DIY : Marantz LED kit for bargain

buzzz57

Marantz noob
DIY : Marantz LED kit for a bargain

Hi,

I'm quite new here. Last month, I have spent some nights looking for a LED kit that wouldn't be too expensive.
When I have seen the prices, I have decided to build my own kit.

First of all, I would like to tell you that I have neither particular electronic nor soldering skills.
I have just taken advantage of others' knowledge on the forum, and put it together.
Below is how I have done.

First step : defining the constrains
1) use the 8V AC power supply.
2) have no flickering due to AC.
3) keep the fuse lamp format to have no future impact
4) have the least components
5) keep the price low


For point 1, I have used the following topic :
http://mail.audiokarma.org/forums/showthread.php?t=119597
I have decided to stick to the circuit B : 1 LED, 1 resistor, 1 diode
The problem with this solution is the 50/60Hz flickering.


The solution to point 2 is the following.
Instead of using a single LED, I have doubled the components.
Which gives me the following schematic :
attachment.php

With that, you now have a 100/120Hz flickering, that is not noticeable by the human eye.


Now, points 3, 4 and 5 must be taken in account.
To achieve point 3, there is only 1 solution : using CMS LEDS. Standard LEDs can't go in the 6x30mm fuse lamp cartridge, or you have to leave the LEDs outside and it doesn't look very nice and professional.
I decided to go the CMS route.


For point 4, I have found a solution while browsing to find my CMS LEDs. I have come across a vishay CMS LED reference on Radiospares (a french Mousers.com equivalent). This LED is the VLMW41.you can find it on Mousers too under the reference 78-VLMW41R1T1.
Here is the technical sheet : http://docs-europe.origin.electrocomponents.com/webdocs/0e54/0900766b80e54154.pdf
With 2 LEDs put head to head, the schematic is now as follows :

attachment.php


This is equivalent to the previous schematic, but you now have only 3 components instead of 5.


Point 5 now.
Here is your buyers' list for a 2238B receiver (7 lamps) :
- 7 x 270ohms 1/4W resistors
- 14 x VLMW41 LEDs
- 7 x 26.99x6.34mm fuses

Next post : How to.
 

Attachments

  • Schematic B1.png
    Schematic B1.png
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  • Schematic B2.png
    Schematic B2.png
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Here is how to build your LED lamps.

No special competence is required. Just to be able to make quick and clean solders to avoid toasting your LEDs.
The necessary material is :
- a soldering iron (ideally with 2 heads : 1 fine, 1 large)
- a pair of pliers to hold hot stuff without hurting your fingers
- fine tin wire



1) heat each end of every fuses to dismantle them. The heat will melt the glue and the ends will come apart easily.
Don't worry about the glue that may remain on the ends of the glass piece. It won't affect the light transmission.
(pictures to come)

2) make an assembly of 2 LEDs. be careful to place the LEDs head to head (see the small notch in one of the corners)


3) solder the LEDs together


4) solder your resistor to 1 of the LEDs, and a wire to the other one.


5) Now, put your assembly in the glass sleeve and cut the resistors' wire to have the LEDs centered in the sleeve. remove the assembly from the sleeve


6) Melt a small amount of solder inside one end of your fuse.


Immediately put the resistor end of your assembly in the tin while it's melted. Be careful to put it in the middle of the fuse cap.

6) Put the sleeve in place. Cut the wire at the other end of your assembly.
Melt again a small amount of tin in the second cap. Put your assembly in the cap while the tin is melted.
You're done!


Enjoy your new cool blue backlighting !!!


PS : don't hesitate to replace the velum paper in front of the lamps if it's yellowish/brownish.
 
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That worked out well.

Did you try it with white LED's at all?

There are some points on the dial that are white with stock lamps.

Looks good though. Very even.

Rob
 
You could drill holes in the end caps for the leads to come through, put it together, solder it, and cut the leads.

Just a though.

Rob
 
There a guy on ebay making these same assemblies.Was tempted to get some for a SPEC 2.Not anymore..I have part numbers.:D
Thank you Buzzzzz..:thmbsp:
 
That worked out well.

Did you try it with white LED's at all?

There are some points on the dial that are white with stock lamps.

Looks good though. Very even.

Rob

Rob, I believe he used white LED's, the yellow filter is used to tame the blue down if I'm not mistaken.
 
Very nice LED fuse lamps.

1. In your schematic I see diodes 1N4004. Do you use them?

2. I doubt that 60 Hz flickering is noticeable by a human eye. Is that the reason you use two LEDs? Do you connect them in series?

3. SMD idea looks pretty cool. I first time see it here.

If regular round 5mm LEDs are too big for the glass sleeve, you can use regular round 3 mm LEDs. They should fit inside.
Besides, is using a glass sleeve really nesessary? Using end caps without the glass sleeve allows using regular 5 mm LEDs.

5 mm and 3 mm LEDs offers a lot of choices as to Color and Luminous Intensity. And they're very cheap.

4. So you used white LEDs. Do you concider other colors (blue)?

Great work, indeed!
 
That worked out well.
Did you try it with white LED's at all?
There are some points on the dial that are white with stock lamps.
Looks good though. Very even.
Rob
The LEDs are white. The white dots are barely visible on my last picture because of the view angle and the FOV, but they are white.

Nice work! How long did it take you to assemble 5 of them?
When I managed to find how to assemble them correctly, it took me about 1,5 hour to make the 7 lamps.
But at the beginning, I did it wrong and tried to put the LEDs in parallel and not in serie. When I tried the first lamp, it didn't work. It took me a quarter of an hour to detect my error. After that, everything went smooth.

Very nice LED fuse lamps.
1. In your schematic I see diodes 1N4004. Do you use them?

2. I doubt that 60 Hz flickering is noticeable by a human eye. Is that the reason you use two LEDs? Do you connect them in series?

3. SMD idea looks pretty cool. I first time see it here.
If regular round 5mm LEDs are too big for the glass sleeve, you can use regular round 3 mm LEDs. They should fit inside.
Besides, is using a glass sleeve really nesessary? Using end caps without the glass sleeve allows using regular 5 mm LEDs.
5 mm and 3 mm LEDs offers a lot of choices as to Color and Luminous Intensity. And they're very cheap.

4. So you used white LEDs. Do you concider other colors (blue)?

Great work, indeed!
1) No, because it's already included in the VLMW41 (look at the technical spec). In fact, I should modify my last schematic to make it more clear.

2) Unfortunately, here in France, it's 50Hz, and found the flickering very noticeable. That's why I put two VLMW41 in serie, head to head. This way, one LED is On for the high front, and the other one is On for the low front. --> 100 Hz.

3) Yes, I could use standard 3mm LEDs, but even if it goes inside the sleeve, it wouldn't face forward. It would illuminate the sides and not the dial. I doubt it would look OK. The VLMW41 has two advantages :
- I can make it face forward
- it has a wide view angle, which makes an evenly iluminated dial

I could remove the sleeve too, but my aim was to have a stock lamp for replacement. I have seen designs without the sleeve, but it looks very weak. What if you bend the assembly when you try to put it in the lamp support ?

4) The problem with colors other than white is that you have to compose with the original blue color from the dial itself. The resulting colors can only be green or purple if you use yellow or red LEDs.
 
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Thank you for your elaboration on my questions.

Diodes are already embedded into LED. Wow! That’s what I thought from your 2nd schematic, just want to make sure.

Of course, white color is good for Marantz. But, for instance, Sansui and Yamaha need some green LEDs.

So you remove matal caps from the glass by heating the caps with soldering gun?

Excellent design & implementation.
 
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I was lazy when I did my Sansui 3000A. Instead of sticking the LED bulbs in a stock-type enclosure, I just soldered the outside leads to the clip tabs. :D
 
If you are going to use two LEDs to knock the flicker down, you can use any SMD LED part if you wire them in opposite-polarity parallel. Then, you don't need parts with built-in protection diodes (and you don't need external ones), and this may broaden the part selection and perhaps lower the cost. The series connection is nice, though, as it does make assembly easier.
 
no real trick. use a flat head with your iron. To help contact and heat transfer, you can put a small amount of tin on the fuse end. The end should drop easily after a few seconds.
 
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