Overview: This preamplifier offers broad compatibility and practical design, suitable for most active speakers and power amplifiers on the market. The circuit is optimized with replaceable 6K4 vacuum tubes. o and power sections are fully separated to minimize interference, delivering clear, warm sound with strong bass and detailed treble. Features include treble and bass controls, single power supply, compact size, and portability for convenient use. Constructed with a high-quality aluminum alloy housing and gold-plated connectors for durability and reliable performance. Features: * Wide compatibility with most active speakers and power amplifiers * Replaceable 6K4 vacuum tubes for optimized circuit performance * Fully separated o and power sections to reduce signal interference * Warm, smooth sound signature with enhanced bass and clear treble * Adjustable treble and bass controls for customized o output * Compact, lightweight design with single power supply for easy portability * Durable aluminum alloy housing with gold-plated RCA connectors Specifications: Model Number: TUBE-03 Tube Model: 6K4 Frequency Response: ±1.5dB (20Hz–20kHz) o Input: RCA o Output: RCA RCA Output: 0.9Vrms Signal-to-Noise Ratio (SNR): 100dB Total Harmonic Distortion (THD): 0.03% Treble Adjustment Range: ±6dB Bass Adjustment Range: ±10dB Input Voltage: AC 100–240V, 50/60Hz; DC 12V/1A Color: Black, Silver 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 Contents: 1 x Preamplifier 1 x Power Adapter 1 x User Manual