{"product_id":"useful-arts-sfp-30-tube-microphone-preamp","title":"Useful Arts SFP-30 Single Channel Tube Microphone Preamp","description":"\u003ch2 style=\"text-align: center;\"\u003eUseful Arts SFP-30 Single Channel Tube Microphone Preamp\u003c\/h2\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003c!-- Section 1 --\u003e\n\u003cdiv class=\"par-section\"\u003e\n\u003cdiv class=\"par-image\"\u003e\u003cimg alt=\"Useful Arts SFP-30 single channel tube microphone preamp\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0646\/4031\/9643\/files\/USEFUL_ARTS_SPF-30_FRONT.png?v=1770160983\"\u003e\u003c\/div\u003e\n\u003cdiv class=\"par-text\"\u003e\n\u003ch2\u003eArtfully Curated Tubes for Forward, Punchy Sound\u003c\/h2\u003e\n\u003cp\u003eUseful Arts designed the SFP-30 to be clear, present, and edgy rather than dark and creamy, specifically targeting vocals that sound forward and intimate. The carefully curated tube selection employs an EF-806 pentode for the input stage, adding third-order harmonics that contribute to clarity and bite. Two high-current ECC82 triodes handle the final gain stages, producing second-order harmonic content that adds richness and thickness without sounding dark.\u003c\/p\u003e\n\u003cp\u003eYou won't find the pedestrian 12AX7 anywhere in the SFP-30's signal path. Instead, Useful Arts selected tubes specifically for what they do best — bringing out harmonics that increase clarity and euphonics. Each gain stage is single-ended Class A, ensuring the purest possible signal path with minimal distortion artifacts when running clean.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c!-- Section 2 --\u003e\n\u003cdiv class=\"par-section reverse\"\u003e\n\u003cdiv class=\"par-image\"\u003e\u003cimg alt=\"Useful Arts SFP-30 Color control knob harmonic distortion\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0646\/4031\/9643\/files\/USEFUL_ARTS_SPF-30_FRONT.png?v=1770160983\"\u003e\u003c\/div\u003e\n\u003cdiv class=\"par-text\"\u003e\n\u003ch2\u003eVariable Color Control: From Polite to Aggressive\u003c\/h2\u003e\n\u003cp\u003eUnlike preamps designed to maintain a fixed distortion-to-gain ratio, the SFP-30's Color knob puts artistic choice directly in your hands. At a setting of zero, the preamp sounds squeaky clean and polite. Fully engaged, it adds around 10 dB of gain and increases distortion artifacts nearly tenfold, delivering a full, aggressive sound that sits boldly in a mix and commands attention.\u003c\/p\u003e\n\u003cp\u003eThis incredibly broad creative range allows the SFP-30 to serve up very different sounds for different sources, tracks, and musical genres. The harmonic distortion has a psychoacoustic spectral effect that humans perceive similarly to equalization, but instead of filtering existing frequencies, the tube preamp is actually adding harmonic content that isn't in the original signal — and Useful Arts has made that distortion sound absolutely amazing.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c!-- Section 3 --\u003e\n\u003cdiv class=\"par-section\"\u003e\n\u003cdiv class=\"par-image\"\u003e\u003cimg alt=\"Useful Arts SFP-30 Audio Magnetics transformers CineMag\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0646\/4031\/9643\/files\/USEFUL_ARTS_SPF-30_FRONT.png?v=1770160983\"\u003e\u003c\/div\u003e\n\u003cdiv class=\"par-text\"\u003e\n\u003ch2\u003ePremium Transformers and Maximum Headroom\u003c\/h2\u003e\n\u003cp\u003eThe SFP-30 features Audio Magnetics input and output transformers custom-wound by CineMag, including a plate inductor and an output transformer with 50% nickel core. This transformer design contributes to the preamp's flat frequency response of 20 Hz to 30 kHz (±2 dB) while maintaining the musical character Useful Arts is known for.\u003c\/p\u003e\n\u003cp\u003eCombined with the high-voltage power supply delivering over 270 volts, the SFP-30 offers massive headroom with over 60 dB of usable gain. Input and output levels of the triode stages are separately controllable via detented attenuators, and combined with the Color knob, this gives you precise control over both gain structure and tonal character.\u003c\/p\u003e\n\u003ch3\u003eHighlights\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eSingle-channel Class A tube preamp with identical circuitry to the SFP-60\u003c\/li\u003e\n\u003cli\u003eEF-806 pentode input stage and dual ECC82 triode gain stages\u003c\/li\u003e\n\u003cli\u003eVariable Color control for adjustable harmonic distortion (clean to aggressive)\u003c\/li\u003e\n\u003cli\u003eAudio Magnetics transformers custom-wound by CineMag with 50% nickel core output\u003c\/li\u003e\n\u003cli\u003eOver 60 dB of usable gain with maximum headroom\u003c\/li\u003e\n\u003cli\u003eHigh-voltage soft-start power supply delivering over 270 volts\u003c\/li\u003e\n\u003cli\u003eSealed gold-plated relays for all switching functions\u003c\/li\u003e\n\u003cli\u003eFront-panel instrument input and rear-panel XLR mic input\u003c\/li\u003e\n\u003cli\u003eSwitchable phantom power, pad, phase reverse, and highpass filter\u003c\/li\u003e\n\u003cli\u003eCompact tabletop design with aircraft-grade aluminum faceplate\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eUseful Arts SFP-30 Specifications\u003c\/h3\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse; border: 1px solid #ccc;\"\u003e\n\u003cthead\u003e\n\u003ctr style=\"background-color: #f2f2f2;\"\u003e\n\u003cth style=\"text-align: left; padding: 10px; border: 1px solid #ccc; width: 35%;\"\u003eSpecification\u003c\/th\u003e\n\u003cth style=\"text-align: left; padding: 10px; border: 1px solid #ccc;\"\u003eDetails\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003ePreamp Type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eAll-tube, single-ended Class A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #fafafa;\"\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003eNumber of Channels\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003eTubes\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e1 x JJ EF-806 pentode, 2 x JJ ECC82 triodes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #fafafa;\"\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003eFrequency Response\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e20 Hz – 30 kHz, ±2 dB\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003eUsable Gain\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eOver 60 dB (including Color knob engagement)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #fafafa;\"\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003eTransformers\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eAudio Magnetics input\/output, custom-wound by CineMag; 50% nickel core output transformer\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003ePower Supply\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eSeparate regulated DC supplies for filaments, phantom, and high voltage (270V+)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #fafafa;\"\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003ePhantom Power\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e+48V switchable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003eInput Pad\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e-22 dB switchable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #fafafa;\"\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003eHighpass Filter\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eSwitchable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003ePhase Reverse\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eSwitchable polarity reverse\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #fafafa;\"\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003eAnalog Inputs\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e1 x rear-panel XLR (mic), 1 x front-panel 1\/4\" (instrument)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003eAnalog Outputs\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e1 x XLR (transformer-balanced line output)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #fafafa;\"\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003eMetering\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eVU meter (op-amp buffered)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003ePower Source\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eStandard IEC AC cable (115\/230V selectable)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #fafafa;\"\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003eDimensions (H x W x D)\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e4.5\" x 9\" x 10\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003eWeight\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e8 lbs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #fafafa;\"\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003eConstruction\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e0.190\" aircraft-grade aluminum faceplate, fully modular design, gold-plated connectors\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eWhat's in the Box\u003c\/h3\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse; border: 1px solid #ccc;\"\u003e\n\u003cthead\u003e\n\u003ctr style=\"background-color: #f2f2f2;\"\u003e\n\u003cth style=\"text-align: left; padding: 10px; border: 1px solid #ccc;\"\u003eIncluded Items\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eUseful Arts SFP-30 Tube Microphone Preamp\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #fafafa;\"\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003ePower Cable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eUser Documentation\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Useful Arts","offers":[{"title":"Default Title","offer_id":47944209072283,"sku":"SFP-30","price":1299.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0646\/4031\/9643\/files\/USEFUL_ARTS_SPF-30_FRONT.png?v=1770160983","url":"https:\/\/proaudioreserve.com\/products\/useful-arts-sfp-30-tube-microphone-preamp","provider":"Pro Audio Reserve","version":"1.0","type":"link"}