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Author Topic: Studer meter bulb replacement  (Read 4325 times)

Offline RogerD

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Studer meter bulb replacement
« on: May 13, 2010, 05:08:03 pm »
Hello,

I have a light out on my A820, so I tried to replace the bulb,but I'm having trouble with the white plastic tab. Is there a trick? As I don't want to break it. These are 15 years old and it has probably lost some flexibility. Anybody have a better experience.

Thanks,

Roger D.

Offline Ki Choi

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Re: Studer meter bulb replacement
« Reply #1 on: May 13, 2010, 09:13:45 pm »
Hi Roger:

Replacing VU meter bulbs on A810, A812, and A820 can be tricky when the white plastic covers had turned yellow in color and had become brittle.  You can easily break the latch tab trying to remove it from the circuit board.  So be careful.  I usually undo the one side first and gently push the tab over.

It is a good idea to replace both light bulbs on both VU meter assemblies all at one time while you have it disassembled since the working bulbs will eventually go out sooner than the new ones.

After replacing the bulbs, I usually file the circuit board down a little where it is making contact with the white plastic latch so that it will come out easier the next time (probably 10 years from now...)

Hope it helps.

Ki
Ki Choi

Offline ironbut

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Re: Studer meter bulb replacement
« Reply #2 on: May 14, 2010, 12:12:32 am »
Great stuff Ki!
You've turned into quite the Studer answer man which is absolutely fantastic.
Good advice on switching both bulbs there. It took me years to figure out that changing both headlights in my car when one goes out only makes sense.
steve koto
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Offline RogerD

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Re: Studer meter bulb replacement
« Reply #3 on: May 14, 2010, 08:34:03 am »
Hi Roger:

Replacing VU meter bulbs on A810, A812, and A820 can be tricky when the white plastic covers had turned yellow in color and had become brittle.  You can easily break the latch tab trying to remove it from the circuit board.  So be careful.  I usually undo the one side first and gently push the tab over.

It is a good idea to replace both light bulbs on both VU meter assemblies all at one time while you have it disassembled since the working bulbs will eventually go out sooner than the new ones.

After replacing the bulbs, I usually file the circuit board down a little where it is making contact with the white plastic latch so that it will come out easier the next time (probably 10 years from now...)

Hope it helps.


Ki


Thanks Ki,

Your always helpful and I appreciate it. I'll give it another shot.

Regards,
Roger


Offline stellavox

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Re: Studer meter bulb replacement
« Reply #4 on: December 30, 2015, 08:57:34 am »
Of course the bulbs on the two 812's I rebuilt were burned out.  Locating replacements at the time uncovered "exorbitant" prices on NOS units.  Have some experience with LED's, so replaced "them with those".  Found that Cree C535A-WJN-CU0V0231's (110 degree dispersion - available from Mouser) worked just fine.

Removed the bulb sockets and wired TWO LED's (in SERIES - works just fine) reusing certain of the existing bulb socket mounting holes.  Positioned the LED's as far apart as their leads would allow and (of course) pointing "forward". 

The "repair" provides plenty of illumination; no heat; BUT does look "whiter" (versus "amber") which could be a problem for purists - haven't looked to see if an amber LED is available - nor tried some kind of translucent "filter"

Charles   

Offline docb

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Re: Studer meter bulb replacement
« Reply #5 on: December 30, 2015, 11:29:45 am »
There was a standard for that buff color one sees on classic VU meters, but I can't seem to google it. The color temp of the meter lighting no doubt influenced the decision when it was established, and that light source would of course have used tungsten filaments. The spectral bandwidth of white LEDs is somewhat limited, and I don't think you will be able to match the color temp of the original tungsten filaments exactly. White leds in general are rather more blue than direct sunlight, up around 6000K - 6500K vs about 2700K for tungsten bulbs. Amber LEDs are pure yellow-orange, typically around 592 nM, which would probably be too intense yellow color-wise. What you might want is a warm white led, which is an attempt at matching the tungsten filament spectrum and typically around 2700-3000K.
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Offline c1ferrari

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Re: Studer meter bulb replacement
« Reply #6 on: March 25, 2016, 04:29:06 pm »

The "repair" provides plenty of illumination; no heat; BUT does look "whiter" (versus "amber") which could be a problem for purists - haven't looked to see if an amber LED is available - nor tried some kind of translucent "filter"

Charles   

I've recently sourced an A810 with the cooler than original light...I'm trying to work through it.  ;-)

Sam
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