Hello! This is a simple tutorial for MOD/Upgrade your ACE 250 with Ground Ballance control, Volume control and LCD Light.
Step 1: List of Materials
1) 30 Watt Soldering Iron (Flux & Solder)
2) Some insulated Wire for cnnection
3) Hot Glue Gun or other elastic glue but NO! SuperGlue
4) 1 x 1K Potentiometer
5) 1 x 20K Potentiometer
6) 1 x Mini Swich
7) 1 x SMD Led (mine is RGB led and only blue and green are connected)
8) Mini 20K SMD Pot (the one that you will remove from PCB)
9) Drill (4,5mm and 6,5mm) for pot and swich holes
10) Needlenose Pliers
11) Philips Screwdriver
Step 2: Teardown and Makeing the Hole for Ground Ballance
Teardown your ACE, measure and mark the spot (See the Picture) for the first hole (6,5mm diameter) This will be the spot for Ground Ballance Pot.
Step 3: Make Room for the Second Pot (Volume)
Use pliers to break the right wall (See Picture) to make room for the second Pot.1K Ohm (Volume)
Step 4: Measure,mark and Drill the Second Hole for Volume Pot.
After you make room for second pot, measure,mark and drill the second hole (see 1st & 6th Pic)
Step 5: Solder Ground Ballance Pot and Wires, Glue the LED in Place (See Pics and Description)
Desolder and remove VR Pic.1 (be careful to NOT damage the PCB leads) Then use 3 x 20cm long wires or cable with 3 wires, solder one end on PCB then insulate with hot glue and other on 20K Pot leads (See Pic.5)
Solder 2 wires on SMD LED (See Pic.2) then use some hot glue to keep in place on LCD(See Pic.3)
Solder one wire from LED on center lead of 20K VR (See Pic.2) and one wire to one of the to remaining VR leads (See Pic.2)
Step 6: Volume Pot Install
See description in every Pic.
Step 7: Mount G.B. Pot, Mount LED Swich, Connect Audio Wires, LED Wire to Swich and to Batt.
See Pic description. Check all the connections to be strong and insulated and put everything.
If you have questions ask and i will replay soon.
I hope this is useful.