AKAI GX-625 - Arduino LM8529 IC Emulator with TM1637 Display to replace original - UK Vintage Radio Repair and Restoration Discussion Forum

Giuseppe_ · 6th Jan 2026, 8:17 pm

Hi everyone, I'd like to share a modification I made to the AKAI GX-625. Unfortunately, the display stopped working due to a shorted LM8529 IC that has been out of production for decades.

https://github.com/gldibella-maker/Arduino-LM8529-LM8523-IC-Emulator-with-TM1637-Display/tree/main

This project addresses the need to replace or emulate the functional logic of the LM8529 integrated circuit, a legacy controller originally used in audio/video equipment (such as tape recorders) for revolution counting and timing functions. The goal is to provide a software tool (an Arduino sketch) that allows technicians and enthusiasts to reconstruct the behavior of the original chip using an Arduino microcontroller and a 7-segment LED display driven by the TM1637.

DMcMahon · 9th Jan 2026, 2:54 pm

Hello Giuseppe and welcome to the Radio Forum.

Thank you for posting this, it is very good reference information.

I have a GX-625 and luckily the tape counter display is still working well.

I know really nothing about Arduino, but your link information will be very valuable if I ever have to fix my display.

David

6th Jan 2026, 8:17 pm	#1
Giuseppe_ New Member Join Date: Jan 2026 Location: Valverde, Catania, Sicily, Italy. Posts: 1	AKAI GX-625 - Arduino LM8529 IC Emulator with TM1637 Display to replace original Hi everyone, I'd like to share a modification I made to the AKAI GX-625. Unfortunately, the display stopped working due to a shorted LM8529 IC that has been out of production for decades. https://github.com/gldibella-maker/Arduino-LM8529-LM8523-IC-Emulator-with-TM1637-Display/tree/main This project addresses the need to replace or emulate the functional logic of the LM8529 integrated circuit, a legacy controller originally used in audio/video equipment (such as tape recorders) for revolution counting and timing functions. The goal is to provide a software tool (an Arduino sketch) that allows technicians and enthusiasts to reconstruct the behavior of the original chip using an Arduino microcontroller and a 7-segment LED display driven by the TM1637.

9th Jan 2026, 2:54 pm	#2
DMcMahon Dekatron Join Date: Apr 2019 Location: Worthing, West Sussex, UK. Posts: 7,279	Re: AKAI GX-625 - Arduino LM8529 IC Emulator with TM1637 Display to replace original Hello Giuseppe and welcome to the Radio Forum. Thank you for posting this, it is very good reference information. I have a GX-625 and luckily the tape counter display is still working well. I know really nothing about Arduino, but your link information will be very valuable if I ever have to fix my display. David