Little Dot MKIII case discoloration

When metal turns color, it usually indicates a heat problem. How hot does it feel after running all day?

I have mine for a bout 6-7months and can see no discoloration at all.
I would first ask david about if i where you, before attempting anything.

No issues here either, bought it used and it seems like its one of the earlier releases and its in fine shape!

Edit:

Forgot to mention that this thing gets tons of usage due to living in a Japanese apartment and not being able to crank up the tunes on my Paradigm Titan speakers.

Pics?

My LD MKIII has that gold discoloration as well. It is as you describe: more like a fading of the black, rather than a pure gold color. For me, it's not evenly faded around the amp...the gold color is somewhat "rippled" looking, and is more visible on the right side of the amp (while looking at the front plate) than the left.

I bought the amp in early June from a fellow Head-fi member, who had it for two years before that (and used it quite regularly), and the discoloration was there when I got it. It has not gotten noticeably worse since I've had it (if at all).

As far as temperatures are concerned, I have been running it for the past 2.5 hours or so with ef95 driver tubes, and the metal chassis is warm, but not too hot. I can touch it and hold my hand there without any discomfort.

I took some pictures of it this evening. It's somewhat difficult to see the discoloration, because it varies based on the lighting. Is this the effect you are seeing?

I'd rule out heat as the entire chassis has this effect.

I've done a little digging. It seems that black anodized aluminum (which I believe is used for the LD MKIII chassis) can indeed fade to bronze/gold (clearly, as we are observing it). Its resistance to this effect is based on:

1. The quality of the dye seal
2. Exposure to UV lighting (more exposure --> more fading)
3. Temperature (hotter --> more fading)
4. "Over-the-counter ammonia-based cleaners" (I hope no one is using those!)
5. The light-fastness of the dye

It is possible that the fading we have observed is due to a poorly sealed anodize job, but given that not everyone has observed this effect, I'm going to guess that either they've changed the process or that the fading is caused by the other factors given above. Mine had faded before I got it, so I cannot confirm this.

The finish doesn't bother me personally, as it's difficult to see the fading except in the right light. You might want to talk to David and see what he says about restoring the black finish...he might have a solution (or at least might be able to tell you about the heat-safe-ness of spray-painting it black). Feel free to use my photos, if it would save you the trouble of bringing your amp home from work.

Cheers.

Edit...my sources:
Type II black anodizing discoloration (gold)
Black anodize turning bronze color

Another edit: I'm fairly certain now that the discoloration, at least in my case, is from the UV radiation from the sun. As I mentioned, the gold color is more present on the right side of my amp than the left, and after looking at it some more, I've noticed that the gold does extend across the top of the chassis from the right to the left, except immediately to the left of the tubes and the transformer. These must have blocked the sunlight from those areas, leaving them the original color.

DO IT! A firetruck-red LD would look sick

Ahh good, glad to hear your confirmation of the issue...and David's fixes to it.

This might be a strange suggestion after this discoloration problem, but why not coat it...bronze?

A nice, even bronze, of course.