Review on Nobsound 12AX7 12AU7 Vacuum Tube Preamp HiFi Preamplifier - Unleash Audiophile Excellence! by Juanita Valentin

I really like the sound quality of this inexpensive tube preamp. It's supposedly based on the classic Marantz M7 design, but I'm not sure because I haven't reverse engineered the circuitry yet. The included Chinese lamps seemed a bit flat for my taste, even after 24 hours of warm-up time. Instead, I installed some nice old JJ Tesla light bulbs that I bought on eBay through Viva Tubes. Now the device has a rich, expensive sound that will appeal to most serious music lovers. Now I can listen to my vinyl for hours without getting tired. Even my wife commented on how open and airy the wide soundstage was. Actually I like it! I had to install a ground wire between my Phase Linear 700B power amp and this preamp, I also added a nice vintage Pioneer 10 band EQ between this preamp and the power amp and now it really sounds like a concert! Feel free to ask me any technical questions as I'm an electrical engineer with over 25 years of audio engineering experience. Enjoy!