{"title":"Shop Useful Arts","description":"\u003cp\u003eAt Pro Audio Reserve, we're proud to offer Useful Arts' exceptional line of hand-crafted signal processors. This boutique manufacturer draws inspiration from the golden era of recording, when custom tube preamps were built to capture the unique character of each performance. Rather than focusing solely on technical specifications, Useful Arts designs their gear to preserve dynamics and enhance the natural tonal richness of your recordings. Each piece is meticulously hand-built to deliver the kind of vibrant, musical sound that sits beautifully in a mix without requiring endless processing. Experience the difference that thoughtful, artisan-level engineering brings to your studio chain.\u003c\/p\u003e","products":[{"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"},{"product_id":"useful-arts-sfp-60-dual-tube-microphone-preamp","title":"Useful Arts SFP-60 Dual Channel Tube Microphone Preamp","description":"\u003ch2 style=\"text-align: center;\"\u003eUseful Arts SFP-60 Dual Channel Tube Microphone Preamp\u003c\/h2\u003e\n\u003c!-- Video Section with Keyword Title --\u003e\n\u003cdiv style=\"margin: 20px auto 10px auto; text-align: center; max-width: 800px;\"\u003e\n\u003ch2 style=\"font-size: 20px; margin-bottom: 12px;\"\u003eUseful Arts SFP-60 Tube Preamp Demo\u003c\/h2\u003e\n\u003ciframe style=\"width: 100%; max-width: 800px; height: 450px; display: block; margin: 0 auto; border-radius: 8px;\" src=\"https:\/\/www.youtube.com\/embed\/lgjeA7T1fsA?si=UKSnZhX7Mgcbo2wz\"\u003e\n  \u003c\/iframe\u003e\n\u003c\/div\u003e\n\u003c!-- Section 1 --\u003e\n\u003cdiv class=\"par-section\"\u003e\n\u003cdiv class=\"par-image\"\u003e\u003cimg alt=\"Useful Arts SFP-60 dual channel tube microphone preamp\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0646\/4031\/9643\/files\/Useful_arts_sfp_top_view.png?v=1770159636\"\u003e\u003c\/div\u003e\n\u003cdiv class=\"par-text\"\u003e\n\u003ch2\u003eClear, Present, and Forward Vocal Character\u003c\/h2\u003e\n\u003cp\u003eThe sound of the Useful Arts SFP-60 is more clear, present, and edgy than dark and creamy, specifically designed to make vocals sound forward and intimate. This is accomplished by using tubes for what they are best at — accentuating harmonics that make sound more clear and pleasing to the ear in the real world.\u003c\/p\u003e\n\u003cp\u003eEach channel features an EF-806 pentode input tube that adds third-order harmonic content contributing to the clarity and bite associated with great early radio recordings. The final two gain stages use high-current ECC82 triodes that contribute second-order harmonic components, adding richness and thickness to the sound without sounding dark. The pedestrian 12AX7 — wonderful in guitar amps but common in mass-market tube preamps — is nowhere to be found in the SFP-60.\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-60 Color control variable harmonic distortion\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0646\/4031\/9643\/files\/Useful_arts_sfp_60_front_view.png?v=1770159635\"\u003e\u003c\/div\u003e\n\u003cdiv class=\"par-text\"\u003e\n\u003ch2\u003eVariable Color Control for Artistic Distortion\u003c\/h2\u003e\n\u003cp\u003eUnlike most preamps designed to maintain a predetermined ratio of distortion to gain, the SFP-60 puts the artistic choice of distortion directly in your hands. At a Color setting of zero, the preamp is very clean and sounds polite. At a setting of ten, it adds about 10 dB of gain and increases distortion artifacts by nearly ten times, resulting in an aggressive, full sound that stands out in a mix and grabs the listener's attention.\u003c\/p\u003e\n\u003cp\u003eThe character of harmonic distortion in the SFP-60 has a spectral effect that feels EQ-related but is completely different from equalization. While EQ filters give you more or less of what you put in (along with undesirable phase shifts), the preamp is actually adding signal that isn't present in the original — and every audio device ever made introduces distortion, so Useful Arts made it a good thing.\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-60 transformer balanced inputs outputs\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0646\/4031\/9643\/files\/USEFUL_ARTS_SPF-30_REAR_1.png?v=1770161444\"\u003e\u003c\/div\u003e\n\u003cdiv class=\"par-text\"\u003e\n\u003ch2\u003eOver 60dB of Usable Gain With Maximum Headroom\u003c\/h2\u003e\n\u003cp\u003eThe input and output levels of the triode stages in the SFP-60 are separately controllable by detented attenuators, and combined with the Color control, the SFP-60 provides just over 60 dB of usable gain. The high-voltage soft-start power supply delivers over 270 volts of clean, regulated power to ensure maximum headroom and the lowest noise floor possible.\u003c\/p\u003e\n\u003cp\u003eFrequency response is flat within 2 dB from 20 Hz to 20 kHz. Each channel features transformer-balanced inputs and outputs using gold-plated XLR connectors, along with an op-amp buffered VU meter that ensures the signal is not loaded by the metering circuit. The audio power supply features a toroidal dual-primary transformer and linear regulation for lowest noise.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003ch3\u003eHighlights\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eTwo-channel Class A tube preamp with single-ended design\u003c\/li\u003e\n\u003cli\u003eEF-806 pentode input stages and dual ECC82 triode gain stages per channel\u003c\/li\u003e\n\u003cli\u003eVariable Color control for adjustable harmonic distortion (polite to aggressive)\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\u003eTransformer-balanced inputs and outputs with gold-plated XLR connectors\u003c\/li\u003e\n\u003cli\u003eSealed gold-plated relays for all switching functions (no signal passes through switches)\u003c\/li\u003e\n\u003cli\u003eDual front-panel instrument inputs and rear-panel XLR mic inputs\u003c\/li\u003e\n\u003cli\u003eSwitchable phantom power, pad, phase reverse, and high-pass filter per channel\u003c\/li\u003e\n\u003cli\u003eVU meters per channel (op-amp buffered)\u003c\/li\u003e\n\u003cli\u003eAircraft-grade aluminum faceplate with laser-engraved markings\u003c\/li\u003e\n\u003cli\u003e2U rackmount design\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eUseful Arts SFP-60 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;\"\u003e2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003eTubes (Per Channel)\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e1 x JJ EF-806 pentode, 1 x JJ ECC82 triode\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 – 20 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\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+); toroidal dual-primary transformer with linear regulation\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\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 per channel\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\u003eInput Pad\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e-22 dB switchable per channel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003eHigh-Pass Filter\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eSwitchable per channel\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\u003ePhase Reverse\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eSwitchable polarity reverse per channel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003eColor Control\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eVariable harmonic distortion per channel (0-10)\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;\"\u003e2 x rear-panel XLR (mic), 2 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;\"\u003e2 x XLR (transformer-balanced line outputs)\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;\"\u003eDual VU meters (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\u003eRack Spaces\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e2U\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\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 (dark green anodized), fully modular design, gold-plated connectors, laser-engraved markings\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-60 Dual Channel 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","brand":"Useful Arts","offers":[{"title":"Default Title","offer_id":47944209957019,"sku":"SFP-60","price":2999.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0646\/4031\/9643\/files\/Useful_arts_sfp_60_front_view.png?v=1770159635"},{"product_id":"useful-arts-swarm-4-channel-microphone-preamp","title":"Useful Arts Swarm 4-Channel Solid State Microphone Preamp","description":"\u003c!-- Video Section with Keyword Title --\u003e\n\u003cdiv style=\"margin: 20px auto 10px auto; text-align: center; max-width: 800px;\"\u003e\n\u003ch2 style=\"font-size: 20px; margin-bottom: 12px;\"\u003eUseful Arts Swarm 4-Channel Preamp Overview\u003c\/h2\u003e\n\u003ciframe style=\"width: 100%; max-width: 800px; height: 450px; display: block; margin: 0 auto; border-radius: 8px;\" src=\"https:\/\/www.youtube.com\/embed\/rJQcq__k3uM?si=IpLwRHFqtrftxYti\"\u003e\n  \u003c\/iframe\u003e\n\u003c\/div\u003e\n\u003c!-- Section 1 --\u003e\n\u003cdiv class=\"par-section\"\u003e\n\u003cdiv class=\"par-image\"\u003e\u003cimg alt=\"Useful Arts Swarm 4-channel solid state microphone preamp\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0646\/4031\/9643\/files\/usefularts_swarm_angle2-scaled.png?v=1770161746\"\u003e\u003c\/div\u003e\n\u003cdiv class=\"par-text\"\u003e\n\u003ch2\u003eDiscrete Gain Cells and Custom CineMag Transformers\u003c\/h2\u003e\n\u003cp\u003eThe Useful Arts Swarm features discrete transistor gain cell topology on all four channels, delivering sound quality that rivals solid-state preamps costing well over $1000. Each channel is equipped with a custom CineMag input transformer and transformer-coupled output, ensuring the same huge, dimensional sound that made the Hornet preamp a studio favorite.\u003c\/p\u003e\n\u003cp\u003eUnlike the generic preamps found in most audio interfaces, the Swarm has a distinct sonic personality. The discrete transistor design and high-quality transformers on both input and output work together to create a rich, powerful signal path that sits naturally in a mix without requiring extensive processing downstream.\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 Swarm Color control variable saturation\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0646\/4031\/9643\/files\/usefularts_swarm_front-scaled.png?v=1770161741\"\u003e\u003c\/div\u003e\n\u003cdiv class=\"par-text\"\u003e\n\u003ch2\u003eExclusive Color Control for Enhanced Character\u003c\/h2\u003e\n\u003cp\u003eThe Swarm's Color control puts creative tone shaping at your fingertips on each of the four channels. This exclusive Useful Arts feature enhances and thickens the personality of your microphone or instrument without the need for compression or EQ, adding harmonic richness that helps sources punch through a mix naturally.\u003c\/p\u003e\n\u003cp\u003eCombined with the discrete gain cell topology and transformers, the Color control allows you to dial in everything from clean and transparent to bold and aggressive, giving each channel its own character while maintaining the cohesive sound quality the Swarm is known for. This level of tonal flexibility makes the Swarm ideal for capturing diverse sources in a single session.\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 Swarm JFET DI inputs four channels\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0646\/4031\/9643\/files\/usefularts_swarm_angle2-scaled.png?v=1770161746\"\u003e\u003c\/div\u003e\n\u003cdiv class=\"par-text\"\u003e\n\u003ch2\u003eJFET Direct Inputs on Every Channel\u003c\/h2\u003e\n\u003cp\u003eEach of the four channels on the Swarm includes a high-quality JFET direct input, making it easy to track bass, guitar, keyboards, and other instruments alongside microphone sources. The JFET design provides high input impedance and exceptional clarity, preserving the natural tone of your instruments while benefiting from the Swarm's transformers and Color control.\u003c\/p\u003e\n\u003cp\u003eThis flexibility makes the Swarm perfect for handling entire sessions — track a drum kit with overheads and spot mics, add a DI'd bass, and capture keyboards or guitar all through a single, cohesive front end. The ability to switch between mic and DI inputs on each channel means you can quickly adapt to different tracking scenarios without repatching.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003ch3\u003eHighlights\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eFour independent mic\/DI channels in a 1U rackmount design\u003c\/li\u003e\n\u003cli\u003eDiscrete transistor gain cell topology on all channels\u003c\/li\u003e\n\u003cli\u003eCustom CineMag input transformers and transformer-coupled outputs\u003c\/li\u003e\n\u003cli\u003eExclusive Color control per channel for variable harmonic enhancement\u003c\/li\u003e\n\u003cli\u003eHigh-quality JFET direct inputs on every channel\u003c\/li\u003e\n\u003cli\u003eSwitchable phantom power per channel\u003c\/li\u003e\n\u003cli\u003e22 dB pad per channel for high-output sources\u003c\/li\u003e\n\u003cli\u003ePhase reverse control per channel\u003c\/li\u003e\n\u003cli\u003eHigh-pass filter per channel\u003c\/li\u003e\n\u003cli\u003eHand-built in the USA\u003c\/li\u003e\n\u003cli\u003eAffordable alternative to high-end solid-state preamps\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eUseful Arts Swarm 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;\"\u003eSolid-state, discrete transistor gain cells\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;\"\u003e4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003eInput Transformers\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eCustom CineMag transformers per channel\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\u003eOutputs\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eTransformer-coupled per channel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003eDirect Inputs\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eJFET DI per channel\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 per channel\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 per channel\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\u003eHigh-Pass Filter\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eSwitchable per channel\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 per channel\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\u003eColor Control\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eVariable harmonic enhancement per channel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003eRack Spaces\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e1U\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;\"\u003eHand-built in the USA\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 Swarm 4-Channel 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","brand":"Useful Arts","offers":[{"title":"Default Title","offer_id":47944210284699,"sku":"SWARM","price":1799.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0646\/4031\/9643\/files\/usefularts_swarm_front-scaled.png?v=1770161741"}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0646\/4031\/9643\/collections\/Useful-Arts-Logo-slogan-black.png?v=1770218990","url":"https:\/\/proaudioreserve.com\/collections\/shop-useful-arts.oembed","provider":"Pro Audio Reserve","version":"1.0","type":"link"}