LED retrofits for burnt out VU meter lamps

[greenhorn]

I had ended up buying a Pioneer SA 606 with burnt out VU meter bulbs which the seller had claimed would be easily replaceable. My research had pointed me to the fact that the bulbs were rather inacessible - inside the VU meters themselves, and the bulbs were unavailable, with no approximate replacements (8V, 50ma)

Figured I'd do an LED retrofit. Bought warm white LED's to keep the authenticity - designing for 8V, 2 LED's and a 100 ohm resistor should keep current at around 10 mA.

The bulbs had only a yellow tint, but due to the yellowing of the reflectors and the plastics, the VU meters have a substantially more yellowish glow.
Snaps of the Work in process, and the final result. It's a bit more yellowish than the bulbs on my tape deck, but not unnaturally yellow.

 

[prosenjit]

great job..

 

[ukjeyaraj]

Amazing work. Looks very cool and nice.

 

[apk]

Looks very nice. Great job!

Nice to see another fan of UV meters! Both my power amp and tape deck have UV meters....

P.S - for a change you could try out green LEDs (similar to McIntosh)

 

[greenhorn]

nah. even though I dont look forward to opening it up again, if I do open it up again would be to clean the insides of the glass - my attempts to clear up the inside of the glass made it look worse - need to clean it with some microfibre cloth.
I'm interested in making them look stock. If i do change, I would replace one of the warm white LED's with a regular white LED to make it look less yellowish

 

[Hiten]

Nice work Greenhorn. Am guessing clear LED would tone down yellow tint. And for inside of the glass try polishing cream (like Min cream) don't know if they are still available.
regards.

 

[kanwar]

Greenhorn,

How about Blue Leds?

 

[greenhorn]

can be done. design for blue and white LED's are the same as all of them run around 3.2V.
they will look like this
PIONEER SA-706 PIONEER TX-606 - YouTube
you can fit red or green or any colour, but then the resistor values/number of LED's would change.
I used warm white to keep the original look

 

[greenhorn]

update. both the LED's died. So much for the longer life of LED's. I was running the current rather low, and yet this happens.
Any recommends on where to get something with longer life ?

 

[sarith]

update. both the LED's died. So much for the longer life of LED's. I was running the current rather low, and yet this happens.
Any recommends on where to get something with longer life ?

Something with longer life is a ? these days. If you can find the flat LED's (old ones), they seem to last more. I don't know if the flat ones are available as clear LED.

 

[greenhorn]

i replaced these warm white LED's with a pair of cool white LED's running at <5mA and they still started to flicker and die after a couple of months

What to do ?

 

[bhvm]

Something is wrong. LEDs do not fry in a couple of years unless something is wrong.
Are the LEDs being powered by VU meters themselves? I mean are they getting Bass peaks and so on?

I would suggest you use a 5050 12v LED strip (3 LED bunch shall suffice) and power it from a separate 12v transformer.

 

[greenhorn]

I suspect that this is because i trimmed the LED's and soldered them too close to their bases.
Planning to try some SMD LED's next.!

 

[newlash09]

Great job Greenhorn....

Something about VU meters gets me salivating. I love listening in a dark room, with just the hi-fi lit up. Would have loved some dancing VU meters to keep me company. Maybe someday, I'll get there

 

[greenhorn]

Newlash, nowadays you don't have to buy a full vintage amp to get into the vu meter club. There are Chinese vu meter kits available on eBay which can be up and running for very little money!

 

[newlash09]

Thanks a lot Greenhorn....

In fact I had considered importing a poweramp aluminimum case with 2 front mounted VU meters from aliexpress. Thought i'd place this under my actual amp, and use it to house all the additional cables etc, to give a clean look. Then after some reading about connecting those VU meters, quickly realized that it was well beyond my DIY skills.

And the biggest disappointment for me was that, I had to buy some kind of buffer, to prevent the amp output , driving the VU meters from distorting the sound from the speakers. Too much of physics for me

So dropped the idea completely :sad:

 

[jls001]

I suspect that this is because i trimmed the LED's and soldered them too close to their bases.

That's a doubtful reason. There are lots of applications where the LED leads are trimmed so that the flat of the LED sits flush with the circuit board, and they work for years without issues.

May be you could revisit the value of your current limiting resistor? There's some remote chance that more current than what you're intending to flow may be flowing.

 

[greenhorn]

I have used the same LED's @ around 15ma for my car numberplate lights, and they worked flawlessly for over a year ( didnt die, had to replace them because i got rear ended)
Benny's first DIY : LEDs on an Ikon - Page 6 - Team-BHP
the first version i used 10ma here, and the second version used <5, and they still died. This is the only reason i have ruled out the too much current angle (also checked the voltage across the load resistor - its as per calculations