{"product_id":"2pcs-uotang-t803-passive-bookshelf-speakers-8-inch-3-way-hifi-home-stereo-speakers-mk9000-tube-amp","title":"2PCS UOTANG T803 Passive Bookshelf Speakers 8-Inch 3-Way HiFi Home Stereo Speakers + MK9000 Tube Amp","description":"\u003cp\u003e\u003cspan style=\"background-color: rgb(255, 255, 0);\"\u003e\u003cb\u003eOptional Configuration:\u003c\/b\u003e\u003c\/span\u003e\u003cbr\u003e* T803 Speakers\u003cbr\u003e* T803 Speakers + MK9000 Tube Amp\u003cbr\u003e\u003cbr\u003e\u003cb\u003e\u003cspan style=\"background-color: rgb(255, 255, 0);\"\u003eT803 3-Way Speakers:\u003c\/span\u003e\u003cbr\u003e1. Features:\u003c\/b\u003e\u003cbr\u003eUOTANG T803 8-inch 3-Way Carbon Fiber Loudspeaker\u003cbr\u003e* 3-Way Passive Bookshelf Speaker\u003cbr\u003e* 200MM 8-inch Pure Woofer Unit\u003cbr\u003e* 30MM Tweeter with Silk Soft Dome Diaphragm\u003cbr\u003e* German 12K Carbon Fiber Mid-range\/Woofer Diaphragm\u003cbr\u003e* UOTANG Self-Developed Wave-Shaped Ridged Surround Technology\u003cbr\u003e* 100MM 4-inch Pure Mid-range Unit\u003cbr\u003e* DuPont Fiber Mid-range\/Woofer Surround\u003cbr\u003e* American LINEARXSYSTEM LMS Acoustic System Testing\u003cbr\u003e* Finnish Birch Plywood Cabinet Veneered with Brazilian Solid Wood\u003cbr\u003e* LINKWITZ-RILEY Crossover Circuit\u003cbr\u003e* Fully Symmetric Low-Distortion Magnetic Circuit System\u003cbr\u003e* Horn-Shaped Asymmetric Port Tube\u003cbr\u003e* Hook-and-Loop Grille, No Cabinet Screw Holes\u003cbr\u003e* Shock-Absorbing Spikes for Audiophile-Grade Use\u003cbr\u003e* Bi-Wire Design for Effortless Driving\u003cbr\u003e\u003cbr\u003eComposed Calm and Steady Texture. Crystal Clear Sound Reaches Your Soul\u003cbr\u003e* It is equipped with a large-diameter 200mm 8-inch pure woofer unit and a large-diameter 100mm 4-inch pure mid-range unit. The cone is made of lightweight high-strength German 12K carbon fiber material, integrally formed with thermoplastic elastic material via UOTANG's wave-shaped ridged surround technology. You can immediately perceive the bold and stable sound performance of the T803 at first listen. Its 30mm silk dome tweeter unit is fitted with customized damping glue to greatly enhance damping, reduce resonance interference, and deliver clean, accurate, transparent and pure treble. It adopts a 50mm large voice coil and DuPont fiber mid-range and woofer surrounds, paired with an integrated die-cast aluminum-magnesium frame and fully symmetric low-distortion magnetic circuit system. It undergoes LMS acoustic system testing by LinearxSystem, and the cabinet is constructed with Finnish birch plywood covered with imported Brazilian solid wood veneer.\u003cbr\u003e\u003cbr\u003eImmerse Yourself in Pure and Transparent Sound and Accompany You Into a Clear Auditory Wonderland\u003cbr\u003e* The one-stop premium choice for UOTANG bookshelf speakers\u003cbr\u003e\u003cbr\u003eDeeper and Steadier Pure Bass\u003cbr\u003e* The UOTANG T803 is equipped with a large-diameter 200mm 8-inch pure woofer unit. Its cone is crafted from lightweight, high-strength German 12K carbon fiber material. The lightweight carbon fiber diaphragm delivers fast and crisp low-frequency response, coated with a high-damping layer and fitted with an oversized 50mm large voice coil. It adopts a brand-new wave-shaped ridged surround technology integrally formed with thermoplastic elastic material, paired with an integrated die-cast aluminum-magnesium frame and fully symmetric low-distortion magnetic circuit system. These components endow the T803 with powerful dynamic regeneration and low-frequency control capability, achieving superior linear performance with high clarity and low distortion. You can immediately perceive the bold and steady sound signature of the T803 from the first listen.\u003cbr\u003e* The T803 produces solid, full bass that carries weight without sounding muffled, free of bloated or blurred sound characteristics. It delivers rich, clear and smooth sound, an irreplaceable advantage brought by its core base material. As both mid-range and woofer diaphragms adopt carbon fiber substrates, they maintain highly consistent tonal characteristics with well-balanced sound performance. During playback, listeners will barely detect tonal discrepancies across different frequency bands. For vocal performances, human voices carry richer and more pleasant texture, while upper-mid frequencies also retain ample sound thickness. This stands as a prominent, hard-to-replicate tonal highlight of the T803.\u003cbr\u003e\u003cbr\u003ePure Mid-range with Superior Authenticity\u003cbr\u003e* The UOTANG T803 is fitted with a large-diameter 100mm 4-inch pure mid-range unit, whose cone uses lightweight, high-strength German 12K carbon fiber material. The diaphragm surface is coated with a high-damping layer to drastically cut resonant frequency, and an integrated die-cast aluminum-magnesium frame further suppresses resonance to purify sound quality. These dual measures minimize resonance to the greatest extent, enabling snappy, precise movement of the diaphragm with every vibration. The underlying carbon fiber substrate boosts the T803's sound response speed and purity, rendering mid-range tones clearer and fuller with remarkably refined, concentrated sound and enhanced layering. The mid-range of the T803 delivers highly authentic sound, seamlessly bridging the tweeter and woofer units to produce a full, natural frequency spectrum.\u003cbr\u003e\u003cbr\u003ePure Treble with Superior Purity\u003cbr\u003e* The UOTANG T803 features a 30mm silk dome tweeter unit. Its dome shape meets sufficient rigidity requirements for the diaphragm, while customized damping glue greatly elevates the damping coefficient and drastically reduces resonance interference for cleaner, more precise and transparent treble. The design philosophy of the T803 tweeter diaphragm differs entirely from conventional rigid diaphragms, which strive to eliminate cone break-up distortion. Instead, the T803 leverages the properties of cone break-up distortion: whenever the diaphragm generates a phase distortion, an opposite-phase distortion counteracts it, similar to the interdependence of yin and yang. The sum of all these distortions results in consistent phase sound radiation. Matched with high-quality magnetic fluid, it further reduces phase distortion and sustains orderly, consistent sound output at all times.\u003cbr\u003e* The T803 tweeter features a gentle high-frequency roll-off slope, sounding far more natural than rigid diaphragms with steep high-frequency roll-off curves. It renders treble agile and relaxed with outstanding natural expressiveness, excelling at reproducing standard audio reference music. Percussion instruments are rendered without harshness, supported by a wide frequency range and even frequency response.\u003cbr\u003e\u003cbr\u003eGerman 12K Ultra-Light High-Strength Carbon Fiber with Higher Rigidity, Ultra-Light Weight, High Damping\u003cbr\u003e* The mid-range and woofer diaphragms of the T803 adopt lightweight high-strength German carbon fiber substrate with a high-rigidity plain weave structure. Under precise temperature and pressure control, high molecular polymer is evenly dissolved and coated onto the lightweight carbon fiber substrate, retaining the plain weave structure of the carbon fiber. This enables resonant energy of the diaphragm to disperse uniformly across every carbon fiber thread. Further soaked with customized high-damping coating from UOTANG, damping performance is optimized and enhanced to reach an ideal damping state. Consistent damping characteristics are generated for sound wave energy across frequency bands, achieving the perfect condition of linear resonance dissipation. The mid-range and woofer diaphragms of T803 integrate three merits: sturdiness, light weight and high damping. By leveraging these three properties, the diaphragm performance of T803 is elevated to an entirely new standard, serving as the stable foundation for its transparent and boundless sound presentation.\u003cbr\u003e* The carbon fiber material used in the T803 reduces diaphragm weight while boosting rigidity and strength. Compared with traditional diaphragm materials, it delivers superior physical advantages combining high rigidity and controllable nonlinear distortion. It is remarkably lightweight with excellent damping characteristics for ultra-fast transient response, reproducing crisp and natural sound.\u003cbr\u003e* Carbon fiber diaphragms are generally divided into three weave types: plain weave, twill weave and satin weave. Plain weave carbon fiber diaphragms feature numerous interweaving intersections, making the fabric firm, stiff, flat, thin and uniform with identical surface texture on both sides. It is the optimal weave pattern with maximum rigidity.\u003cbr\u003e\u003cbr\u003eUOTANG Wave-Shaped Ridged Surround Technology Boosts Frequency Response, Reduces Distortion and Delivers Clearer Sound\u003cbr\u003e* The T803 is equipped with UOTANG's all-new copyrighted Wave-Shaped Ridged Surround Technology. The special wave-shaped surround is integrally molded from thermoplastic elastic material, forming an optimized physical structure for sound wave diffusion that allows the diaphragm to perform large-amplitude piston motion. This expands the sound pressure output space for mid and low frequencies, generating powerful, clean and rapid frequency reproduction. During piston movement, the diaphragm operates with greater flexibility and freedom to lift mid and low frequency response while minimizing micro-frequency distortion. Combined with the three core advantages of carbon fiber diaphragms, the T803 delivers steady and powerful mid\/bass performance with clean, crisp sound that carries weight without sounding muffled. Free of any veil-like haze, it produces rich, resonant sound the instant it plays, delivering distinct and solid audio texture.\u003cbr\u003e* The wave-shaped ridged surround of the T803 connects the diaphragm and frame. On one hand, it must enable the diaphragm to conduct free and flexible piston motion; on the other hand, it needs to provide appropriate damping for precise and stable piston travel. Most crucially, the surround must absorb break-up resonance of the diaphragm without introducing deformation distortion during piston movement, which would otherwise interfere with sound wave diffusion. The semi-circular outward convex surround is the most common form, yet prone to deformation distortion under long-stroke movement.\u003cbr\u003e* UOTANG Wave-Shaped Ridged Surround Technology greatly extends stroke length to improve low-frequency response. More importantly, it drastically cuts deformation distortion during surround motion and prevents resonant energy of the diaphragm from bouncing back via the surround to create interference, resulting in far clearer sound.\u003cbr\u003e\u003cbr\u003eBalanced and Stable Linear Piston Motion and DuPont Fiber Mid-range\/Woofer Surround\u003cbr\u003e* The surround and suspension of the T803 jointly support the carbon fiber diaphragm and voice coil assembly. Since they are made of different materials, like two springs with different elasticity pulling the same object, maintaining a stable and balanced piston motion state is highly challenging. The T803 uses a DuPont fiber surround, which is designed to approximate the wave-shaped surround in terms of damping, stiffness and compliance characteristics. This helps keep the tensile force, damping properties and compliance characteristics consistent when the carbon fiber diaphragm moves. At the same time, the two are assembled with a relatively long distance between them to ensure more stable movement, allowing the mid\/bass units in the T803 to reach a stable linear piston motion state. This is also an internal detail that contributes to the more transparent sound of the T803, delivering clear and distinguishable audio texture.\u003cbr\u003e\u003cbr\u003eIntegrated Die-Cast Aluminum-Magnesium Frame Effectively Suppresses Resonance, with Lower Coloration\u003cbr\u003e* The T803 adopts an integrated die-cast aluminum-magnesium frame, which is structurally rigid and less prone to resonance. This significantly reduces the coloration caused by frame resonance on the loudspeaker output. At the same time, aluminum-magnesium alloy is an excellent thermal conductor. The aluminum-magnesium frame is directly attached to the diaphragm, quickly dissipating the heat generated by the voice coil and magnetic circuit system. The greater the power it can handle, the stronger the dynamic capability of the T803.\u003cbr\u003e\u003cbr\u003ePremium Raw Materials, Exceptional Craft Texture\u003cbr\u003e* The cabinet of T803 is constructed from Finnish birch plywood bonded via cross-lamination under high temperature and high pressure. Its internal layers are evenly distributed, delivering high density, high structural strength and excellent damping performance. With a solid 15mm panel thickness paired with superior damping characteristics, it drastically suppresses cabinet resonance and standing waves to minimize sonic coloration. The entire cabinet surface is veneered with imported Brazilian solid wood, showcasing authentic natural timber grain with perfectly balanced tone, brightness and texture.\u003cbr\u003e\u003cbr\u003eMore Details\u003cbr\u003e* High-end mid-tone gray color scheme\u003cbr\u003e* Finnish birch plywood\/Brazilian solid wood veneer\u003cbr\u003e\u003cbr\u003eBuilt on Acoustic Standards, Yet Surpassing Them All and Delivering Scientific, Natural Sound to Your Ears\u003cbr\u003e* The full acoustic design undergoes testing with the LMS electro-acoustic system from American LinearxSystem, alongside analysis and simulation via American LEAP electro-acoustic software. After repeated calibration, testing and listening evaluation by golden-ear audio experts, both electro-acoustic instruments and human hearing are leveraged to pursue optimal sound quality, making the acoustic performance of the T803 more scientific and well-balanced.\u003cbr\u003e\u003cbr\u003eBi-Wire Connection Supported and Solid Copper Gold-Plated Binding Posts\u003cbr\u003e* When the two groups of binding posts are linked with copper jumpers, only one pair of speaker cables is required to connect to the power amplifier, which is the standard wiring method. The connecting jumpers are made of pure red copper to guarantee reliable signal transmission. When the copper jumpers are removed to disconnect the two sets of binding posts, each speaker needs two pairs of cables connected to the power amplifier, which must support bi-wire mode. The bi-wire technology separates high-midrange and bass signal transmission paths, effectively suppressing intermodulation distortion common in most loudspeakers.\u003cbr\u003e\u003cbr\u003eAsymmetric Horn-Shaped Port Tube and Minimum Phase System Crossover\u003cbr\u003e* UOTANG T803 has passed enclosure tests with port tubes of multiple profiles, finally adopting an asymmetric horn-shaped port tube with 110mm outer diameter and 85mm inner diameter. It features asymmetric inner and outer openings with a smaller radius at the inner end and a larger radius at the outer end. The total depth of 155mm strikes an optimal balance between distortion reduction and dynamic compression control. The T803 equips a minimum phase system crossover that eliminates overshoot and reverse overshoot, delivering fast transient response and minimal energy accumulation.\u003cbr\u003e\u003cbr\u003eHook-and-Loop Grille Without Cabinet Drilling Holes\u003cbr\u003e* The T803 adopts a finely woven sound-transparent grille made of polyester fiber, featuring great wrinkle resistance and shape retention, along with high tensile strength and elastic recovery capacity. It is designed with heavy-duty hook-and-loop fasteners on four corners, eliminating the need to drill holes on the cabinet. This reduces rigid contact between the grille and cabinet to suppress resonance. The premium neutral medium-gray tone delivers a mild, elegant and refined look that blends harmoniously with various interior environments. The cross-shaped fine weave of polyester fiber creates uniform subtle grain texture, instantly upgrading the product grade.\u003cbr\u003e\u003cbr\u003eShock-Isolating Damping Spikes Included\u003cbr\u003e* The T803 is equipped with high-quality professional-grade spikes that realize equipment vibration damping without distorting sound tuning. Made of solid aluminum alloy and copper with high-density non-slip rubber pads, they deliver outstanding transient response. Featuring an independent suspended internal structure and active floating design, they support adaptive fine height adjustment from 1mm to 3mm. They counteract feedback vibration on speakers caused by airborne sound waves, eliminating interference from mechanical resonance.\u003cbr\u003e* Top Tray Diameter: 38mm\u003cbr\u003e* Base Diameter: 45mm\u003cbr\u003e* Overall Height: 32mm\u003cbr\u003e\u003cb\u003e\u003cbr\u003e2. Specifications:\u003c\/b\u003e\u003cbr\u003e* Dimension: 270mm (W) x 480mm (H) x 365mm (D) (excluding binding posts)\u003cbr\u003e* Recommended Amplifier Models: UOTANG MK8900\/MK8806\/MK9200 + MK9600\u003cbr\u003e* Sensitivity: 90dB\u003cbr\u003e* Impedance: 8Ω\u003cbr\u003e* Power Handling: 20W-200W\u003cbr\u003e* Frequency Response: 30Hz-30KHz\u003cbr\u003e* Weight: 30KG per pair (2 speakers)\u003cbr\u003e* Color: Natural Wood Finish\u003cbr\u003e* Bass Unit: 200mm 8-inch Carbon Fiber Woofer Unit\u003cbr\u003e* Mid-range Unit: 100mm 4-inch Carbon Fiber Mid-range Unit\u003cbr\u003e* Treble Unit: 30mm Silk Soft Dome Tweeter Unit\u003cbr\u003e\u003cb\u003e\u003cbr\u003e\u003cspan style=\"background-color: rgb(255, 255, 0);\"\u003eMK9000 Tube Amp:\u003c\/span\u003e\u003cbr\u003e1. Description:\u003c\/b\u003e\u003cbr\u003eUOTANG MK9000 adheres to the traditional essence of tube amplifiers while integrating UOTANG's innovative modern circuit design philosophy. It represents a powerful combination, delivering a modern interpretation of intricate traditional circuits.\u003cbr\u003e\u003cbr\u003eUOTANG MK9000 is a high-power vacuum tube amplifier adopting pure Class A and push-pull topology, which breaks the efficiency limitations of conventional 300B tube amplifiers. It employs rare genuine 300B tubes as output power tubes, operating under a true pure Class A push-pull configuration with 300B tubes serving as transistors. This is the core highlight of the MK9000 and a distinctive feature that sets it apart from similar competing products.\u003cbr\u003e\u003cbr\u003eThe MK9000 retains the tonal warmth of single-ended 300B output while boasting the high efficiency of push-pull architecture, delivering outstanding performance superior to standard benchmarks in dynamics, damping factor and resolution. While inheriting the core merits of classic tube amplifiers, the MK9000 incorporates UOTANG's cutting-edge modern circuit design. Centered on pure Class A push-pull framework, direct-coupled long-tailed phase inverter and zero negative feedback design, it is equipped with RCA 6GH8A, 17BE3 and UOTANG custom 300B vacuum tubes. It restores the mellow timbre of direct-heated cathode 300B tubes. The push-pull circuit ensures symmetrical driving and balanced phase response, and the zero negative feedback topology preserves rich harmonic overtones. The MK9000 tube amplifier lets you perceive the vivid vitality and warm texture of sound.\u003cbr\u003e\u003cbr\u003eThe MK9000 delivers remarkable design and performance across all core technical aspects. It features direct-coupled long-tailed phase inverter design, zero negative feedback circuit, triple purification via CLC filter, full-range interface compatibility, pure power amplifier mode, freely switchable dual NFB modes, dual independent wide-frequency output transformers, cathode follower circuit, full-wave tube rectification, tempered glass front panel and full automotive-grade baking varnish body finish.\u003cbr\u003e\u003cbr\u003e\u003cb\u003e2. Features:\u003c\/b\u003e\u003cbr\u003eUOTANG MK9000 Pure Class A Push-Pull 300B Large Tube Amplifier\u003cbr\u003e* Floor-standing and Bookshelf Speakers Driven Effortlessly\u003cbr\u003e* Pure Class A Tube Amplifier\u003cbr\u003e* 300B x 4 Push-Pull Output\u003cbr\u003e* Direct-Coupled Long-Tailed Phase Inverter Design\u003cbr\u003e* Zero Negative Feedback Design\u003cbr\u003e* Full-Wave Tube Rectification\u003cbr\u003e* Triple Purification with CLC Filter Circuit\u003cbr\u003e* 11 Brand Vacuum Tubes Installed\u003cbr\u003e* High-Power EI-Type Transformer Power Supply\u003cbr\u003e* Dual NFB Mode Switching\u003cbr\u003e* Large Screen Dual Meters\u003cbr\u003e* Can Be Used As Pure Power Amplifier\u003cbr\u003e* Comprehensive Interface Configuration\u003cbr\u003e* Hand-Wound Chassis Plus PCB Circuit Board\u003cbr\u003e* Tempered Glass Panel with Baking Varnish Finish\u003cbr\u003e\u003cbr\u003eCombines Distinctive Timbre Characteristics with High Efficiency\u003cbr\u003e* Pure Class A Tube Amplifier\u003cbr\u003e* Direct-Coupled Long-Tailed Phase Inverter Design\u003cbr\u003e* 300B × 4 Push-Pull Output\u003cbr\u003e* Zero Negative Feedback Design\u003cbr\u003e\u003cbr\u003ePure Class A Push-Pull Vacuum Tube Amplifier\u003cbr\u003e* We developed the MK9000 with extremely high technical barriers, a tube amplifier with nearly no equivalent counterparts. It breaks the existing technical bottlenecks for audiophiles who favor authentic tube sound, daring to adopt 300B tubes for pure Class A push-pull operation.\u003cbr\u003e* The MK9000 is a genuine pure Class A push-pull tube amplifier utilizing 300B tubes as output power valves.\u003cbr\u003e\u003cbr\u003eGenuine High-Power Push-Pull Output with Four 300B Tubes\u003cbr\u003e* It subverts the mainstream market norm where 300B tubes only act as driver stages and indirectly compromise sound quality. The MK9000 fully unlocks the linear amplification performance of direct-heated triodes, fundamentally refusing to compromise or distort the original acoustic properties of 300B tubes. The core output section of the MK9000 adopts UOTANG-branded 300B vacuum tubes to form a pure Class A push-pull output circuit. The push-pull structure counteracts even-order harmonic distortion while retaining the unique second-order harmonic overtones exclusive to UOTANG MK9000's 300B tubes. Its linear performance, even-order harmonic characteristics and rich mid-range saturation are fully delivered in the final audio output. Especially within this highly technically demanding Class A push-pull design, its warm, delicate classic tube timbre is maximized.\u003cbr\u003e\u003cbr\u003eSilent Guardian of High Fidelity: Direct-Coupled Long-Tailed Phase Inverter Design\u003cbr\u003e* The MK9000 adopts the direct-coupled long-tailed phase inverter circuit as the phase controller of its push-pull architecture, converting single-ended input signals into symmetric and balanced positive and negative half-cycle drive signals. Adopting the optimal combination of DC coupling and long-tailed bias configuration, it builds an accurate and solid signal foundation for the 300B push-pull output of the MK9000. The direct-coupled long-tailed phase inverter design of the MK9000 achieves perfect synergy with its pure Class A push-pull architecture. The MK9000 not only resolves the inherent flaws of traditional 300B phase inverter circuits, but also fully unlocks the musicality of 300B tubes, embodying both sophisticated technology and relentless pursuit of premium sound.\u003cbr\u003e\u003cbr\u003eZero Negative Feedback Design\u003cbr\u003e* The UOTANG MK9000 features full-band zero negative feedback design. There is no feedback loop routed back from the output stage within the signal path from the input stage to the power stage. This design fully preserves the noble and authentic timbre of the MK9000's 300B vacuum tubes.\u003cbr\u003e* Fully retain the genuine warm timbre of authentic 300B tubes, delicate instrument decay harmonics, and vocal breath details.\u003cbr\u003e* Conventional negative feedback circuits compress dynamic fluctuations of sound, while zero negative feedback imposes no such restriction and delivers an expansive dynamic range.\u003cbr\u003e* Zero negative feedback demands far stricter component quality standards. Paired with a large power transformer and multi-stage filtering, it achieves an ultra-quiet noise floor.\u003cbr\u003e* The streamlined zero negative feedback circuit eliminates blocking capacitors and adopts direct coupling, delivering an extended frequency response range.\u003cbr\u003e\u003cbr\u003eDirect Coupling Circuit Design with High-Fidelity Pre-processing for Pure Signals\u003cbr\u003e* The input stage of the MK9000 utilizes the triode section of vintage American RCA 6GH8A tubes. Equipped with a common-cathode amplifier circuit, the direct-coupled design removes coupling capacitors and introduces signals directly. It maintains the continuity of DC bias configuration, freeing the low-frequency response of the MK9000 from capacitor limitations. This endows the MK9000 with outstanding ultra-low frequency extension capability.\u003cbr\u003e\u003cbr\u003eCathode Follower Circuit Design Preserves Transient Signal Details\u003cbr\u003e* Integrated cathode follower circuitry ensures stable signal transmission across the multi-stage amplification system. The MK9000 leverages the triode segment of the 6GH8A tube to construct the cathode follower circuit. It buffers the impedance mismatch between the high-impedance preamplifier stage and the rear load, enabling clean signal transmission for the MK9000. It safeguards subtle transient details and dynamic information within audio signals.\u003cbr\u003e\u003cbr\u003eDual Hybrid Full-Wave Rectification: Superimposed Secondary Tube Timbre\u003cbr\u003e* The UOTANG MK9000 adopts high-voltage transistor full-wave rectification followed by secondary rectification via 17BE3 vacuum tubes. This design preserves dynamic response while enriching tonal charm and lowering ripple fundamental noise at the source. Its dynamic response aligns closely with the current characteristics of 300B tubes, maintaining the operating point of 300B tubes within the linear amplification region for more natural vocal density and instrumental texture. Meanwhile, the second harmonics naturally generated during the MK9000 rectification process overlap with the even-order harmonics of 300B tubes, adding authentic analog warmth reminiscent of the vinyl era tube sound.\u003cbr\u003e\u003cbr\u003eTriple Signal Purification via CLC Filter Restores Silent Background and Reveal Subtle Faint Audio Details\u003cbr\u003e* The first stage capacitor C1 of the MK9000 quickly absorbs high-frequency noise with premium-grade capacitance components. The middle inductor L is a choke coil that stores magnetic energy through electromagnetic induction. It continuously delivers stable current during large dynamic peaks to strengthen low-frequency extension and control. When handling small signals, the inductor's internal resistance rises automatically as current diminishes, eliminating low-frequency hum caused by reverse current and enabling smoother, more natural dynamic transitions for the MK9000. The final stage capacitor C2 precisely filters residual ripples to reduce hum interference. The combination of 17BE3 full-wave rectification and CLC filter is not a simple stack of components; it represents in-depth optimization tailored for the acoustic properties of 300B tubes. It delivers lower noise, more linear response, and more musical power supply characteristics to create an ideal operating environment for the MK9000's 300B tubes. True premium sound relies on every power cycle of the power supply resonating synchronously with music.\u003cbr\u003e\u003cbr\u003eWide-Band Lossless Transmission Architecture\u003cbr\u003e* A high-power EI-type power transformer custom-engineered exclusively for the 300B tubes of the MK9000. It adopts Class A iron core isolation transformers wound with 180°C heat-resistant QZY polyester imide enameled wire. The premium isolated transformer effectively eases current surges and enhances low-frequency bounce control performance.\u003cbr\u003e\u003cbr\u003eGroundbreaking Choice for Acoustic Performance and Design\u003cbr\u003e* Preamp Voltage Amplifier \u0026amp; Phase Inverter Driver Tubes: 6 Imported Vintage 6GH8A Tubes. Six genuine vintage American RCA 6GH8A vacuum tubes are selected, featuring an independent cathode design. They support differential amplification and phase splitting functions to effectively suppress noise interference, and inject moderate second harmonics during amplification to deliver non-linear tonal embellishment to audio signals.\u003cbr\u003e* 17BE3 Rectifier Tubes: Vintage American RCA 17BE3 tubes are deployed for tube-type rectification and overload protection. The independent dual high-voltage circuit cuts power consumption of vacuum tubes and further boosts overall tube timbre. The 17BE3 delivers powerful analytical capability with neutral, straightforward sound characteristics, reproducing more authentic and natural timbre.\u003cbr\u003e* Output Power Amplifier Tubes: 4 Custom UOTANG 300B Tubes. Custom UOTANG 300B tubes power the Class A push-pull amplification paired with direct-coupled long-tailed phase inverter circuit design. It retains the linear advantages of Class A topology and offsets even-order harmonics via symmetrical structure, striking an optimal balance between pristine clarity and powerful output. It delivers delicate, mellow sound that preserves the noble inherent character of 300B tubes, with more controllable explosive power than single-ended designs, achieving an exquisite balance of high fidelity and rich tonal charm.\u003cbr\u003e\u003cbr\u003eAdjustable NFB Negative Feedback Technology\u003cbr\u003e* The UOTANG MK9000 supports free switching between two NFB modes, unlocking two completely distinct musical signatures via 0dB and -3dB settings to help you discover your exclusive sonic aesthetic.\u003cbr\u003e* -3dB Mode (Gear 1): Refined, Balanced \u0026amp; Exquisite. Moderate negative feedback is introduced to precisely optimize the frequency response curve, delivering smoother, well-structured sound with soft, pure and mellow tonal characteristics, ideal for vocal, string and similar music genres.\u003cbr\u003e* 0dB Mode (Gear 2): Pure Original Sound, Full Dynamic Range. Negative feedback is completely bypassed to faithfully restore the original harmonic characteristics of vacuum tubes, presenting open, bold and powerful sound that suits music with grand dynamic scenes.\u003cbr\u003e\u003cbr\u003eFull-Width Panel, Dual Meters, Dual Functions\u003cbr\u003e* Real-time operating status monitoring at a glance\u003cbr\u003e* Precise fixed bias adjustment\u003cbr\u003e* The MK9000 is equipped with high-precision dual-function stereo UV audio level meters. The meters monitor operating conditions and support bias adjustment, enabling intuitive observation of tube working status and convenient fixed bias tuning.\u003cbr\u003e* Independent external BIAS ADJ controls allow effortless monitoring and fine-tuning of operating parameters.\u003cbr\u003e* The full-width integrated meter panel delivers immersive visual feedback linked to audio details, paired with a black background and soft warm white backlight to convey understated premium texture.\u003cbr\u003e\u003cbr\u003eDual Modes: Power Amp Only\/Integrated Amplifier\u003cbr\u003e* The UOTANG MK9000 can operate as a standalone power amplifier, with dual modes balancing ease of use and advanced customization.\u003cbr\u003e* Power Amp Only Mode: Directly connect an independent preamplifier via the Pre In port, compatible with both tube and solid-state preamps. Its 2000mV high-sensitivity input works with 99% of preamplifiers on the market.\u003cbr\u003e* Integrated Amplifier Mode: Directly connect audio sources via dual RCA inputs, balanced inputs and turntable inputs, with a 420mV sensitivity plug-and-play design.\u003cbr\u003e\u003cbr\u003eFull-Compatible Interface Design: Adaptable to Diverse Audio Sources\u003cbr\u003e* The MK9000 is equipped with three major input ports: turntable input, dual RCA inputs and balanced inputs. It delivers universal compatibility covering analog audio sources, digital playback devices, home audio systems and professional setups, unlocking premium sound performance for every audio medium.\u003cbr\u003e* Turntable Input: The dedicated PHONO port is custom-built for analog LP turntables to restore the mellow texture of vinyl records. Its exclusive MM input features a precise 51kΩ impedance matching the output characteristics of moving magnet cartridges to eliminate load distortion, fully preserving the micro groove details and analog warmth of vinyl records.\u003cbr\u003e* Dual RCA Inputs: Two groups of CD \u0026amp; AUX dual RCA ports support 99% of mainstream home audio devices including CD players, audio decoders and streaming players. With a 420mV input sensitivity, it offers plug-and-play operation without complicated setup.\u003cbr\u003e* Full Balanced XLR Input: The balanced port adopts a 3-pin XLR structure that transmits differential positive and negative signals to effectively filter electromagnetic interference during signal transmission.\u003cbr\u003e\u003cbr\u003eHand-Wired Chassis for Large Signals + PCB for Small Signals\u003cbr\u003e* The MK9000 combines hand-wired point-to-point construction for high-current large-signal paths with printed circuit boards for delicate small-signal circuits. Custom-tuned for distinct signal properties, this design strikes a balance between anti-interference stability and pure signal integrity, ensuring long-term reliable operation and high-fidelity audio reproduction.\u003cbr\u003e* Large Signal Hand-Wired Chassis: High-current circuits such as power amplification stages and power supply rectification \u0026amp; filtering adopt hand-wired wiring to guarantee stable large-current transmission.\u003cbr\u003e* Small Signal PCB Soldering: Pre-amplification, phase inverter circuits and control modules are laid out on PCBs with optimized signal traces to avoid electromagnetic interference from high-current circuits to delicate small signals.\u003cbr\u003e\u003cbr\u003ePower-On Delay Warm-Up Protection\u003cbr\u003e* The UOTANG MK9000 features a built-in warm-up system with approximately 30 seconds of mute after power-on. Integrated power-on delay protection and mute delay protection deliver shock-free power-up timing. Low voltage heats the tube filaments first with high voltage delayed, while low current pre-charges capacitors for energy storage. High voltage ramps up gradually to full level before audio output, enabling sufficient warm-up for all vacuum tubes.\u003cbr\u003e\u003cbr\u003eElegant and Refined Timbre\u003cbr\u003e* It delivers the poised sonic demeanor inherent to pure Class A circuits and the technical advantages brought by direct-coupled architecture. A highly symmetrical differential phase inverter circuit constructs an accurate stereo soundstage with striking dynamic impact. Human vocals sound warm, intimate and uncolored, balancing rich density and natural breathing texture. Dynamic range is reproduced authentically to deliver studio-grade immersive live sound experience.\u003cbr\u003e\u003cbr\u003eRecommended Matching UOTANG Speakers\u003cbr\u003e* T806\u003cbr\u003e* T803\u003cbr\u003e* T602\u003cbr\u003e* T605\u003cbr\u003e\u003cbr\u003e\u003cb\u003e3. More Details:\u003c\/b\u003e\u003cbr\u003e* Premium Texture from Automotive-Grade Body Painting Craft\u003cbr\u003e* Tempered Glass Front Panel Creates Dazzling Visual Echo with Vacuum Tubes\u003cbr\u003e* Pure Aluminum Alloy Infrared Remote Controller with Exquisite Matte Natural Texture: The MK9000 is equipped with a premium metal remote controller for audio volume adjustment.\u003cbr\u003e* Japan ALPS Motorized Potentiometer with High Precision, Low Sonic Contamination: It guarantees balanced sound output between left and right channels, featuring superior linear precision and minimal dynamic noise.\u003cbr\u003e* Independent Audio Relays for Omni-Directional Targeted Protection: Three groups of audio inputs are each fitted with an independent relay, delivering separate protection for every input channel.\u003cbr\u003e* Independent Output Relays Provide Separate Dual-Channel Protection: Each channel is protected by an individual relay, plus an extra grounding relay for the earth wire.\u003cbr\u003e* True Balanced Audio Input Ports Satisfy Demands for Finer Audio Details: It is equipped with XLR balanced audio input jacks to reproduce richer sonic micro-details.\u003cbr\u003e* Spherical Anti-Vibration Feet for Superior Shock Isolation: The MK9000 adopts custom spherical shock-absorbing foot pads for outstanding vibration suppression performance.\u003cbr\u003e* Pure Copper Gold-Plated Terminals for Efficient \u0026amp; Stable Signal Transmission: Low output internal resistance delivers excellent signal conductivity, effectively reducing transmission loss.\u003cbr\u003e* Easy Plug-and-Play Protective Cover with Automotive-Grade Precision Baking Varnish Craftsmanship: Both the main chassis and mesh grille adopt baking varnish finishing, forming an integrated seamless body with a grand visual presence.\u003cbr\u003e* High-Precision Voltage Stabilization Circuit Built with Four Imported Voltage Regulator Tubes: It supplies continuous stable voltage to the entire amplifier unit, delivering rich and powerful low-frequency response, crisp mid-to-high frequencies, and retaining abundant micro-details even under large dynamic swings.\u003cbr\u003e* Premium Imported Brand Capacitors \u0026amp; Japanese 5-Band High-Quality Resistors: It is fitted with German CHIRMCAP audio capacitors, Rubycon, Nichicon and Black Diamond electrolytic \u0026amp; film capacitors that feature high temperature resistance, long service life and low internal resistance.\u003cbr\u003e\u003cb\u003e\u003cbr\u003e4. Specifications:\u003c\/b\u003e\u003cbr\u003e* Product Dimensions: 430mm(W) x 217mm(H) x 385mm(D) (Including Terminal Posts)\u003cbr\u003e* Rated Output Power: 24W + 24W (RMS Operating Condition)\u003cbr\u003e* Total Harmonic Distortion: ≤1% (1kHz)\u003cbr\u003e* Input Sensitivity: 420mV (Integrated Input)\/2000mV (Power Amp Only Input)\u003cbr\u003e* Input Impedance: 100KΩ\u003cbr\u003e* MM Phono Amp Input Impedance: 51KΩ\u003cbr\u003e* MM Phono Amp Voltage Gain: 40dB (1kHz)\u003cbr\u003e* MM Phono Amp RIAA Frequency Response: 0.25dB 20Hz-20KHz\u003cbr\u003e* Output Impedance: 4Ω, 8Ω, 16Ω\u003cbr\u003e* Overall Frequency Response: 18Hz-32kHz (-1.5dB)\u003cbr\u003e* Left\/Right Output Balance: \u0026lt;0.5dB\u003cbr\u003e* Signal-To-Noise Ratio: 89dB\u003cbr\u003e* Total Power Consumption: 280W\u003cbr\u003e* Net Weight: 28KG\u003cbr\u003e* Vacuum Tubes: 6 x 6GH8A, 1 x 17BE3, 4 x 300B\u003cbr\u003e* Power Supply Voltage: 220V ±5% (50Hz)\u003cbr\u003e\u003cbr\u003e\u003cspan style=\"background-color: rgb(255, 255, 0);\"\u003e\u003cb\u003ePacking List (Depending on Selected Configuration):\u003c\/b\u003e\u003c\/span\u003e\u003cbr\u003eT803 Speakers:\u003cbr\u003e* 2 x Speakers\u003cbr\u003e\u003cbr\u003e* T803 Speakers + MK9000 Tube Amp:\u003cbr\u003e* 2 x Speakers\u003cbr\u003e* 1 x Set of Tube Amplifier\u003cbr\u003e\u003cbr\u003e\u003cspan style=\"background-color: rgb(255, 255, 0);\"\u003e\u003cb\u003ePackaging Details (Depending on Selected Configuration):\u003c\/b\u003e\u003c\/span\u003e\u003cbr\u003eT803 Speakers:\u003cbr\u003e* Package weight: 32kg\u003cbr\u003e\u003cbr\u003e* T803 Speakers + MK9000 Tube Amp: \u003cbr\u003e* Package weight: 62kg\u003c\/p\u003e","brand":"UOTANG","offers":[{"title":"T803 Speakers","offer_id":41103571189809,"sku":"103116","price":1831.32,"currency_code":"USD","in_stock":true},{"title":"T803 Speakers + MK9000 Tube Amp","offer_id":41103571222577,"sku":"103117","price":4194.3,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0578\/4790\/6353\/files\/103116-1.jpg?v=1783058201","url":"https:\/\/www.thanksbuyer.com\/ko\/products\/2pcs-uotang-t803-passive-bookshelf-speakers-8-inch-3-way-hifi-home-stereo-speakers-mk9000-tube-amp","provider":"Thanksbuyer Online,SDR Radio, Testers and Measurement devices, Astronomy products,  Audio Amplifer and Decoders","version":"1.0","type":"link"}