So some of you have seen the awesome BMoney Victor M70/M75 project. I tried to highlight the tuner conversion in that thread but seems the interest in the LED mod overshadowed the tuner conversion, so I guess this one deserves it's own thread.
JVC RC-M70 LED upgrade project and custom latching module
As installed from the factory, the JVC RC-M70 boombox uses a single incandescent bulb installed at the right side of the tuning dial. The result is a dial that is not very bright and lights unevenly across the tuning screen window. The meters, being factory unlit, remains dark. As I'm always interested in improvement and in "doing it right", I've decided to modify the boombox so that the dial will light with enough intensity to be useful. The meters should also be illuminated so that they can be of value when trying to center the tuning frequency in the dark. Once that is done, I will install a superduper custom built module to handle the lamp switching responsibilities. A single transistor solid state switch will handle the switching while a 4013 intergrated circuit chip will handle the logic needed to control the switch. The original mechanical switch is retained to best retain the look and feel of a factory installation, and also allow the owner to revert back to stock in the future if desired, although to be honest, after you see the result, it would seem silly to want that. The purpose of this additional module is to allow the lamps to remain illuminated after removing your finger from the switch. The factory switch is a momentary one and needs to remain depressed to illuminate the dial. With my module, you can press the switch once and the lamps will remain lit. Depress again to extinguish it.
FACTORY STOCK LAMPS
[youtube]uogvHKEMW48[/youtube]
AFTER UPGRADE
[youtube]sxSnz8vM9gg[/youtube]
CLOSEUPS OF WHAT IT LOOKS LIKE with BLUE LED'S:
THE UPGRADE:
HOW TO DO IT:
The LED's themselves simply replace the original incandescent bulb which from the factory, mounts in a rubber grommet. As led's should last the life of the boombox, they can be set in place with hot melt glue, which is strong enough to hold securely, yet can be removed if necessary albeit with a bit of work. Additional led's are placed on/near the meters and affixed in the same manner. It is recommended that you take this time to clean the tuner dial before proceeding with the upgrade. Over time, it is not uncommon for unsightly dust, dirt, grime, bugs to accumulate behind the dial. This is very unsightly, especially when the dial is brightly illuminated. I did not photograph the LED's set in place, but the following videos show how the module was created, how the LED's were installed, and the actual testing of the LED's as well as the module.
INSTRUCTIONAL VIDEO (PART A)
[youtube]ojVs7qJ3M6I[/youtube]
INSTRUCTIONAL VIDEO (PART B)
[youtube]zuy4AmwYUtg[/youtube]
THE MODULE: I found a perfect spot on the chassis behind the front cabinet to mount it, via standoffs and stainless nyloc screws.
THE SWITCH: The small circuit board below the meters supply power to the bulb. It receives a 12volt regulated supply from the mainboard. The mechanical switch above the meters with the white/brown wires is the actual lamp switch. It will be rewired so as to provide the new module a trigger. Basically, each application of the switch will send one trigger pulse to the new module which will take over the actual switching responsibility from the mechanical switch.
INSERTING CURRENT LIMITING RESISTORS INTO THE CIRCUIT: As the new LEDs require significantly less operating voltage compared to the original incandescent bulbs, dropping resistors are installed inline and embedded in the supply wires to the leds. I spliced the resistors by wire wrapping them into the supply cables, then soldering and finally protected them by encasing them in heat shrink tubing.
THE CIRCUIT: This is the design of the circuitry I used for the module. There are many ways to build one, and this one works good for me. Anyone that want to build their own, and wants a high-resolution image of my circuit, send me a PM. A full size schematic is too large to insert here.
KIT FOR SALE:
You can build your own using the schematic or your own design. But for those that would prefer not to collect the necessary parts, and assemble/test the kit, you can order a "kit"; module assembled, ready to install from me for $39 + shipping. It will come with instructions and lead time is currently about 1 week. Even though my modules are assembled and tested before shipping, installation still requires soldering skills and an installer comfortable working on boomboxes. The one pictured here is a pilot prototype, built specifically for BMoney. Subsequent ones might appear slightly different but will be functionally identical. YES, it can be installed in any boombox with small modifications but in kit form, it was designed for the M70 or it's equivalents. It comes with mounting hardware. What I'm selling here is the switching module, since I'm presuming that the installer possesses the expertise to retrofit their own lighting solution, whether it is to keep the lamps factory stock or to install LED's of their choice. Therefore, the kit does not come with lamps. However, if LED's are desired, I can add a pair of ultrabright LED's as well as a pair of super low profile LED's for installation over the meters and the necessary dropping resistors as well. Add $6 for just the LED's and resistors or add $10 to the kit for pre-wired (pigtailed) LED's with harness and resistors preinstalled, heatshrink insulated). Fatdog has already ordered 1 kit. I have 3 more ready to go. Subsequent ones will require a delay as I will need to build more.
THIS module is not boombox specific. However, since every boombox uses a different lamp switching design, the way to implement this into your boombox could vary. It really depends upon how the lamp is switched. ANY boombox that has a separate switch (like on the M70) can use this design. If your design uses a switch soldered onto the PCB, then it will be necessary to determine whether the switch is a single purpose switch, or a multi-pole, multi-purpose switch. Basically, if the switch shorts to ground, then this module is a drop in with minimal work required. If the switch supplies V+, and it's switch/pole can't be easily isolated to switch to ground, then the simplest way to use my module is to add an extra mini relay (I can provide). The relay can be triggered by the V+ and the contacts wired to trigger to ground. If all this sounds like foreign language to you, simply send me a PM and questions re: your model.
JVC RC-M70 LED upgrade project and custom latching module
As installed from the factory, the JVC RC-M70 boombox uses a single incandescent bulb installed at the right side of the tuning dial. The result is a dial that is not very bright and lights unevenly across the tuning screen window. The meters, being factory unlit, remains dark. As I'm always interested in improvement and in "doing it right", I've decided to modify the boombox so that the dial will light with enough intensity to be useful. The meters should also be illuminated so that they can be of value when trying to center the tuning frequency in the dark. Once that is done, I will install a superduper custom built module to handle the lamp switching responsibilities. A single transistor solid state switch will handle the switching while a 4013 intergrated circuit chip will handle the logic needed to control the switch. The original mechanical switch is retained to best retain the look and feel of a factory installation, and also allow the owner to revert back to stock in the future if desired, although to be honest, after you see the result, it would seem silly to want that. The purpose of this additional module is to allow the lamps to remain illuminated after removing your finger from the switch. The factory switch is a momentary one and needs to remain depressed to illuminate the dial. With my module, you can press the switch once and the lamps will remain lit. Depress again to extinguish it.
FACTORY STOCK LAMPS
[youtube]uogvHKEMW48[/youtube]
AFTER UPGRADE
[youtube]sxSnz8vM9gg[/youtube]
CLOSEUPS OF WHAT IT LOOKS LIKE with BLUE LED'S:
THE UPGRADE:
HOW TO DO IT:
The LED's themselves simply replace the original incandescent bulb which from the factory, mounts in a rubber grommet. As led's should last the life of the boombox, they can be set in place with hot melt glue, which is strong enough to hold securely, yet can be removed if necessary albeit with a bit of work. Additional led's are placed on/near the meters and affixed in the same manner. It is recommended that you take this time to clean the tuner dial before proceeding with the upgrade. Over time, it is not uncommon for unsightly dust, dirt, grime, bugs to accumulate behind the dial. This is very unsightly, especially when the dial is brightly illuminated. I did not photograph the LED's set in place, but the following videos show how the module was created, how the LED's were installed, and the actual testing of the LED's as well as the module.
INSTRUCTIONAL VIDEO (PART A)
[youtube]ojVs7qJ3M6I[/youtube]
INSTRUCTIONAL VIDEO (PART B)
[youtube]zuy4AmwYUtg[/youtube]
THE MODULE: I found a perfect spot on the chassis behind the front cabinet to mount it, via standoffs and stainless nyloc screws.
THE SWITCH: The small circuit board below the meters supply power to the bulb. It receives a 12volt regulated supply from the mainboard. The mechanical switch above the meters with the white/brown wires is the actual lamp switch. It will be rewired so as to provide the new module a trigger. Basically, each application of the switch will send one trigger pulse to the new module which will take over the actual switching responsibility from the mechanical switch.
INSERTING CURRENT LIMITING RESISTORS INTO THE CIRCUIT: As the new LEDs require significantly less operating voltage compared to the original incandescent bulbs, dropping resistors are installed inline and embedded in the supply wires to the leds. I spliced the resistors by wire wrapping them into the supply cables, then soldering and finally protected them by encasing them in heat shrink tubing.
THE CIRCUIT: This is the design of the circuitry I used for the module. There are many ways to build one, and this one works good for me. Anyone that want to build their own, and wants a high-resolution image of my circuit, send me a PM. A full size schematic is too large to insert here.
KIT FOR SALE:
You can build your own using the schematic or your own design. But for those that would prefer not to collect the necessary parts, and assemble/test the kit, you can order a "kit"; module assembled, ready to install from me for $39 + shipping. It will come with instructions and lead time is currently about 1 week. Even though my modules are assembled and tested before shipping, installation still requires soldering skills and an installer comfortable working on boomboxes. The one pictured here is a pilot prototype, built specifically for BMoney. Subsequent ones might appear slightly different but will be functionally identical. YES, it can be installed in any boombox with small modifications but in kit form, it was designed for the M70 or it's equivalents. It comes with mounting hardware. What I'm selling here is the switching module, since I'm presuming that the installer possesses the expertise to retrofit their own lighting solution, whether it is to keep the lamps factory stock or to install LED's of their choice. Therefore, the kit does not come with lamps. However, if LED's are desired, I can add a pair of ultrabright LED's as well as a pair of super low profile LED's for installation over the meters and the necessary dropping resistors as well. Add $6 for just the LED's and resistors or add $10 to the kit for pre-wired (pigtailed) LED's with harness and resistors preinstalled, heatshrink insulated). Fatdog has already ordered 1 kit. I have 3 more ready to go. Subsequent ones will require a delay as I will need to build more.
THIS module is not boombox specific. However, since every boombox uses a different lamp switching design, the way to implement this into your boombox could vary. It really depends upon how the lamp is switched. ANY boombox that has a separate switch (like on the M70) can use this design. If your design uses a switch soldered onto the PCB, then it will be necessary to determine whether the switch is a single purpose switch, or a multi-pole, multi-purpose switch. Basically, if the switch shorts to ground, then this module is a drop in with minimal work required. If the switch supplies V+, and it's switch/pole can't be easily isolated to switch to ground, then the simplest way to use my module is to add an extra mini relay (I can provide). The relay can be triggered by the V+ and the contacts wired to trigger to ground. If all this sounds like foreign language to you, simply send me a PM and questions re: your model.
Having to hold a button down just to have some light is LAME. 
AND I'd highly recommend the use of LEDs with this kit. 
So c'mon guys...buy the kit...support the development! 
.