• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

MC2105 Replacement Bulbs

Motnick

Motnick

AK Subscriber
Subscriber
Hello. When I went through my MC2105 last year I replaced all four 1866 bulbs (058-014). Unfortunately, once I put everything back together I noticed that the face plate is not as bright as it should be. After studying the replacement bulbs some I have noticed that the new bulbs are shorter than the original bulbs. I suspect that this difference in length puts the filament closer to the lamps base, and that the filament is not reaching inside of the light diffuser far enough with the new bulbs to properly light the amplifiers front panel.

Has anyone else faced this issue before? Is it possible to get the longer bulbs somewhere?

index.php
 
Last edited:
Register to hide this ad
The brightness is affected by the location of the bayonet mount (which is easily moved).

See this explanation on my site: Link

Larry
 
VintageMac said:
The brightness is affected by the location of the bayonet mount (which is easily moved).

See this explanation on my site: Link

Larry
Click to expand...

Ahh yes. Thank you for the link! For the four meter bulbs I have done these steps and I have seen some improvement.

My issue is with the four lamps used to light the front panel. I think the location of these front panel lights is fixed?
 
Yes, that is correct. If the filament of the bulb does not line up with the center of the light diffuser, you will not get fully, brightly lit nomenclature.

Larry
 
I spoke with audio classics. They seemed familiar with the issue that I have, but they did not have any of the proper length bulbs to offer. Does anyone know of a source for the original length bulbs?
 
I bought 058-008 and 058-014 bulbs for my 2105 directly from McIntosh about a year ago, are these the ones you're looking for?
 
According to my service manual the lamps for “wording” #1866 are 058-014, and for the “meters” #1888 are 058-029.

index.php


The lamps that I purchased for the meters #1888 worked out because I was able to adjust the lamp sockets to the correct position to be in proper alignment with the meters light diffuser.

The lamps that I used for the front panel #1866 are too short. The filament does not reach far enough into the holes in the light diffuser panel behind the front glass.

I will give McIntosh labs a call when I get a minute to see what they have to offer.
 
Last edited:
If what was in there, were GE, then that of course would be likely the exact same replacement you seek, but I don't believe GE makes them anymore.
I could be wrong, but I think the Lamps I got that one time from WW Grainger were Phillips brand.
 
They aren't cheap, but according to c_dk (RIP) and clinic_audio the bulbs that McIntosh sells are still the good long-life bulbs and should last a long time like the originals, so that's what I bought.

I might have bought 058-029 also, I just don't see a bag in my McIntosh spares, maybe I didn't get extras.
 
markd51 said:
If what was in there, were GE, then that of course would be likely the exact same replacement you seek, but I don't believe GE makes them anymore.
I could be wrong, but I think the Lamps I got that one time from WW Grainger were Phillips brand.
Click to expand...

Philips makes some great bulbs, best if you can get long-life (not sure what is offered by Philips).
 
I was able to get in contact with McIntosh labs today. The parts dept. seemed familiar with the issue that I am experiencing with the #1866 lamps that I have. He wasn’t sure, but he seemed to think that the bulbs that they have in stock might also be shorter than the originals. I went ahead and ordered some 058-014 lamps from them anyway. Hopefully the McIntosh bulbs will be better than what I currently have installed. Guess I’ll find out once they arrive.
 
Motnick said:
Hello. When I went through my MC2105 last year I replaced all four 1866 bulbs (058-014). Unfortunately, once I put everything back together I noticed that the face plate is not as bright as it should be. After studying the replacement bulbs some I have noticed that the new bulbs are shorter than the original bulbs. I suspect that this difference in length puts the filament closer to the lamps base, and that the filament is not reaching inside of the light diffuser far enough with the new bulbs to properly light the amplifiers front panel.

Has anyone else faced this issue before? Is it possible to get the longer bulbs somewhere?

index.php
Click to expand...
I would contact Dave (dwojo69@msn.com)...he is a member here and has quality Lamp's/LED kit's.
 
The bulbs that I ordered from McIntosh labs arrived yesterday and I went to work this afternoon changing them out. The length of the filament on the Macintosh bulbs is longer than the 1866 bulbs that I had installed previously, but still shorter than the original bulbs. After studying things more today, I have come to the conclusion that the most important aspect when choosing a replacement lamp may be the distance between the top of the lamp globe and the pins that fit inside of the bayonet socket. This sets the overall distance that the lamp sticks out into the light diffuser panel. This distance was almost identical when comparing the McIntosh replacements lamps with the original bulbs.

In this picture you can see the 1866 replacement lamp installed in the left socket and the McIntosh labs replacement lamp installed in the right socket.

index.php


Everything is back together now and I’m happy to report that the lighting of my MC2105 is matching my C26 nicely now. Thank you to everyone for your input and advice.
 
Last edited:
Primarily the letter bulb (replacement for the 1866). However, I might also replace the meter lamps simply to avoid the hassle of wrestling with these heavy units just to replace another burned out Incandescent. I own two of these amps and find it necessary to do minor repairs on one of them at least once a year. So please provide data for both bulbs. Thank you.
 
You must log in or register to reply here.
Back
Top Bottom