Product Info. The TTS Sound Decoder - 'Britannia' Class supports both long and short decoder addresses and features adjustable acceleration and deceleration options as well as 2 sound channels for allowing the play of full locomotive sounds such as bells, wagon couplings and brakes. When operated via F0 on the controller, this decoder has the ability to support directional rear and front lighting - dependent on if the locomotive has lighting features. Motor current: maximum continuous- 500mA; Motor current: peak- 1.amp (no function load); Function output current maximum- 100mA (unprocessed).