works out, then I will build a 40 Hz version for my 8" two ways and see how that works.
 
After listening to this for a few days I must say that it works very well. It adds nothing but it does get rid of the subsonic trash. All my poles are 1.6 Hz or 3.2 Hz so without a filter like this the subsonic trash comes right through to the speakers. And there's a lot of it on some CDs and on streaming and MP3 music too.

This really improved my 8" two ways a lot, and I'm hoping that a 40 Hz version will work better. The speakers are electronically compensated for bass response (shelving equalizer +3dB@80 Hz and +5 dB at 40 Hz) so unwanted low frequencies are boosted. The party's over at 40 Hz so I'm thinking that a 40 Hz high pass filter like this will allow more dynamic range and higher max spl. The 20 Hz version will go in my biamp, which will drive subwoofers and satellites.