{"product_id":"fosi-audio-p4","title":"Fosi Audio P4","description":"\u003cp\u003eFosi Audio P4 is a compact solid-state stereo preamplifier that brings three RCA sources under one volume and tone-control stage.\u003c\/p\u003e\u003cp\u003eIts motorized analog volume control, remote operation, three-level gain, tone bypass and separate pre-out make it a practical partner for power amplifiers and powered subwoofers.\u003c\/p\u003e\u003ch2\u003eWhy it stands out\u003c\/h2\u003e\u003ch3\u003eThree-source analog hub\u003c\/h3\u003e\u003cp\u003eThree RCA inputs allow convenient switching among a DAC, streamer, CD player or other line-level source.\u003c\/p\u003e\u003ch3\u003eMotorized analog volume control\u003c\/h3\u003e\u003cp\u003eThe remote-driven analog potentiometer provides smooth level adjustment without replacing the analog signal path with digital volume control.\u003c\/p\u003e\u003ch3\u003eFlexible tone and gain adjustment\u003c\/h3\u003e\u003cp\u003eBass, treble, bypass and three gain levels help match different source levels and listening preferences.\u003c\/p\u003e\u003ch3\u003eLow-noise preamplifier performance\u003c\/h3\u003e\u003cp\u003eHigh SNR and low THD+N support clean system control in a compact all-metal chassis.\u003c\/p\u003e\u003ch2\u003eBest for\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eSystems with multiple line-level analog sources\u003c\/li\u003e\n\u003cli\u003ePower amplifiers needing source selection and remote volume\u003c\/li\u003e\n\u003cli\u003ePowered speaker systems\u003c\/li\u003e\n\u003cli\u003e2.1 systems using the volume-controlled pre-out\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eNot ideal for\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eDriving passive speakers directly\u003c\/li\u003e\n\u003cli\u003eTurntables without a built-in or external phono preamp\u003c\/li\u003e\n\u003cli\u003eUsers needing Bluetooth or digital audio inputs\u003c\/li\u003e\n\u003c\/ul\u003e\u003cdiv class=\"emiuzek-product-content-images\" style=\"width:100%;max-width:1100px;margin:8px auto 32px;\"\u003e\n\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0604\/7422\/8829\/files\/P4-006.webp?v=1764566905\" alt=\"Fosi Audio P4 stereo preamplifier low-noise audio performance\" loading=\"lazy\" style=\"display:block;width:100%;max-width:1100px;height:auto;margin:0 auto 24px;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0604\/7422\/8829\/files\/P4-002.webp?v=1764566905\" alt=\"Fosi Audio P4 three RCA inputs, RCA output and pre-out connections\" loading=\"lazy\" style=\"display:block;width:100%;max-width:1100px;height:auto;margin:0 auto 24px;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0604\/7422\/8829\/files\/P4-007.webp?v=1764566905\" alt=\"Fosi Audio P4 power amplifier, powered speaker and subwoofer setup scenarios\" loading=\"lazy\" style=\"display:block;width:100%;max-width:1100px;height:auto;margin:0 auto 24px;\"\u003e\n\u003c\/div\u003e\u003ch2\u003eEMiUZEK Buying Notes\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eP4 is a preamplifier and cannot directly power passive speakers.\u003c\/li\u003e\n\u003cli\u003eAll three inputs are line-level RCA; a standard turntable requires a phono preamp.\u003c\/li\u003e\n\u003cli\u003ePre-out is volume controlled and suitable for compatible powered subwoofers or powered speakers.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eFrequently asked questions\u003c\/h2\u003e\u003ch3\u003eCan P4 drive passive speakers?\u003c\/h3\u003e\u003cp\u003eNo. Connect its RCA output to a power amplifier that drives the passive speakers.\u003c\/p\u003e\u003ch3\u003eDoes P4 include Bluetooth?\u003c\/h3\u003e\u003cp\u003eNo. It is an analog RCA preamplifier.\u003c\/p\u003e\u003ch3\u003eCan I connect a turntable?\u003c\/h3\u003e\u003cp\u003eOnly if the turntable has a built-in phono stage or you use an external phono preamp.\u003c\/p\u003e\u003ch3\u003eWhat is pre-out for?\u003c\/h3\u003e\u003cp\u003eIt provides a volume-controlled line-level output for compatible powered speakers, a powered subwoofer or downstream equipment.\u003c\/p\u003e\u003ch3\u003eCan tone controls be bypassed?\u003c\/h3\u003e\u003cp\u003eYes. The bypass function provides a more direct signal path when tone adjustment is not needed.\u003c\/p\u003e\u003ch3\u003eWhat does the gain setting do?\u003c\/h3\u003e\u003cp\u003eThe three gain levels help match differing source output levels and system sensitivity.\u003c\/p\u003e\u003ch2\u003eHOW TO CONNECT\u003c\/h2\u003e\u003ch3\u003ePower amplifier system\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eSource:\u003c\/strong\u003e DAC, streamer, CD player or phono preamp\u003cbr\u003e\u003cstrong\u003eConnection:\u003c\/strong\u003e RCA input\u003cbr\u003e\u003cstrong\u003eOutput:\u003c\/strong\u003e RCA output\u003cbr\u003e\u003cstrong\u003eTarget:\u003c\/strong\u003e Power amplifier → passive speakers\u003cbr\u003e\u003cstrong\u003eNote:\u003c\/strong\u003e Select the source and use P4 for volume control.\u003c\/p\u003e\u003ch3\u003ePowered speaker system\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eSource:\u003c\/strong\u003e Up to three line-level sources\u003cbr\u003e\u003cstrong\u003eConnection:\u003c\/strong\u003e RCA input\u003cbr\u003e\u003cstrong\u003eOutput:\u003c\/strong\u003e Pre-out or RCA output\u003cbr\u003e\u003cstrong\u003eTarget:\u003c\/strong\u003e Powered speakers\u003cbr\u003e\u003cstrong\u003eNote:\u003c\/strong\u003e Begin with conservative volume settings on both devices.\u003c\/p\u003e\u003ch3\u003e2.1 system\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eSource:\u003c\/strong\u003e Line-level source\u003cbr\u003e\u003cstrong\u003eConnection:\u003c\/strong\u003e RCA input\u003cbr\u003e\u003cstrong\u003eOutput:\u003c\/strong\u003e RCA output + pre-out\u003cbr\u003e\u003cstrong\u003eTarget:\u003c\/strong\u003e Power amplifier and powered subwoofer\u003cbr\u003e\u003cstrong\u003eNote:\u003c\/strong\u003e Use pre-out for the powered subwoofer and confirm crossover settings.\u003c\/p\u003e\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\u003ch3\u003eAudio performance\u003c\/h3\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eFeature\u003c\/th\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eProduct type\u003c\/td\u003e\n\u003ctd\u003e2.0-channel solid-state preamplifier\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSNR\u003c\/td\u003e\n\u003ctd\u003e≥110dB\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDynamic range\u003c\/td\u003e\n\u003ctd\u003e≥110dB\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTHD+N\u003c\/td\u003e\n\u003ctd\u003e≤0.003%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCrosstalk\u003c\/td\u003e\n\u003ctd\u003e≥105dB\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNoise floor\u003c\/td\u003e\n\u003ctd\u003e≤9μV\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFrequency response\u003c\/td\u003e\n\u003ctd\u003e20Hz–20kHz (±0.1dB)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTone adjustment\u003c\/td\u003e\n\u003ctd\u003e±12dB\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch3\u003eConnectivity and power\u003c\/h3\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eFeature\u003c\/th\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eInputs\u003c\/td\u003e\n\u003ctd\u003eRCA × 3\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOutputs\u003c\/td\u003e\n\u003ctd\u003eRCA, pre-out\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGain adjustment\u003c\/td\u003e\n\u003ctd\u003e+3dB \/ +6dB \/ +9dB\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVolume control\u003c\/td\u003e\n\u003ctd\u003eMotorized analog potentiometer with remote\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower supply\u003c\/td\u003e\n\u003ctd\u003eDC 12V \/ 1.5A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch2\u003eRecommended System Setup\u003c\/h2\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eSetup\u003c\/th\u003e\n\u003cth\u003eConnection\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eStereo separates\u003c\/td\u003e\n\u003ctd\u003eSources → P4 → Power amplifier → Passive speakers\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePowered speakers\u003c\/td\u003e\n\u003ctd\u003eSources → P4 → Powered speakers\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2.1 separates\u003c\/td\u003e\n\u003ctd\u003eSources → P4 → Power amplifier + powered subwoofer\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch2\u003eAdditional Product Content\u003c\/h2\u003e\u003ch3\u003eFosi Audio product comparison\u003c\/h3\u003e\u003cp\u003eCompare the main Fosi Audio preamplifier choices by source support, outputs and the features that most affect system design.\u003c\/p\u003e\u003cdiv style=\"max-width:100%;overflow-x:auto;-webkit-overflow-scrolling:touch;\"\u003e\u003ctable style=\"min-width:760px;\"\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth style=\"min-width:150px;\"\u003eFeature\u003c\/th\u003e\n\u003cth style=\"min-width:190px;\"\u003eP4\u003c\/th\u003e\n\u003cth style=\"min-width:190px;\"\u003eP3\u003c\/th\u003e\n\u003cth style=\"min-width:190px;\"\u003eZP3\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eProduct position\u003c\/th\u003e\n\u003ctd\u003eCompact analog preamp\u003c\/td\u003e\n\u003ctd\u003eTube preamp + headphone amp\u003c\/td\u003e\n\u003ctd\u003eBalanced high-performance preamp\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eAnalog inputs\u003c\/th\u003e\n\u003ctd\u003eRCA × 3\u003c\/td\u003e\n\u003ctd\u003eRCA\u003c\/td\u003e\n\u003ctd\u003eRCA × 2, XLR\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWireless \/ digital inputs\u003c\/th\u003e\n\u003ctd\u003eNone\u003c\/td\u003e\n\u003ctd\u003eBluetooth 5.1\u003c\/td\u003e\n\u003ctd\u003eNone\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eMain outputs\u003c\/th\u003e\n\u003ctd\u003eRCA, pre-out\u003c\/td\u003e\n\u003ctd\u003eRCA, AUX\u003c\/td\u003e\n\u003ctd\u003eRCA, XLR, sub-out\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eHeadphone output\u003c\/th\u003e\n\u003ctd\u003eNo\u003c\/td\u003e\n\u003ctd\u003e3.5mm\u003c\/td\u003e\n\u003ctd\u003eNo\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eSpeaker amplification\u003c\/th\u003e\n\u003ctd\u003eNo\u003c\/td\u003e\n\u003ctd\u003eNo\u003c\/td\u003e\n\u003ctd\u003eNo\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eTube stage\u003c\/th\u003e\n\u003ctd\u003eNo\u003c\/td\u003e\n\u003ctd\u003eYes, replaceable 5654W\u003c\/td\u003e\n\u003ctd\u003eNo\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eTone controls\u003c\/th\u003e\n\u003ctd\u003eBass and treble with bypass\u003c\/td\u003e\n\u003ctd\u003eBass and treble\u003c\/td\u003e\n\u003ctd\u003eBass and treble\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eRemote control\u003c\/th\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003ctd\u003eNo\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eTHD+N\u003c\/th\u003e\n\u003ctd\u003e≤0.003%\u003c\/td\u003e\n\u003ctd\u003e≤0.02%\u003c\/td\u003e\n\u003ctd\u003e≤0.0007%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eSNR\u003c\/th\u003e\n\u003ctd\u003e≥110dB\u003c\/td\u003e\n\u003ctd\u003e≥103dB\u003c\/td\u003e\n\u003ctd\u003e≥115dB\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eBest use\u003c\/th\u003e\n\u003ctd\u003eThree analog sources and powered sub expansion\u003c\/td\u003e\n\u003ctd\u003eBluetooth tube preamp and headphones\u003c\/td\u003e\n\u003ctd\u003eBalanced stereo system integration\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e","brand":"Fosi Audio","offers":[{"title":"Black \/ US","offer_id":43853159497821,"sku":"Fosi-Audio-P4-Black-US","price":606.0,"currency_code":"BRL","in_stock":true},{"title":"Black \/ EU","offer_id":43853159530589,"sku":"Fosi-Audio-P4-Black-EU","price":606.0,"currency_code":"BRL","in_stock":true},{"title":"Black \/ UK","offer_id":43853159563357,"sku":"Fosi-Audio-P4-Black-UK","price":606.0,"currency_code":"BRL","in_stock":true},{"title":"Black \/ AU","offer_id":43853159596125,"sku":"Fosi-Audio-P4-Black-AU","price":606.0,"currency_code":"BRL","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0604\/7422\/8829\/files\/Fosi_Audio_P4_a3a48823-1baa-40ec-a11d-cd40802f54e5.webp?v=1785379555","url":"https:\/\/emiuzek.com\/pt-br\/products\/fosi-audio-p4","provider":"EMiUZEK","version":"1.0","type":"link"}