Over the last two years, I performed the following upgrades to my system:
- Upgraded the crossovers in my SDA-2B’s (Sonicap high pass, Solen low pass, Mills resistors)
- TL’d my SDA-2B’s (RD0198-1 tweeters and added 5.8 uF capacitor in parallel with the 2.7 ohm resistor)
- Modified my Yamaha CD-745 CD player with better opamps (AD843 and AD8620)
- Upgraded my integrated amplifier to a NAD C370
The improvements were dramatic from where I started but the sound was a little sterile and mechanical sounding. After reading some of the discussions on this forum and others, I started wondering if tubes were the answer. I had always assumed that “tube sound” was warm but mushy. Some of the posts I read convinced me that “tube sound” was probably not what I thought. I decided to order a Yaqin Tube Buffer with a JJ/Tesla 6922 tube and installed it in the pre-amp out/main-amp in loop of my NAD C370.
Wow – “Tube sound” is wonderful! The difference is subtle yet profound. It’s a subtle difference if you A/B the system by turning the tube buffer on and off. When you sit back and listen for a few minutes, the difference is profound.
Bass is a little smoother but, much to my surprise, no less punchy. Mids and highs are more liquid but not soft at all. Vocals sound more realistic and cymbals actually sound like cymbals. It sounds only a little warmer but much sweeter and richer. Details used to sound somewhat disconnected from the music. Now the details are part of the instruments, vocals, etc. The details don’t hit you in the face like they did before but separation between instruments and vocalists is much more distinct and airy.
I think I finally understand what the magazine writers mean when they talk about a system conveying “emotion.” Instead of getting bored after a while, it keeps me smiling. The music is much more alive. I’m finally listening to the music instead of analyzing the sound.
The Yaqin Tube Buffer was $175 and the upgraded tube was $11 from Pacific Valve and Electric. With shipping, it came to $216. This one has a good $ to smile ratio for my system!