{"product_id":"mcintosh-mc901-dual-mono-amplifier","title":"McIntosh MC901 1-Channel Hybrid Drive Dual Mono Power Amplifier","description":"\u003ch2\u003eMcIntosh MC901 Hybrid Drive Dual Mono Amplifier\u003c\/h2\u003e\n\u003cp\u003eThe \u003cstrong\u003eMcIntosh MC901\u003c\/strong\u003e is a one-of-a-kind, 1-channel Hybrid Drive power amplifier created specifically for reference-level bi-amping. Each MC901 combines a \u003cstrong\u003e300-watt vacuum tube amplifier\u003c\/strong\u003e and a \u003cstrong\u003e600-watt solid state amplifier\u003c\/strong\u003e on one unified chassis, allowing the tube section to power a loudspeaker’s midrange and high-frequency drivers while the solid state section controls its woofers.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eThe MC901 is sold individually.\u003c\/strong\u003e One amplifier powers one compatible bi-amp-capable loudspeaker. A conventional stereo system requires two MC901 amplifiers.\u003c\/p\u003e\n\u003ch3\u003eTwo Amplifiers Working as One\u003c\/h3\u003e\n\u003cp\u003eThe MC901 is often described as a Dual Mono amplifier because it contains two fully developed amplification sections with separate power supplies and signal paths. Unlike a stereo amplifier, however, both sections are dedicated to a single loudspeaker:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e300-watt vacuum tube section:\u003c\/strong\u003e Designed for the speaker’s midrange and high-frequency drivers.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-watt solid state section:\u003c\/strong\u003e Designed for the power-hungry woofer section.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eThe vacuum tube amplifier uses eight KT88 output tubes, four 12AT7 tubes and two 12AX7A tubes. McIntosh’s Unity Coupled Circuit output transformer allows the tube section to deliver its full 300 watts into 2-, 4- or 8-ohm loads. The solid state section uses McIntosh Autoformer technology to provide its full 600 watts into 2, 4 or 8 ohms.\u003c\/p\u003e\n\u003cp\u003eThe two ratings are not combined into a conventional 900-watt full-range output. Each amplifier section powers a separate frequency range and must be connected to the appropriate terminals of a compatible bi-amp-capable loudspeaker.\u003c\/p\u003e\n\u003ch3\u003eIntegrated Adjustable Crossover\u003c\/h3\u003e\n\u003cp\u003eTraditional bi-amping typically requires two separate amplifiers, an external crossover and careful level matching. The MC901 brings those functions together in one purpose-built chassis. Adjustable high-pass and low-pass filters are located on the top rear of the amplifier, making it possible to optimize the transition between the tube and solid state sections for the connected loudspeaker.\u003c\/p\u003e\n\u003cp\u003eRelative gain for each amplifier section can be adjusted from \u003cstrong\u003e-6dB to +3dB\u003c\/strong\u003e. Separate direct inputs also allow the internal filters to be bypassed when an external active crossover or loudspeaker-management system is being used.\u003c\/p\u003e\n\u003ch3\u003eHybrid Drive Sound and Control\u003c\/h3\u003e\n\u003cp\u003eMcIntosh Hybrid Drive technology is intended to combine the characteristics of vacuum tube amplification with the control and current delivery of a high-power solid state amplifier. The tube section is relieved of deep-bass reproduction and can concentrate on the midrange and treble, while the 600-watt solid state section supplies the damping and power required for demanding woofers.\u003c\/p\u003e\n\u003cp\u003eEach section has its own discrete power supply, so neither amplifier draws operating reserves from the other. This arrangement allows both sections to perform as dedicated amplifiers rather than as two outputs sharing a compromised power supply.\u003c\/p\u003e\n\u003ch3\u003eDualView Power Output Meter\u003c\/h3\u003e\n\u003cp\u003eThe MC901 introduced McIntosh’s DualView power-output meter. Two fast-responding mechanical meters are stacked in a single illuminated window:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eThe upper meter displays the output of the 300-watt vacuum tube amplifier.\u003c\/li\u003e\n\u003cli\u003eThe lower meter displays the output of the 600-watt solid state amplifier.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eBoth sections can therefore be monitored independently while retaining the signature blue McIntosh meter presentation.\u003c\/p\u003e\n\u003ch3\u003eMcIntosh Protection Technologies\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePower Guard®:\u003c\/strong\u003e Monitors the solid state section and helps prevent harsh clipping and potential loudspeaker damage.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePower Guard Screen Grid Sensor™:\u003c\/strong\u003e Monitors screen-grid current in the KT88 output tubes and dynamically reduces the input signal when necessary to help protect tube life.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSentry Monitor™:\u003c\/strong\u003e Protects the amplifier against unsafe output-current conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eQuad Balanced solid state design:\u003c\/strong\u003e Helps cancel noise and distortion within the signal path.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePower Control:\u003c\/strong\u003e Coordinates startup and shutdown with compatible McIntosh components.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePower Management:\u003c\/strong\u003e Can switch the amplifier off after a selected period without an input signal.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eFlexible Input Configuration\u003c\/h3\u003e\n\u003cp\u003eThe MC901 provides composite inputs that feed both amplifier sections through the internal crossover, along with direct inputs for the vacuum tube and solid state sections. Balanced connections allow it to integrate with reference preamplifiers and active crossover systems while maintaining separate signal paths when required.\u003c\/p\u003e\n\u003cp\u003eA natural system partner is the \u003ca href=\"\/products\/mcintosh-c12000-2-channel-solid-state-and-vacuum-tube-preamplifier\"\u003eMcIntosh C12000 Preamplifier\u003c\/a\u003e, which provides balanced outputs and selectable tube or solid state operation for a complete reference-level McIntosh system.\u003c\/p\u003e\n\u003ch3\u003eMC901 vs. MC451\u003c\/h3\u003e\n\u003cp\u003eThe \u003ca href=\"\/products\/mcintosh-mc451-1-channel-dual-mono-amplifier\"\u003eMcIntosh MC451\u003c\/a\u003e uses the same basic Hybrid Drive concept in a smaller and lighter design. The MC451 provides 150 watts of tube power and 300 watts of solid state power, while the MC901 doubles those ratings to 300 and 600 watts. The MC901 also uses a larger Quad Balanced solid state section and is intended for the most demanding loudspeakers, larger rooms and systems requiring substantial low-frequency control.\u003c\/p\u003e\n\u003cp\u003eThe MC451 is generally the more practical option where its lower output is sufficient. The MC901 is the statement choice for loudspeakers that can take advantage of its power, scale and independently optimized tube and solid state sections.\u003c\/p\u003e\n\u003ch3\u003eInstallation and Loudspeaker Requirements\u003c\/h3\u003e\n\u003cp\u003eThe MC901 should only be used with loudspeakers designed for bi-wiring or bi-amping, with electrically separate low-frequency and mid\/high-frequency input terminals. Any factory jumpers between those terminal sections must be removed before connecting the separate MC901 outputs. The tube and solid state outputs must never be tied together.\u003c\/p\u003e\n\u003cp\u003eAt approximately \u003cstrong\u003e180 pounds\u003c\/strong\u003e and nearly 30 inches deep, each amplifier requires substantial equipment support, ventilation and access for the top-mounted crossover controls. A stereo pair weighs approximately 360 pounds before packaging, so floor loading, rack or platform capacity, delivery access and electrical requirements should be planned before installation.\u003c\/p\u003e\n\u003ch3\u003eMcIntosh MC901 Specifications\u003c\/h3\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eAmplifier Type\u003c\/th\u003e\n\u003ctd\u003e1-channel Hybrid Drive dual-amplifier monoblock\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eVacuum Tube Output\u003c\/th\u003e\n\u003ctd\u003e300 watts into 2, 4 or 8 ohms\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eSolid State Output\u003c\/th\u003e\n\u003ctd\u003e600 watts into 2, 4 or 8 ohms\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eNumber of Channels\u003c\/th\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eVacuum Tubes\u003c\/th\u003e\n\u003ctd\u003e8 KT88, 4 12AT7 and 2 12AX7A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eSolid State Circuit Configuration\u003c\/th\u003e\n\u003ctd\u003eQuad Balanced\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eVacuum Tube Circuit Configuration\u003c\/th\u003e\n\u003ctd\u003eUnity Coupled\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eSolid State Output Type\u003c\/th\u003e\n\u003ctd\u003eAutoformer™\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eVacuum Tube Output Type\u003c\/th\u003e\n\u003ctd\u003eUnity Coupled Circuit output transformer\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eTotal Harmonic Distortion\u003c\/th\u003e\n\u003ctd\u003eSolid state: 0.005%; vacuum tube: 0.5%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eSignal-to-Noise Ratio\u003c\/th\u003e\n\u003ctd\u003eSolid state: 122dB; vacuum tube: 112dB\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eDynamic Headroom\u003c\/th\u003e\n\u003ctd\u003eSolid state: 2.5dB; vacuum tube: 1.2dB\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eDamping Factor\u003c\/th\u003e\n\u003ctd\u003eSolid state: greater than 40; vacuum tube: greater than 18\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eRated Power Band\u003c\/th\u003e\n\u003ctd\u003e20Hz to 20kHz for both sections\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eSolid State Frequency Response\u003c\/th\u003e\n\u003ctd\u003e+0\/-0.25dB from 20Hz to 20kHz; +0\/-3dB from 10Hz to 100kHz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eVacuum Tube Frequency Response\u003c\/th\u003e\n\u003ctd\u003e+0\/-0.5dB from 20Hz to 20kHz; +0\/-3dB from 10Hz to 70kHz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eCrossover\u003c\/th\u003e\n\u003ctd\u003eAdjustable high-pass and low-pass filters with direct-input bypass\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eRelative Level Adjustment\u003c\/th\u003e\n\u003ctd\u003e-6dB to +3dB for each amplifier section\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eBalanced Inputs\u003c\/th\u003e\n\u003ctd\u003e3: solid state direct, vacuum tube direct and composite\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eSpeaker Connections\u003c\/th\u003e\n\u003ctd\u003eMcIntosh Solid Cinch™ binding posts for 2-, 4- and 8-ohm outputs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eMeter\u003c\/th\u003e\n\u003ctd\u003eDualView™ Power Output Meter\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eDimensions\u003c\/th\u003e\n\u003ctd\u003e17-17\/32 inches W x 13-3\/8 inches H x 29-17\/32 inches D\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd\u003e180 lbs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eShipping Weight\u003c\/th\u003e\n\u003ctd\u003e200 lbs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd\u003e3-year limited warranty\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003ch4\u003eIs the McIntosh MC901 sold as a pair?\u003c\/h4\u003e\n\u003cp\u003eNo. The MC901 is sold individually. One unit powers one loudspeaker, so two MC901 amplifiers are required for a stereo pair.\u003c\/p\u003e\n\u003ch4\u003eIs the MC901 a 900-watt amplifier?\u003c\/h4\u003e\n\u003cp\u003eNot in the conventional sense. It contains a 300-watt tube amplifier and a separate 600-watt solid state amplifier. The two outputs feed different sections of a bi-amp-capable loudspeaker and are not combined into one full-range output.\u003c\/p\u003e\n\u003ch4\u003eCan the MC901 be used with any speaker?\u003c\/h4\u003e\n\u003cp\u003eNo. The loudspeaker must provide separate, electrically isolated terminals for its low-frequency and mid\/high-frequency sections. Loudspeaker crossover requirements and the recommended crossover point should be confirmed before installation.\u003c\/p\u003e\n\u003ch4\u003eDoes the MC901 require an external crossover?\u003c\/h4\u003e\n\u003cp\u003eUsually not. The MC901 includes adjustable internal high-pass and low-pass filters. Direct inputs are available when an external crossover is preferred.\u003c\/p\u003e\n\u003ch4\u003eCan the tube and solid state sections be adjusted independently?\u003c\/h4\u003e\n\u003cp\u003eYes. Their relative levels can be adjusted from -6dB to +3dB, and the crossover filters can be configured for the connected loudspeaker.\u003c\/p\u003e\n\u003ch4\u003eWhat is the main difference between the MC901 and MC451?\u003c\/h4\u003e\n\u003cp\u003eThe MC901 provides twice the rated power of the MC451: 300 watts of tube power and 600 watts of solid state power versus 150 and 300 watts. It is also considerably larger and heavier.\u003c\/p\u003e\n\u003ch3\u003eAuthorized McIntosh Dealer Support\u003c\/h3\u003e\n\u003cp\u003eAudio Exchange is an authorized McIntosh dealer in Richmond, Virginia. Our team can help determine loudspeaker compatibility, plan crossover settings, confirm preamplifier connections and address the delivery, support and electrical requirements of an MC901 stereo system. Explore additional options in our \u003ca href=\"\/collections\/mcintosh-power-amplifiers\"\u003eMcIntosh Power Amplifiers collection\u003c\/a\u003e.\u003c\/p\u003e","brand":"McIntosh","offers":[{"title":"Default Title","offer_id":45731853402159,"sku":"MC901","price":22000.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0235\/1375\/9791\/files\/mcintosh-mc901-hybrid-dual-mono-amplifier-angle.jpg?v=1785682396","url":"https:\/\/audio-exchange.com\/products\/mcintosh-mc901-dual-mono-amplifier","provider":"Audio-Exchange","version":"1.0","type":"link"}