Overview: This preamplifier offers wide compatibility and practical design, suitable for most active speakers and power amplifiers on the market. The replaceable 6K4 vacuum tubes help optimize circuit performance. Audio and power sections are fully separated to minimize interference and enhance sound clarity. It delivers smooth, warm sound with strong bass and clear treble. Equipped with treble and bass controls and a single power supply, the unit is compact and portable, providing convenient audio enhancement. Constructed with a high-quality aluminum alloy housing and gold-plated connectors, it ensures durability and reliable performance. Features: * Wide compatibility with most active speakers and power amplifiers * Replaceable 6K4 vacuum tubes for optimized circuit performance * Fully separated audio and power sections reduce signal interference * Smooth, warm sound quality with enhanced bass and clear treble * Treble and bass adjustment controls; compact and portable design * Durable aluminum alloy housing with gold-plated connectors for reliable connectivity Specifications: Model Number: TUBE-03 Tube Model: 6K4 Frequency Response: ±1.5dB (20Hz–20kHz) Audio Input Interface: RCA Audio Output Interface: RCA RCA Output: 0.9Vrms Signal-to-Noise Ratio (SNR): 100dB Total Harmonic Distortion (THD): 0.03% Treble Adjustable Range: ±6dB Bass Adjustable Range: ±10dB Input Voltage: AC 100–240V, 50/60Hz; DC 12V/1A Color: Black, Silver (Optional) Main Item Dimensions: approx. 12 x 9.8 x 3.3cm (4.72 x 3.85 x 1.29in) Main Item Weight: approx. 318g (11.21oz) Package Dimensions: approx. 22 x 21 x 7cm (8.66 x 8.26 x 2.75in) Package Weight: approx. 566g (19.96oz) Package List: 1 x Preamplifier 1 x Power Adapter 1 x User Manual