The preamp I think is, along with speakers the component that will make or break a system. Is the Acurus power amp a tube unit or solid-state? The thing about many passive preamps is that the quality of their performance can depend somewhat on the output impedence of the source and input impedence of the amp. With high impedence output at the source, it can be advisable to use cables that are 3 meters or under for best performance, and the same goes for the the amps, although up 4 meters for best performance. What cables are you using and how long are they? My Bent TAP does not have such limitations as it is transformer-based, But resistor type passives will be more sensitive to this I think. Also the Bent has 6DB of gain available if required - which for me it definitely isn't - rather the opposite. Despite any possible impedence limitations, the upside of passives is the performance is excellent. Most preamps you've heard will sound muddly, cloudy and lack the clear precision. Good passive have lots of detail, which is a good thing I think. The Bent TAP preamp has not sounded dull or lifeless in the least during my listening so far. If you can find a way to audition one at another audio enthusiast's house, then you can see if the sound appeals to you; It does to me for sure. Others of interest are Music First Passive Magnetic, Promethious, Placette RVC and a few others.