View Larger Image Fosi Audio BT20 A Pro with Burson V7 Opamp They sound wonderful, the soundstage is much wider and the bass reaches down further. Awesome! By Sales Burson|2024-03-25T14:53:27+11:00March 25th, 2024|V7 SS Opamp|Comments Off on Fosi Audio BT20 A Pro with Burson V7 Opamp Share This Story, Choose Your Platform! FacebookXRedditLinkedInTumblrPinterestVkEmail