sentences:  In 2010, Ampeg introduced the Heritage Series line, manufactured in LOUD Technologies' facility in Woodinville, Washington, including the Heritage SVT-CL head and SVT-810E and SVT-410HLF cabinets.The updated head featured JJ-branded preamp and driver tubes and "Winged C" 6550 power amp tubes, all tested and matched by Ruby Tubes in California, along with a thicker 1.6mm two-layer printed circuit board with through-hole plating and increased copper weight.In May, 2018, Yamaha Guitar Group acquired Ampeg from LOUD Audio.