In a nutshell:

• For the Amstrad / Schneider CPC range of 8bit home computers
  
• Made possible by sponsoring and initiative from the one and only, legendary Future Man - TFM! https://futureos.cpc-live.com/
  
• Exclusive Limited Edition - by invitation only
• RSX ROM, software suite, and manuals by TFM
  
• Hardware & firmware bv LambdaMikel 
  
• Github: https://github.com/lambdamikel/LambdaSpeak-FS

Features: 

• Perfect speech synthesis: Epson S1V30120-based natural speech 
• DECtalk & Epson speech synthesizer modes
• English & Spanish speaking, different voices, DECtalk singing, ...
• MP3 player (from SD card)
• Battery-buffered Real Time Clock with thermometer
• Audio routing options for left / right stereo channel mixing & assignment:
  Audio from CPC speaker or external amplifier
• High quality Amdrum PCM sample playing mode:
  at least Digiblaster quality
• 70 new RSX commands for BASIC
• CP/M support (speech, real time clock)
• UART / Serial Interface up to 115200 Baud
• MIDI IN and OUT
• 8 easy to control GPIOs with LED Segment Bar for lightshows etc.
• FutureOS support
• 2 DKSs of software
• Users Guide & Technical Reference Manual available
• MX4 Connector
• Help & Support by TFM & LambdaMikel
• Open Source

Schematics

BOM

Resistors

• R7: 2k; note: must match D1 LED!
• R1, R3, R4: 10k
• R5: Jumper Wire
• Rn: 9pin Resistor Array / Network, A102J

Potentiometers / Trimmers:

• RV1: 100 Ohm (Code 101)
• RV2: 50k Ohm (Code 503)

Capacitors

• C1, C2: 22 pF (Code 220); note: these must match Q1!
• C3: 68 nF (Code 683)
• C5, C6, C7, C8: 100 nF (Code 104)
• C9, C10: Jumper Wire

ICs

• U1: GAL 22V10(B,D)
• U2: 74LS374
• U3: 74LS244
• U4: ATmega 644-20PU
• Optional: DIL sockets for ICs (I recommend to use a socket at least for U4, to allow reprogramming)

Misc

• CPC Connector: 2.54mm 2X25 50 Pin Right Angle Male Shrouded PCB Box Header IDC Connector
• Q1: 16 MHz Crystal
• SW3: 8 Position DIP Switch
• D1: Activity LED
• J8: 8 Segment LED Bar Display
• J2, J3: 2.54mm Pitch 8 Pin Single Row Straight Female Header Socket Connector for Arduino Shield (mikroBUS connector)
• J7: Breakable Single Row Arduino Pin Headers
• J4, J5: Mini Stereo Audio Sockets
• J1: Optional Barrel Jack Power Connector

Modules

• J2, J3: TextToSpeech board
• MP3 / UART: MP3 UART Module
• RTC / I2C: RTC IIC Module
• CR2032 3V Battery for RTC Module
• Mini SDCard for MP3 Module
• Mini Stereo Audio Patch Cable

Assembly Tipps

• Don't forget the decoupling capacitors (104's) under the ICs!
• If you are going to socket the ICs, then you will need to cut out the middle struts from the DIL sockets to accomodate them.
• Use a fine side cutter to cut off the SQW and 32K pins from the RTC module

Videos