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

Build Quality: Inexpensive but functional tubes. A cheap selector switch can get stuck between inputs and cause audio to be muted. OK, potentiometer. Capacitors with WIMA inscription. The power transformer is 110V, which is different from the 115V in the picture above. Most importantly, the entire setup is not properly grounded which creates a ground loop unless I somehow connect the input to my Pro Power Amps. Sound Quality: Fairly good after grounding. Slightly mid-centered, but with a subtle flare on either side. This is different with the 6H11 power amp, which noticeably dampens high frequencies. Odor: does not smell like pesticides like the 6H11 booster.