PSVANE Matched Pair Vacuum Tube ACME Series KT88 Tubes Amplifier Preamp (2 PACK)

After a lot of research, I ordered 2 pairs of Psvane ACME KT88 tubes for my Muzishare X7 amp. Although I am a collector of mostly 50’s and 60’s amplifier tubes, I am new to KT88’s. So, this review will not be a comprehensive comparison of KT88’s, just my experiences. I have owned the Muzishare amp since COVID and updated the preamp tubes with 1950’s RCA long black plates, which made the amp warm and delightful to listen to; basically a huge improvement over the stock tubes. I also changed the rectifier to a Mullard Blackburn. The last 4 years or so, I have been very happy with the sound quality with over 1000 hrs on the amp and original KT88’s. I figured I was done tube rolling and a happy camper. When Psvane tubes were available on Amazon, with a 30 day return policy, I decided to give another look at changing the power tubes.I placed my Amazon order and the tubes were delivered via DHL in about a week. As shown in the picture, the tube packaging was very impressive and secure. Before I plugged them in my amp, I tested them and found that they were right on the KT88 spec and amazingly, the plate current on all 4 tubes was within a couple of mAmps of each other at various test voltages. All 4 tubes were easily within 2%. Probably the best matched tubes, I have ever purchased. I installed the tubes and with no burn in hours they sounded more open, with greater presence and more clarity than the stock tubes. Three other interesting observations: they have slightly more bass…just a bit, they required me to adjust the bias down about 20% from were it was set on the stock tubes and they seem to operate a bit cooler. Lastly, as shown in the pictures, they are well constructed and wonderful to look at. Now with 10 hours on them, I am very happy with the Psvane KT88 tubes and I am looking forward to any sonic changes that will assuredly occur with time and use.