You can see what is inside a BCR2000 here .
All rotary encoders have a string of leds as indicators. I had expected Behringer would have used prefab modules with switch and LEDs for this from Bourns or Avago and was surprised to see this was not the case. All rotary knob and led parts are built up from separate parts. The BCR2000 consists of an amazing number of parts.
The BCR2000 has a swichmode power supply an d 3 other PCB-s.
6 x HC574 "Octal Edge-Triggered D-Type Flip-Flops With 3-State Outputs"
4 x HC273 "Octal D-Type Flip-Flops With Clear"
6 x HC163 "4-Bit Synchronous Binary Counters"
1 x HC138 "3-Line To 8-Line Decoders/Demultiplexers"
2 x HC165 "8-Bit Parallel-Load Shift Registers"
1 x PDF OKI L671000: An ARM7TDMI CPU with full speed USB and UART, handy for MIDI.
1 x TMS 418160DZ, a 2 MB DRAM. The CPU apparently has DRAM Refresh logica on board.
1 x HCT04 "Hex Inverters"
1 x H11L1 "6-Pin DIP Schmitt Trigger Output Optocoupler" for the receiving side of the MIDI current loop.
1 x HCT245 "Octal Bus Transceivers With 3-State Outputs"