Hello, You are in luck. I had a CJ PV-7 and the PS Audio 4.6 preamps and I used them both with a B&K ST-140. I replaced the PS 4.6 with a PS 5.5 and then upgraded to the CJ PV-7. The PV-7 was the best sounding of the bunch. Both PS Audio pre-amps were very quite and had very good dynamics. They both sounded best in straightwire mode. The PS Audio preamps had one advantage over the CJ. They could be left in standby mode without any worries about tube burnout. The CJ couldn't be left on all the time. It had to warm up before it sounded its best. The CJ was also very quite, but it wasn't as fast. It did however make wonderful music. I loved the way that the PV-7 complemented the ST-140. The ST-140 is a good mellow sounding amp that sounded great with an easy to drive speaker. The B&K amp had trouble with a 4 ohm load like the KEFs that I was using, but really shined with a pair of ADS 1290s. Overall the PV-7 was at least the equal of the PS 5.5 which was an improvement over the 4.6 preamp. When it was time to upgrade my system, the PV-7 was so good that I kept the CJ PV-7 and upgraded the amp. I have since upgraded to the PV-11 which sounds like the PV-7, but just more of a good thing. Conrad Johnson has excellent resale value. You can also sell the PV-7 three years from now for more than you paid for it. I also still have the 5.5 in a bedroom system. Jim