I bought a pair of both Muses 02 and V7Vs. The Muses showed up 2 weeks earlier than the V7Vs, which arrived this morning. Running an External Dac (Topping DX7 Pro) into the ZA3 via XLR. For the last 2 weeks I've had the Muses02 in the L & R Slots, stock in the XLR slot and pulled the 2 stock OpAmps for the Sub Out as I'm not using it. With the Muses there was a clear improvement over stock with better resolution across the board and perhaps a bit more depth to the sound field, however, I did find the mids a little forward and thin for my liking and bass not as deep as I'd like - but better and I could add to it with PEQ.
Today the V7V arrived so I performed my morning surgery procedure. I moved 1 Muses02 to the XLR Slot and dropped the V7Vs into the L & R Channels. To be honest at first I was a bit disappointed - it was marginally better sounding with a bit more weight in the mids and bass but I found the treble lacking. I let the system run for an hour and I could hear it all opening up. The Amp has now been running approx 8 hours and I'm absolutely delighted. The treble region has developed more air and more crispness and bass lines have got better definition to them. For me a very good upgrade.
I've got a second ZA3 I haven't even taken out of the box yet. I was going to run them as Monos but there's so much power coming out of a single unit, so much low level volume - I dont need the 2nd one. I'm going to list it. I've got everything I need and want with a Single ZA3 and 2 x V7V + a Muses02