yaqin mc100b upgrades

I feel that I obtained a big improvement in sound when I had my tech change six capacitors to 4-Silver Oil Mundorf's (in the audio signal path) and 2-Jantzen Silver (not directly in the audio signal path). Another significant improvement in my opinion was obtained when I changed out my Treasure Series KT88's with Tung-Sol KT120's and increased the bias based upon my plate voltage using Ohm law. I also prefer the sound of using Sylvania 5751 black plate gold bands over the sound achieved using Telefunken 12AX7's smooth plates. However, the Telefunken's may have been technically more neutral sounding. Bypassing the preamp stage by using the RCA inputs on the front while switching to .6v gain provided a small improvement as well. Using the KT120's increased the dynamics and sound stage and provided a deeper,tighter more defined bass. I use KenRad VT-231 6SN7's (Black Glass) in V1 through V4 but often switch or mix them up with Sylvania 6SN7W (Short Bottles). The Sylvania short bottle tubes are very dynamic and provide more punch to the sound. I also really like the sound produced from using Shuguang Treasure Series CV-181's, although you will need to obtain a tube adapter since the stock base of the CV-181's will not fit tightly into the recessed tube sockets due to their larger diameter base. I actually use socket savers generally used with tube testers and they work fine.