Feature:1. * With wide applied range and practicability, it can fit the majority of active speakers and power amplifiers in the market.2. * The replaceable 6K4 vacuum tubes design can optimize the circuit.3. * The audio part and the power part are completely separated, which minimizes the interference to the sound.4. * The timbre is soft and beautiful, sweet and warm and with powerful bass, penetrating treble.5. * With treble and bass adjustment, single power supply, it\u0027s small and portable, brings you much fun and conveniece.6. * Using high-quality aluminum alloy housing with gold-plated connectors, it\u0027s durable and high-performance.Specification:Overview:With a wide applied range and practicability, this preamplifier can fit the majority of active speakers and power amplifiers in the market. The replaceable 6K4 vacuum tubes design can optimize the circuit. The audio part and the power part are completely separated, which minimizes the interference to the sound. The timbre is soft and beautiful, sweet and warm, and with powerful bass, penetrating treble. With treble and bass adjustment, single power supply, it's small and portable, brings you much fun and convenience. Using high-quality aluminum alloy housing with gold-plated connectors, it's durable and high-performance.Features:* With a wide applied range and practicability, it can fit the majority of active speakers and power amplifiers in the market.* The replaceable 6K4 vacuum tubes design can optimize the circuit.* The audio part and the power part are completely separated, which minimizes the interference to the sound.* The timbre is soft and beautiful, sweet and warm, and with powerful bass, penetrating treble.* With treble and bass adjustment, single power supply, it's small and portable, brings you much fun and convenience.* Using high-quality aluminum alloy housing with gold-plated connectors, it's durable and high-performance.Specifications:Model Number: TUBE-03Tube Model: 6K4Frequency Response: ±1.5(20Hz-20KHz)Audio Input Interface: RCAAudio Output Interface: RCARCA Output: 0.9VrmsSNR: 100dBTHD: 0.03%Treble Adjustable Range: ±6dBBass Adjustable Range: ±10dBInput Voltage: AC 100-240V, 50/60Hz; DC 12V/1AColor: Black, Silver (Optional)Main Item Size: approx. 12 * 9.8 * 3.3cm / 4.72 * 3.85 * 1.29inMain Item Weight: approx. 318g / 11.21ozPackage Size: approx. 22 * 21 * 7cm / 8.66 * 8.26 * 2.75inPackage Weight: approx. 566g / 19.96ozPackage List:1 * Preamplifier1 * Power Adapter1 * User Manual (English & Chinese)Package List:1 * Preamplifier1 * Power Adapter1 * User Manual (English & Chinese)