mac500's

[Matt]

opur mac500's are getting old and noisy now, and the lamps are starting to get unbalanced in terms of output (one is darker than the other).

I have had a look at the lamp hours on the display and one says around 1800hours and the other way over 2500, and I know its definitely not recommended to run in the extra 25%(?) of life they have, but I am not sure wether the counter has been reset when a new lamp was installed - they also take one heck of a time to strike from cold (timed it, and it took 7 minutes on one and 10 on the other respectively), can anyone offer me advice on what they think, and possibly tell me the type of lamp they use for my future reference when purchasing some more - and advice on installing might help :(

 

cheers.

 

Matt.

[gareth]

They take an MSR 575w lamp with a GX9.5 base. Handling requirements are pretty much the same as ordinary TH lamps. Let them cool before taking them out of the fixture, don't touch the glass envelope, give them a quick wipe down with the solvent-soaked wet-wipe that's normally included with the lamp after you install it, etc. And once you've changed the lamp, take a few minutes to align it properly - it makes a big difference.

 

When you talk about the time they take to strike .... do you actually mean the time to strike (i.e. for the lamp to strike), or the time for them to come up to their normal operating colour temperature?

[SparkySteve]

I would suggest maybe just cutting your losses and installing new lamps in both, that means you should theoretically have balanced light output from both macs and therefore a matching pair. as long as you do what Gareth suggested and align it properly - it makes a hell of a difference. while your at it I would also suggest using a computer screen wipe and cleaning the lens, colours and gobos... for the hard to reach ones use a handle of a teaspoon and cover it with the wipe, its amazing everytime I do it how much ##### people allow their macs to work with and normally they don't notice... think I might pop over to pet hates now. Grrr! :(

[Matt]

yeah I have recently been through them with a fine tooth comb and cleaned them, the amount of crap that came from it (bought them ex-hire so...)

 

I was planning to replace both at the same time - pointless otherwise, and what I mean by strike is to actually turn on, it only takes them about 3 minutes once they are on to get to their brightest.

 

Matt.

 

ps - I guess it tells you how to align the lamp in the manual right. not that we have it, I'll have to do a download sometime.

[peter]

To align the lamps, its simply a case of pointing the mac at an appropriately flat surface and using an alen key on the 3 'knobs' at the back. One moves the lamp forwards and backwards, one up and down and the other side to side. Experimenting with the alignment should give you the maximum brightness.

 

Peter

[Matt]

so its just a matter of experimenting then, should I try that anyway, at the moment just to try and get that extra bit out of them, coz they have been bashed around a bit - bloomin' kids playing around with the flightcases in the hall, using them as race cars - caught them red handed so to speak, they got dt's for it, I love my job sometimes.

[peter]

It might be worth a go, however be careful. Over-old lamps can shatter and take out some of the internal components. If I were you, I'd replace the lamps ASAP.

 

FYI, I've always found the Phillips Broadway MSR-575-2 to be fine in Mac500s. Be careful about going for cheaper lamps though - have heard some horror stories, although the latest ones related to Mac 2000 lamps.

[gareth]

what I mean by strike is to actually turn on, it only takes them about 3 minutes once they are on to get to their brightest.

Presumably you've got SPEC/ALON set to ON? This function has a time delay between power-on and lamp striking - the length of the delay is dependent on the DMX address, the higher the address the longer the delay. This is to prevent problems with a large rig of units all set to ALON and all striking at exactly the same time if powered up in unison (this would cause a big surge of power - a striking Mac pulls about 4 times the current of a running Mac).

 

So if this is the cause, and you want them to strike sooner, you have two options - either set them to a lower DMX address, or set SPEC/ALON to OFF and send a lamp-on command from the desk.

[Matt]

they both strike in roughly the same amount of time regardless of the DMX address, wether its 490 or 1

[peter]

Its a long shot, but what software are they running? Its possible the lamp on timing was added in a later version of the 500 software.

 

Anyway, try relamping them and let us know if you have any more problems.

[cmck]

I would strongly reccomend changing both lamps ASAP. If you think they were full of crud when you bought them, stick around and wait for a lamp to expolde. Not only powdered quartz, but broken dichroics and reflectors.

 

Seriously though, the manufacturer's rated life is just that, the expected life of the lamp. If you exceed, you run the risk of explosion, or as Phillips put it "energetic decomposition".

When looking at lamps, consider the Phillips MSR 575 or the Osram HSR 575. Don't consider any others, they will be inferior. Depending what you are doing with them think about the following. The Osram lamp starts out at a higher colour temperature and increases in colour temp through its life. This gives you a bluer light which creates an apparently brighter light, stress on the apparent!! This also gives you chunkier blues from the colour wheel, but less grunt out of reds and ambers. A decision on how you run these units and what colour temp the rest of your rig is.

 

Good Luck,

Chris McK

[Neil Frazer]

Seriously though, the manufacturer's rated life is just that, the expected life of the lamp. If you exceed, you run the risk of explosion, or as Phillips put it "energetic decomposition".

When looking at lamps, consider the Phillips MSR 575 or the Osram HSR 575. Don't consider any others, they will be inferior.

Don't exceed the rated life of the lamp. you run the risk of the lamp exploding and quite frankly the output is cut in half by the end of its life. The new GE CSR575 lamps are just as good as the Phillips and Osram ones. And they are cheaper.

[Matt]

well we are kinda using them between rock concert type things and drama productions, so I'd rather stick with the phillips, more of a steady colour throught life, though the reds do seem a bit weak.

 

though the other guy there (see the post of mine in the random useless facts thread) says that it aint worth changing both coz its used in a school environment, and with the way he chucks them around I doubt they will last any longer than a month... any way to quieten the gears down, they are getting a bit too noisy now.

[Tomo]

Lubricate the gears.

 

Very light grease is probably best, as I think sewing machine oil is probably not suited to the high temps in those things.

[Ike]

GE CSR575 lamps are, IMHO, better than Phillips ones, I just want to stress the point of replacing lamps at or before the rated life, we have just had a mac2000 prety much destroyed by a lamp going pop.