GUITAR COMBO AMPLIFIER VOX AC15C1X Guitar Amp. The Blue Alnico speakers manufactured by Celestion are especially a great match for the AC30. They have reigned as the standard combination since the VOX brand was established. Now a model with these Blue Alnico speakers is available in the AC15 series. - Combo amplifier for 15 W tube guitar. 2 Celestion Blue Alnico speakers from 12 to 16 Ohm. Valves: 3 x 12AX7 (previous) and 2 x EL84 (stage). Jack, Normal, Top Boost and Footswitch inputs (VFS2A optional). External speaker and extension speaker outputs. Size: Width 602 mm x Depth 265 mm x Height 556 mm. Weight: 22.6 Kg.