FOZI ZA3 with Burson V7 Classic Opamp

On my Fosi ZA3 amp, I changed two original Dual Opamps (1 per channel) for a Burson Dual Opamp V7 Classic Kit. The original sound was lively/dynamic and the soundstage was well balanced. From bass to treble, the sound was good too but a little harsh in the treble on some recordings. The V7 Classic adds more depth, opens up the soundstage and adds silky smooth mids. Jazz trios and quartets are therefore surprisingly good as well as the voice with piano and acoustic guitar. On the other hand, the lively/dynamic sound has disappeared and the bass and treble are less resolved. I think my V7 Classic kit has a problem because one of them is about +3 dB louder than the other one. And one of them is always hotter to the touch than the other one too. I'm going to buy a new V7 Vivid kit to test the sound and see if I have the same problems.