{"product_id":"warm-audio-wa-mpx-b1","title":"Warm Audio WA-MPX Single-Channel Tube Microphone Preamplifier (Warehouse Deal, Demo, minor marks)","description":"\u003cp\u003eThe Warm Audio WA-MPX is a single-channel tube microphone preamplifier that reproduces the AMPEX 351-style preamp, the tape-era tube preamp behind countless classic recordings from Elvis Presley to Nirvana. With three vacuum tubes, custom CineMag USA transformers, and up to 90 dB of gain through a 300V circuit, the WA-MPX delivers everything from pristine clean headroom to harmonically rich tube saturation with selectable tape emulation.\u003c\/p\u003e\n\u003ch3\u003eTube Circuit and Gain Structure\u003c\/h3\u003e\n\u003cp\u003eThe WA-MPX runs two 12AX7 tubes and one 12AU7 through a hand-wired 300V signal path. In normal operation, the first 12AX7 provides 70 dB of clean tube gain. Engaging the High Gain switch brings the second triode into the circuit, boosting available gain to 90 dB for low-output passive ribbon and dynamic microphones. The Tone switch toggles the CineMag input transformer impedance between 600 and 150 Ohms, altering the frequency response and harmonic interaction between the microphone and preamp.\u003c\/p\u003e\n\n\u003ch3\u003eTape Saturation and Filters\u003c\/h3\u003e\n\u003cp\u003eThe Tape Saturation switch engages a discrete analog circuit that adds harmonic distortion, gentle compression, and non-linear frequency response to emulate the sound of analog tape machines running at 15 IPS. An 80 Hz high-pass filter removes low-end rumble before the gain stage, and a 2 kHz low-pass filter rolls off upper-mids and highs for a focused, lo-fi character when creative tone shaping is the goal.\u003c\/p\u003e\n\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eType:\u003c\/strong\u003e Single-channel tube mic\/line\/instrument preamplifier\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTopology:\u003c\/strong\u003e AMPEX 351-style, fully discrete, hand-wired\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTubes:\u003c\/strong\u003e 2x 12AX7, 1x 12AU7\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTransformers:\u003c\/strong\u003e CineMag USA (custom large-core, input and output)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGain:\u003c\/strong\u003e 90 dB (with High Gain engaged)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCircuit voltage:\u003c\/strong\u003e 300V\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFilters:\u003c\/strong\u003e 80 Hz high-pass, 2 kHz low-pass\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTape saturation:\u003c\/strong\u003e Selectable, emulates 15 IPS reel-to-reel\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eControls:\u003c\/strong\u003e Input gain, output level, input select, 48V, polarity, tone, high gain, HPF, LPF, tape saturation\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInputs:\u003c\/strong\u003e XLR mic, TRS line, TS instrument\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOutputs:\u003c\/strong\u003e XLR, TRS\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMetering:\u003c\/strong\u003e VU meter\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePower:\u003c\/strong\u003e 115\/230V, IEC\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRack size:\u003c\/strong\u003e 2U, 19\"\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDimensions:\u003c\/strong\u003e 483 x 89 x 222 mm (19 x 3.5 x 8.7\")\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eIn the Box\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eWarm Audio WA-MPX\u003c\/li\u003e\n\u003cli\u003eIEC power cable\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Warm Audio","offers":[{"title":"Default Title","offer_id":50525586489593,"sku":"WA-MPX-b1","price":1186.55,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0746\/5766\/1177\/files\/WA-MPX_cb88a365-1499-4b1c-b6b5-68d76c6806c7.jpg?v=1765322145","url":"https:\/\/blackoutaudio.com\/products\/warm-audio-wa-mpx-b1","provider":"Blackout Audio","version":"1.0","type":"link"}