Signature IIa

About the Signature IIa

Introduced in 2011 as an evolution of the Signature II, the Signature IIa preamplifier by Valve Amplification Company offers 12 dB gain with a frequency response flat over the audio band and an output impedance of approximately 96 to 150 ohms. It uses a fully balanced, transformer-coupled Class A1 triode topology with no coupling capacitors or loop negative feedback, ensuring purity and stability in the audio signal. The linestage comes stock with two 12AU7 twin triodes and two E88CC tubes, which are swappable. It features six standard line inputs (five when phono is fitted), a fully balanced Cinema Bypass input, and outputs include two pairs single-ended RCA and two pairs balanced XLR. The optional six-tube phono stage supports MM and MC cartridges with adjustable gain and resistive loading, electrostatic decoupling to prevent heater circuit interference, and a separate power transformer to isolate the phono signal from the line stage. The chassis is designed with improved damping and energy termination solutions, and the faceplate is a sculpted 3/8" thick metal with backlit VAC logos that glow blue during operation and red when muted. The preamp is praised for its clean, punchy, and natural sound with excellent timing, detail, and finesse, making it suitable for a wide range of music genres. Dimensions are approximately 17.8" W x 5.5" H x 14.4" D for the audio chassis, with a separate power supply unit. The unit weighs about 61 lbs with the phono stage installed.