5Pcs OPA2604AP DIP-8 Dual FET-Input Low Distortion Operational Amplifiers

All worked well. I swapped with NE5532p. They sound smoother, more detailed.

It works great in my old altoid's CMOY. It adds a nicer bass kind of sound to my headphones. From my point of view it really shines best with my grados and dt990 pro 250 ohm headphones. Totally worth it.

These are genuine op amps and they made my zd3 za3 and zh3 by fosi audio sounds so much better

These were the third op amp I tried in my Douk amp, and easily the best sounding. I did have a failure of one chip. While playing at high volume there was a sudden metallic, percussive noise from the right speaker. Later I realized there was a steady low level hiss from that speaker. I swapped out both op amps, which fixed the noise. All is well, so far. I do realize that the authenticity of these chips is in question so time will tell. They do sound marvelous, rich and detailed.

these chips made my duok P1 Plus sound better and they are a bargain. there is a youtube short that says these are fake but the op amps are built to specs and I don't think the person auditioned them and they are being picky-picky.

I bought these to go with my new class D amp the Aiyima A07 great fit and great sound. Such a great value and way to improve the sound of your amps or preamp.

These were fine. However, I could not tell the difference from my current op amp, so I returned them.

Good sound, Just hard to install as legs are pretty soft and tend to bend under pressure.