Meters of 2205 Starting to Yellow

fas0latid0 · Oct 28, 2014

I have a MC2205 I am getting ready to take into the shop. I got the glass already, just need to source out the backgrounds for the meters, they have started to change colors over time. I called McIntosh they said that its $40 for each meter for the Plexi glass, which I am not sure if I need, does that sound about right? Wondering if this has happened to anyone else.

62caddy · Oct 28, 2014

Hmmm... not sure how new glass will help in this situation. :scratch2:

You should only need to replace the acetate gels that go between the glass and the meter housings. Never heard Plexiglas being used for this - maybe that's something new.

I would certainly not think new gels cost anywhere near $40...

fas0latid0 · Oct 28, 2014

Sorry I forgot to mention I am getting the front panel glass replaced, it is cracked.

He did mention something about acetate, I was talking to Brian. He quoted me $7 through email which I think sounds about right, but when I called to order the lady in parts said $40 for some sort of plexi glass that is used for the meters.

62caddy · Oct 28, 2014

Ya - I'd just get the gels from Ryan. That's what they originally came with.

clinic-audio · Oct 28, 2014

Hello fasOlatidO

1) you have to know what is behind the front glass :
-1 sheet of specific MCINTOSH blue plexi
2) behind the panel :
- one light chamber behind the meter (see my first picture)
- 1 blue plexi (another different one not identical to the first one)
- the end of the light box should be cleaned or better with an aluminium foil to better reflect the light coming from the bulbs (#1866)

view of the meter when the light is on (with bad colored film)

clinic-audio · Oct 28, 2014

view of the MC2205 meter with the right blue film

clinic-audio · Oct 28, 2014

view of the MC2205 meter with front glass in place

clinic-audio · Oct 28, 2014

Meter of MC2205 Starting to yellow

With the picture you posted , I think that the white material is burned behind the meters ....

I hope for you that the back of the meter is not burned !

See what happen inside the "light box" when lamps are over heating :thumbsdn:

c_dk · Oct 28, 2014

I concurr with Patrice, I think you have more issues than blue tint.

Patrice, with the ad hoc voltage conversions, do you often see bulbs that have run so hot?

clinic-audio · Oct 28, 2014

Meters of MC2205 Starting to yellow

Hello Chris

No , only wrong lamp does such drastic dammage

I saw so many meters dammaged by the wrong lamps .....:thumbsdn:

See one meter scale from MC2155 :no:

fas0latid0 · Oct 28, 2014

clinic-audio said:
Hello Chris

No , only wrong lamp does such drastic dammage

I saw so many meters dammaged by the wrong lamps .....:thumbsdn:

See one meter scale from MC2155

So what do I do? At worst what would I need? I guess I will take it into the tech and see what he finds then fix it from there.

c_dk · Oct 28, 2014

As shown in my from the bench post, the meter light cases get to be weaker than egg shell, fragile. Just replacing the light bulbs on this 40 year old amp can destroy them.....the post is of a MC 2125, but the MC2205 can be just as bad.

Make sure your tech has worked on them before......

CountD · Oct 28, 2014

Holy Moly, like everyone has said be careful with those meter cases. They'll break in a second and well you won't find replacements.

fas0latid0 · Oct 28, 2014

Ok so the plastic being burnt behind the meters is what is causing the redish tint? I should probably have the bulbs replaced as well, maybe an LED upgrade if they exist.

clinic-audio · Oct 29, 2014

Meters of MC2205 Starting to yellow

hello !

fas0latid0 the meters of MC2205 are not like MC2125 and 2155 ! see my picture , the "light box" is strong not in plastic or ebenoîd .

So nothing to fear regarding the body of the meters .

The brown color that you can see on your meters may come from the back of the meters . I don't think that the rear of the meter itself is dammaged .

Again see my picture you will understand how it is fitted

c_dk · Oct 29, 2014

You are of coarse correct Patrice......it is the mc2255 that went to the plastic meter light boxes......right?

When I was talking to Terry about the Mc2125 light boxes he was explaining to me how hot the lamps get when they get a tungsten (silver) coating inside the glass bulb. Makes sense to me....

clinic-audio · Oct 29, 2014

Meters of MC2205 Starting to yellow

Hello Chris

You are of coarse correct Patrice......it is the mc2255 that went to the plastic meter light boxes......right?

yes , they are . Here some pictures about MC2255 meters :yes:

MC7270 has the same "meter box" .....

CountD · Oct 29, 2014

c_dk said:
You are of coarse correct Patrice......it is the mc2255 that went to the plastic meter light boxes......right?

When is was talking to Terry about the Mc2125 light boxes he was explaining to me how hot the lamps get when they get a tungsten (silver) coating inside the glass bulb. Makes sense to me....

Yes, it was a Mc2155 that I did that had a meter box completely egg shell on me. Won't ever do that again. But then again, probably won't own one again.

Meters of 2205 Starting to Yellow

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