{"product_id":"heritage-audio-grandchild-670-vari-mu-tube-compressor-500-series","title":"Heritage Audio Grandchild 670 Vari-Mu Stereo Tube Compressor 500 Series","description":"\u003c!-- Video Section --\u003e\n\u003cp\u003e \u003c\/p\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 Grandchild 670 Features\u003c\/h2\u003e\n\u003ciframe src=\"https:\/\/www.youtube.com\/embed\/7HINQKfYTR4?si=pYI7_R6fxDdGUJwW\" 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\u003cp\u003e\u003cbr\u003e\u003c\/p\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_Grandchild_670_front_view_1.png?v=1771996925\" alt=\"Heritage Audio Grandchild 670 Vari-Mu 500 Series tube compressor front panel\"\u003e\u003c\/div\u003e\n\u003cdiv class=\"par-text\"\u003e\n\u003ch2\u003eThat Compressor Sound — Now in Your 500 Series Rack\u003c\/h2\u003e\n\u003cp\u003eThere's a reason engineers have been chasing the sound of classic Vari-Mu tube compression for decades. That effortless glue, the way it breathes with the music, the warmth it adds without ever sounding like it's doing anything at all — that's exactly what the Grandchild 670 puts in your hands, in a double-wide 500 Series module.\u003c\/p\u003e\n\u003cp\u003eTwo new-old-stock mil-spec 6BA6 tubes per channel and three custom-wound transformers give the Grandchild 670 the weight, depth, and character of the hardware that inspired it — built to Heritage Audio's exacting standards in their Spanish factory and priced for the real world.\u003c\/p\u003e\n\u003cp\u003eAs an authorized dealer, Pro Audio Reserve ensures your Grandchild 670 is a genuine Heritage Audio product backed by full manufacturer warranty and support.\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_Grandchild_670_rear_view_1.png?v=1771996926\" alt=\"Heritage Audio Grandchild 670 stereo tube limiter compressor module\"\u003e\u003c\/div\u003e\n\u003cdiv class=\"par-text\"\u003e\n\u003ch2\u003eProgram-Dependent Compression That Moves With Your Music\u003c\/h2\u003e\n\u003cp\u003eVari-Mu compression doesn't work like a VCA or FET — it listens. Gain reduction starts gently on small peaks and scales naturally up to brickwall limiting on the loudest transients, all without you touching a knob. Five selectable attack and release time constants let you tailor how aggressively the circuit responds, from barely-there bus glue to full, deliberate limiting.\u003c\/p\u003e\n\u003cp\u003eWhere most units bury the DC Threshold in an internal trimpot, the Grandchild 670 puts it right on the front panel. Dial in your slope continuously — from a silky smooth compression-to-limiting transition all the way to a harder, more pronounced knee — and hear the difference in real time.\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_Grandchild_670_rear_view_1.png?v=1771996926\" alt=\"Heritage Audio Grandchild 670 500 Series module installed in rack\"\u003e\u003c\/div\u003e\n\u003cdiv class=\"par-text\"\u003e\n\u003ch2\u003eTrack, Mix, Master — It Does All Three\u003c\/h2\u003e\n\u003cp\u003eThe Grandchild 670 isn't a one-trick compressor you pull out for specific sessions — it's the kind of unit that stays patched in because everything sounds better through it. Vocals sit more naturally. Drum buses breathe. Full mixes take on that cohesive, finished quality that used to require much more expensive hardware to achieve.\u003c\/p\u003e\n\u003cp\u003eA front-panel VU meter, On\/Bypass\/Off switch for instant A\/B, and a clean double-slot 500 Series format mean it integrates into your workflow without friction. Heritage Audio built this for engineers who take their sound seriously — and want the tools to match.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003ch3\u003eHighlights\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eVari-Mu tube stereo compressor\/limiter in a convenient double-wide 500 Series module\u003c\/li\u003e\n\u003cli\u003eTwo NOS mil-spec 6BA6 tubes per channel with three custom-wound transformers\u003c\/li\u003e\n\u003cli\u003eProgram-dependent gain reduction scaling from gentle compression to brickwall limiting\u003c\/li\u003e\n\u003cli\u003eFive selectable attack\/release time constants and front-panel DC Threshold for variable slope control\u003c\/li\u003e\n\u003cli\u003eVU meter, On\/Bypass\/Off switch, and robust build quality for reliable daily use\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eTechnical 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\u003eProcessor Type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eTube Vari-Mu Compressor\/Limiter\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\u003eChannels\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eStereo\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;\"\u003e2 x NOS mil-spec 6BA6 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\u003eTransformers\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e3 x custom-wound\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003eControls\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eInput Gain, AC Threshold, DC Threshold, Time Constant Switch\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\u003eTime Constants\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e5 selectable positions\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\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;\"\u003e20Hz – 20kHz (±0.5dB)\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\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003eBypass\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eOn\/Bypass\/Off Switch\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\u003eModule Slot Size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eDouble (2-slot)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e\u003cstrong\u003ePower Usage\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e±16V \/ 200mA per rail, per slot\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\u003eDepth\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003e7.08\"\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;\"\u003e2.46 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\u003eManufacturer Part Number\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ccc;\"\u003eGrandchild\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 Grandchild 670 500 Series Stereo Tube Compressor 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":48051750568091,"sku":null,"price":2299.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0646\/4031\/9643\/files\/Heritage_Audio_Grandchild_670_front_view_1.png?v=1771996925","url":"https:\/\/proaudioreserve.com\/products\/heritage-audio-grandchild-670-vari-mu-tube-compressor-500-series","provider":"Pro Audio Reserve","version":"1.0","type":"link"}