For the most natural sounding line conditioner, look no further than the Acoustic Revive RTP-4 Ultimate. The RTP-4 Ultimate is the culmination of all the vibration and noise control technology seen on their other products into this line conditioner. Google for the link where you can read more about the impressive way it is built and the kind of exotic materials used – Duralumin, Green Carborundum, Tourmaline powder, natural quartz powder etc.
The amazing thing about the RTP-4 Ultimate is its ability to cast a darker and quieter background. Music flow was smoother and a tad more organic sounding. We found the improvement greatest when a CD player (or any other digital sources) and preamp is plugged into its two outlets. As for amplifiers, we found tube amps reaping the most benefits when plugged into it. One thing to take note though, the RTP-4 Ultimate is NOT a surge protector but a top notch power conditioner. If you want to have some protection for your system, just have a simple surge protector placed before it. The top plate has some scratches/scuff marks but no impact on performance of the RTP-4 Ultimate. They are not sold with AC cord but previous got so bowled over by the improvements it brought into his system he bought the Power Reference AC cable ($1,600 MSRP) to pair with it. This AC cable (2m long) is included in the price making this combo the best deal out there now. Both items will be securely packed for safe shipping.