Supersonic V1

I added a pair of these to a Fosi audio ZD3 replacing Sparkos Labs op amps. What an improvement, it was as if a veil was removed from my music. Very detailed, along with a huge improvement in soundstage. Two thumbs up, great price, and outstanding sound.

I added the V1 to my fosi za3, wow. Not sure how to describe the difference, but it is clearly better. Loving it

It installs easily inside the Fosi V3 Stereo. After a few hours of burn-in, the sound took shape and became smooth and rich. Very happy with this real upgrade. Thank you Greg