Heritage Audio HERCHILD Next Gen Model 670N Vari-Mu CompressorsSomething only heritage audio could achieve Four years ago, Heritage Audio revolutionized the pro audio community by introducing the HERCHILD Model 660 and 670, a surgical recreation of the legendary Fairchild Model 660 and 670 by using authentic NOS tubes, carefully designed transformers and nailing the look and feel of the revered originals. Two years ago, Heritage Audio shook the pro audio community yet again by introducing the GRANDCHILD 670 500,