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nathanscribe
Silver Member
United Kingdom
376 Posts |
 Posted - 03/28/2009 : 22:13:13
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If anybody has access to service notes/schematics for the Boss KM-60 mixer (and/or the KM-6) I'd be very grateful for a copy.
Failing that, if anyone knows what kind of bulbs they are that fit behind the VU meters, that'd be useful info.  |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 03/29/2009 : 15:53:00
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Hi nathanscribe
If you can remove the globes, they will generally have some writing on them,
indicating some voltage and current rating.
If that fails, get out a multimeter and measure the voltage across,
the terminals of the globe.
Test with both DC and AC settings,as sometimes they run these globes from an AC supply.
Post some pics, with a rule/ruler for size reference.
Most times these are either 6V or 12V lamps, unless they are of the miniature (grain of wheat) types.
With a bit of head banging  , we should be able to help you sort out the globes.
About 3 years ago, I replaced all the globes in a RAM 16 Channel desk for a good friend of mine.
Sometimes they will run a 12V or 14V globe on 6V to 10V to give it a duller more orange glow, nice for the back of a vintage VU meter.
Regards Dr. Bob 
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nathanscribe
Silver Member
United Kingdom
376 Posts |
Posted - 03/29/2009 : 15:56:59
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Hi Dr Bob.
I hope they're not 12V, because I measured across the leads and the meter said 50V DC! I'm guessing they're DC as the wires that supply power to them come right after the power supply recification diodes.
There are two lamps in series, and a 470 Ohm carbon comp resistor (looks like .5W type).
I'll take a photo shortly and post it. |
Edited by - nathanscribe on 03/29/2009 15:59:47 |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 03/29/2009 : 16:11:28
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quote:
Originally posted by nathanscribe
Hi Dr Bob.
I hope they're not 12V, because I measured across the leads and the meter said 50V DC! I'm guessing they're DC as the wires that supply power to them come right after the power supply recification diodes.
There are two lamps in series, and a 470 Ohm carbon comp resistor (looks like .5W type).
I'll take a photo shortly and post it.
Hi nathanscribe
They might be 24V golbes in series, which=48V
and then the 470 res, in series with the lot, to drop the other few volts.
My vintage, no name mixer, the stickers fell off.
has two 12V globes in series off the 24V split supply.
Check/Look with a magnifier, to see what's written on the metal bases of the lamps.
Regards Dr. Bob |
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nathanscribe
Silver Member
United Kingdom
376 Posts |
Posted - 03/29/2009 : 17:31:38
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Here's the rear of the VU meters, with burn marks visible where one of the bulbs has blown I reckon:
Here's the lamp PCB from the rear and the top:
And here's one of the lamps:
I couldn't see any markings of any kind on the bulb. The rubber collar had "103 S" marked on it, which is probably just a part code or something...
The lamp is about 10mm long and 4.5mm in diameter.
Would it be best to replace these with higher rated ones, so that if one fails, nothing gets fried? |
Edited by - nathanscribe on 03/29/2009 17:37:59 |
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nathanscribe
Silver Member
United Kingdom
376 Posts |
Posted - 03/31/2009 : 15:27:24
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Just received the service notes from Roland UK - and the bulb spec isn't listed! There's a part code, but no current/voltage ratings. Oh well. At least I was right about the resistor!
I bought a couple of 28V 24mA lamps from Maplin here in the UK... smaller physically than the old ones, so a little fudging to get them secure in the housing, but better than nothing. I'll fix 'em up tonight and see how they go. |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 03/31/2009 : 16:22:57
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Hi nathanscribe
Please PM me.
Regards Dr. Bob |
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nathanscribe
Silver Member
United Kingdom
376 Posts |
Posted - 04/01/2009 : 19:48:09
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Hi Dr Bob
Did you get the file?
Anyway, success!
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 04/02/2009 : 13:36:01
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quote:
Originally posted by nathanscribe
Hi Dr Bob
Did you get the file?
--- edited ---
 - Thanks, please check your Pm.
Regards Dr. Bob |
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Topic |
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KM-60 service notes
