JBL GTO 1004 600 Watts 4-Channel Full-Range Amplifier – NTC Tech。GTO1004 | Full-range amplifier for your car audio system。JBL GTO 504 4-Channel Car Power Amplifier : Amazon.nl: Electronics。GTO1004 | Full-range amplifier for your car audio system。JBLのGTO1004 4chアンプですJBLシリーズが好きで使ってました