{"product_id":"heritage-audio-6673-80-series-microphone-preamp-eq-module","title":"Heritage Audio 6673 80 Series Microphone Preamp and EQ Module","description":"\u003cp\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003ch2\u003e\u003cbr\u003e\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;\"\u003eHeritage Audio 6673 Preamp EQ Module Overview\u003c\/h2\u003e\n\u003ciframe src=\"https:\/\/www.youtube.com\/embed\/et3BEkLrt4s?si=wbE0-_zrgPHVbdSO\" style=\"width: 100%; max-width: 800px; height: 450px; display: block; margin: 0 auto; border-radius: 8px;\"\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 src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0646\/4031\/9643\/files\/Heritage_Audio_6673_Microphone_Preamplifier_Module_front_on_view.png?v=1771551468\" alt=\"Heritage Audio 6673 80 series microphone preamp four-band EQ module\"\u003e\u003c\/div\u003e\n\u003cdiv class=\"par-text\"\u003e\n\u003ch2\u003e1073 Preamp + 1066 Constant-Q Mid = Four-Band EQ Monster\u003c\/h2\u003e\n\u003cp\u003eThe 6673 solves a 50-year-old problem: choosing between the 1073's punchy three-band EQ and the 1066's sweet constant-Q midband. Heritage Audio put both in one module. You get the 1073's full three-band circuit plus the 1066's inductor-based constant-Q mid EQ — four bands total. The 1073 mid section was expanded with three additional frequencies (240, 360, 530 Hz) for better low-mid control. High shelf now switches between 10, 12, or 16 kHz instead of being fixed at 12 kHz.\u003c\/p\u003e\n\u003cp\u003eSame Class A 73-style preamp as the 8173: 80 dB gain in 5 dB steps, HI\/LO impedance switch (1,200 Ω \/ 300 Ω minimum), Carnhill transformers, 2N3055-driven output stage. Noise below -100 dBu, THD under 0.025% at 1 kHz. Handwired in Spain on five plug-in PCB cards using 1970s soldering techniques.\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 src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0646\/4031\/9643\/files\/Heritage_Audio_6673_Microphone_Preamplifier_Module_right_scaled_view.png?v=1771551468\" alt=\"Heritage Audio 6673 four band EQ 1073 1066 inductor constant Q\"\u003e\u003c\/div\u003e\n\u003cdiv class=\"par-text\"\u003e\n\u003ch2\u003eFour Inductor-Based EQ Bands Cover 35 Hz to 16 kHz\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eHigh shelf (Baxandall):\u003c\/strong\u003e ±16 dB at 10, 12, or 16 kHz\u003cbr\u003e\u003cstrong\u003eLow shelf (Baxandall):\u003c\/strong\u003e ±16 dB at 35, 60, 110, or 220 Hz\u003cbr\u003e\u003cstrong\u003e1073 mid (fixed Q, dual inductor):\u003c\/strong\u003e ±18 dB at 240, 360, 530, 700, 1100, 1600, 3200, 4800, 7200, 10000 Hz\u003cbr\u003e\u003cstrong\u003e1066 mid (constant Q, inductor):\u003c\/strong\u003e ±18 dB at 700, 1200, 2400, 3600, 7000 Hz\u003cbr\u003e\u003cstrong\u003eHigh-pass filter:\u003c\/strong\u003e 18 dB\/octave at 50, 80, or 300 Hz\u003c\/p\u003e\n\u003cp\u003eBoth mid bands can be used simultaneously — boost at 700 Hz with the 1066 circuit for thick guitars, then cut at 360 Hz with the 1073 band to clear mud. The constant-Q 1066 circuit maintains consistent bandwidth regardless of boost\/cut amount, unlike the 1073's fixed-Q design.\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 src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0646\/4031\/9643\/files\/Heritage_Audio_6673_Microphone_Preamplifier_Module_right_opened_view.png?v=1771551468\" alt=\"Heritage Audio 6673 Class A ribbon mic 80dB gain impedance\"\u003e\u003c\/div\u003e\n\u003cdiv class=\"par-text\"\u003e\n\u003ch2\u003e80 Series Compatible, Frame 8, or Rack 2 Ready\u003c\/h2\u003e\n\u003cp\u003eFits vintage 80 Series consoles, Heritage Audio Frame 8, and Rack 2 enclosures. 10 dB Class A line amplifier with 10 kΩ bridging input impedance. Output impedance below 75 Ω transformer-balanced and floating, drives 600 Ω loads. Maximum output greater than +26 dBu into 600 Ω and greater than +32 dBu into 10 kΩ. Frequency response 20 Hz (+0.3 dB) to 20 kHz (-0.2 dB).\u003c\/p\u003e\n\u003cp\u003ePower consumption under 110 mA at 24V DC (supplied by chassis). As an authorized dealer, Pro Audio Reserve ensures you receive a genuine Heritage Audio product backed by full manufacturer warranty and long-term support.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003ch3\u003eHighlights\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e1073 Class A preamp + 1066 constant-Q mid EQ + expanded 1073 mid = 4-band module\u003c\/li\u003e\n\u003cli\u003e80 dB Class A mic preamp (5 dB steps), 10 dB Class A line amp\u003c\/li\u003e\n\u003cli\u003eHI\/LO mic impedance: 1,200 Ω \/ 300 Ω minimum (ribbon compatible)\u003c\/li\u003e\n\u003cli\u003eCarnhill input\/output transformers, 2N3055 output stage\u003c\/li\u003e\n\u003cli\u003eHigh shelf (Baxandall): ±16 dB at 10, 12, 16 kHz\u003c\/li\u003e\n\u003cli\u003eLow shelf (Baxandall): ±16 dB at 35, 60, 110, 220 Hz\u003c\/li\u003e\n\u003cli\u003e1073 mid (dual inductor, fixed Q): ±18 dB at 10 frequencies (240–10k Hz)\u003c\/li\u003e\n\u003cli\u003e1066 mid (inductor, constant Q): ±18 dB at 700, 1200, 2400, 3600, 7000 Hz\u003c\/li\u003e\n\u003cli\u003e18 dB\/oct high-pass: 50, 80, 300 Hz (inductor)\u003c\/li\u003e\n\u003cli\u003eMax output: \u0026gt;+26 dBu (600 Ω), \u0026gt;+32 dBu (10 kΩ)\u003c\/li\u003e\n\u003cli\u003eNoise: \u0026lt;-100 dBu | THD: \u0026lt;0.025% (1 kHz), \u0026lt;0.05% (100 Hz)\u003c\/li\u003e\n\u003cli\u003eFrequency response: 20 Hz (+0.3 dB) to 20 kHz (-0.2 dB)\u003c\/li\u003e\n\u003cli\u003eHandwired in Spain on five PCB cards\u003c\/li\u003e\n\u003cli\u003eCompatible: 80 Series consoles, Frame 8, Rack 2\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eHeritage Audio 6673 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\u003eFormat\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e80 Series module (1073-sized)\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\u003eCompatible Chassis\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eVintage 80 Series consoles, Heritage Audio Frame 8, Heritage Audio Rack 2\u003c\/td\u003e\n\u003c\/tr\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;\"\u003eClass A, solid state (73-style)\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\u003eMaximum Mic Preamp Gain\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eSlightly greater than 80 dB (in 5 dB steps)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003eMic Input Impedance\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eHI: 1,200 Ω minimum | LO: 300 Ω minimum (transformer balanced and floating)\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\u003eLine Input Impedance\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e10 kΩ bridging (transformer balanced and floating)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003eLine Amplifier\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e10 dB Class A, 2N3055-driven high headroom output stage\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\u003eOutput Impedance\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eLess than 75 Ω (transformer balanced and floating)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003eMaximum Output\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u0026gt;+26 dBu into 600 Ω | \u0026gt;+32 dBu into 10 kΩ\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 (+0.3 dB) to 20 kHz (-0.2 dB)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003eNoise\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eLess than -100 dBu\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\u003eTHD\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eLess than 0.025% at 1 kHz | Less than 0.05% at 100 Hz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003eHigh Frequency EQ\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e±16 dB shelving at 10, 12, or 16 kHz (Baxandall)\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\u003eLow Frequency EQ\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e±16 dB shelving at 35, 60, 110, or 220 Hz (Baxandall)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003e1073 Mid EQ\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e±18 dB peaking (fixed Q, dual inductor) at 240, 360, 530, 700, 1100, 1600, 3200, 4800, 7200, 10000 Hz\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\u003e1066 Mid EQ\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e±18 dB peaking (constant Q, inductor) at 700, 1200, 2400, 3600, 7000 Hz\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;\"\u003e18 dB\/octave at 50, 80, or 300 Hz (inductor based)\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 supplied by chassis\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003ePower Consumption\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eLess than 110 mA @ 24V DC\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;\"\u003eFive plug-in PCB cards, fully handwired, Carnhill transformers\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003eManufactured\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eSpain\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;\"\u003eHeritage Audio 6673 80 Series Microphone Preamp and EQ Module\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #fafafa;\"\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":"Heritage Audio","offers":[{"title":"Default Title","offer_id":48024187306139,"sku":null,"price":2999.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0646\/4031\/9643\/files\/Heritage_Audio_6673_Microphone_Preamplifier_Module_right_scaled_view.png?v=1771551468","url":"https:\/\/proaudioreserve.com\/products\/heritage-audio-6673-80-series-microphone-preamp-eq-module","provider":"Pro Audio Reserve","version":"1.0","type":"link"}