Replacement op amps for BT20A PRO.

Different op-amps can produce varying sound qualities. Please refer to video https://www.youtube.com/watch?v=oyFbNseAJQ8

Here are some genuine suggestions from users.

To anyone on ASR who thinks all OP AMPS sound the same, you can clearly hear differences even in this video!  The NE5532 these come with are not exactly pristine quality, yet still sound overall best in this video.  I even found swapping to genuine NE5532 from Digi-key made my Fosi Audio Tube preamp sound even better and punchier.  The LME49720 I found to be better in the bass than the treble, the metal versions with an adapter would be even better.  Just do not expect it to make your system sound way better by doing this, the speakers and amplification are the most important and must be up to snuff.  You can improve the sound a bit, but you can also make it sound worst.

If you prioritize absolute sound quality and transparency, the MUSES02 might be the best choice for you. If you are looking for a versatile op-amp that offers a balanced performance across different audio applications, the OPA2604AP could be a suitable option. On the other hand, if you prefer a slightly warmer and more musical sound, the OPA2134PA might be more appealing. Someone has excellent experience with the SPARKOS LABS SS3602 Discrete dual channel Op Amp.

Ss2590: It almost Very very clear, Like a very High end