AK member dgwojo likely has them in a long-life version that will save you doing again in a couple of years. Change them all, not just the two that are burned out.
McIntosh - Hints and Kinks
- Thread starter dewickt
- Start date
- Status
s-petersen
Scott
Differences in c20's
Hi Terry,I have a c20 that I'm trying to resurect,it was built in a console,so that the original faceplate was missing,I bought a bunch of parts,but they are for the shorter height 4 1/2 " pin spacing on the end caps.The preamp I have was set up for 4 3/4 spacing,Do you know if I just need different side mounting plates,or is the chassis different?
I also posted on this thread
http://www.audiokarma.org/forums/showthread.php?p=5303731#post5303731
Thanks
Hi Terry,I have a c20 that I'm trying to resurect,it was built in a console,so that the original faceplate was missing,I bought a bunch of parts,but they are for the shorter height 4 1/2 " pin spacing on the end caps.The preamp I have was set up for 4 3/4 spacing,Do you know if I just need different side mounting plates,or is the chassis different?
I also posted on this thread
http://www.audiokarma.org/forums/showthread.php?p=5303731#post5303731
Thanks
s-petersen
Scott
Hi Terry,
The glass and volume plate actually line up with the control spacing,it seems centered but I will have to use some washers/spacers from the top and bottom covers,and different side plates,I'll have to make the narrow end caps,and flag pointers as they can't be had.
Thanks.
The glass and volume plate actually line up with the control spacing,it seems centered but I will have to use some washers/spacers from the top and bottom covers,and different side plates,I'll have to make the narrow end caps,and flag pointers as they can't be had.
Thanks.
Mac1500
Hi Terry,
I'm working on a late production MAC1500 and had a question about the seven 5 watt power resistors used in the power supply section. Out of the 7 main resistors, two are 5 watt carbon and the rest are 5 watt wirewound. It looks like one carbon supplies the plate voltage for the 12AX7, and the other supplies voltage in the solid-state preamp. Any particular reason McIntosh would have used carbon instead of wirewound? The 2 carbons (12K ?...best guess from looking at the darkened color bands, but could be wrong) have gotten hot and changed values, which seems to be a common problem from looking at pictures of other later serial numbered 1500's. What type of resistor should be used to replace them, since carbons in 5 watts don't seem to be available anymore.
Any help would be appreciated, thanks!
Hi Terry,
I'm working on a late production MAC1500 and had a question about the seven 5 watt power resistors used in the power supply section. Out of the 7 main resistors, two are 5 watt carbon and the rest are 5 watt wirewound. It looks like one carbon supplies the plate voltage for the 12AX7, and the other supplies voltage in the solid-state preamp. Any particular reason McIntosh would have used carbon instead of wirewound? The 2 carbons (12K ?...best guess from looking at the darkened color bands, but could be wrong) have gotten hot and changed values, which seems to be a common problem from looking at pictures of other later serial numbered 1500's. What type of resistor should be used to replace them, since carbons in 5 watts don't seem to be available anymore.
Any help would be appreciated, thanks!
dewickt
Will fix about Anything
The large carbon comps are 2W, when made they were all that was needed, to bad they had a tendency to cook with aging, go up in value slightly when hot, then try to self destruct. Replace, if needed, with 3W wire wound or 5W sand block, either will work OK if rated as non-inductive.
Wow. This is harder than I thought, trying to find some 12K ohm NON-INDUCTIVE wirewound resistors. Tried Mouser and a bunch of others. What am I missing? Terry? Anyone?
Thanks.
Brentleew
New Member
Mcintosh Resistance values
I have an MC-250 that I am repairing because an output transistor blew. And as a result two resistors went as well. The problem is that the service manual specs say 120 ohms, 1/2 watt, 5 %. While the installed values ( both right and left power output PCB 043-916 ) are 150 ohm, 1/2 watt, 5 %. This is R-52 right channel. It was burned so I looked at the other board. I don't believe they have ever been modified or worked on. Also, no other components appear to be different. Why would they install 150 ohm resistors? Slight design change?
I have an MC-250 that I am repairing because an output transistor blew. And as a result two resistors went as well. The problem is that the service manual specs say 120 ohms, 1/2 watt, 5 %. While the installed values ( both right and left power output PCB 043-916 ) are 150 ohm, 1/2 watt, 5 %. This is R-52 right channel. It was burned so I looked at the other board. I don't believe they have ever been modified or worked on. Also, no other components appear to be different. Why would they install 150 ohm resistors? Slight design change?
HELP: Need HOW TO install MC2105 Glass replacement
gentlemen, terry,
I am getting a replacement glass delivered...the MC2105 fell and hit my foot; I let it smash the ashfault...only the glass broken down a caty corner...and my foot survived...oddly I loaned it to a friend to tire kick and I felt it front heavy too late when he handed it to me...stupid $120 mistake.
So can anyone tell me the short steps to replace the glass? I ordered from MC and they said it's like a picture frame...I assume remove the screws on the chrome ends right, then all knobs and I assume the glass it right there, just slide out the old cracked one and place the new on; knobs first then the ends? How tight should the screws be on the ends? Is that all there is too it?
Thanks for guidance for an old guy.
Cheers.
Thank goodness the cabinet was on - the ashfault was warm so that was good also..it appears the friend did not tell me he dusted and waxed the cabinet...hence the slippage.
Expensive lesson.
Regards John
gentlemen, terry,
I am getting a replacement glass delivered...the MC2105 fell and hit my foot; I let it smash the ashfault...only the glass broken down a caty corner...and my foot survived...oddly I loaned it to a friend to tire kick and I felt it front heavy too late when he handed it to me...stupid $120 mistake.
So can anyone tell me the short steps to replace the glass? I ordered from MC and they said it's like a picture frame...I assume remove the screws on the chrome ends right, then all knobs and I assume the glass it right there, just slide out the old cracked one and place the new on; knobs first then the ends? How tight should the screws be on the ends? Is that all there is too it?
Thanks for guidance for an old guy.
Cheers.
Thank goodness the cabinet was on - the ashfault was warm so that was good also..it appears the friend did not tell me he dusted and waxed the cabinet...hence the slippage.
Expensive lesson.
Regards John
There are a few (3?) along the top and bottom as well as a couple on each side. The the 'frame' pieces pull out to the front. put the new glass in the 'frame' pieces and reverse the process. And, it is 'asphalt' you dropped it on.
Foam and plexi on replacement glass mc factory mc2105
My apologies for the spelling. I removed the broken glass awaiting the factory. Am i to assume the replacememt glass is turnkey with plexi shell already mounted on the back and new foam around the meter top as the old glasss did?
The old foam turned to dust or do i need to cut and make new foam?
Thanks
My apologies for the spelling. I removed the broken glass awaiting the factory. Am i to assume the replacememt glass is turnkey with plexi shell already mounted on the back and new foam around the meter top as the old glasss did?
The old foam turned to dust or do i need to cut and make new foam?
Thanks
I've not gotten new glass from the factory, so cannot answer your new questions. Am guessing you will need to install all new pieces of foam, as mine came to me "naked" (no foam, blue gel, or anything other than the piece of glass), though through a dealer.
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FINAL: How to instll MC2105 Glass and Versions
Dear Readers and Experts, Enthusiasts alike,
Or in my case learning.
Received 2 glass, one from Factory and one from Audio Classics.
Both teams worked admirably to answer my ?'s and give guidance...Both were received in near flawless condition but the bubbling on the headphone jack appears to be the way the glue is applied on the back of the grommet...both plates of glass showed some residue and unevenness...AC was $150 + $18 S/H came in a wood frame, MC Fact $117+ S/H of $12 bubble-wrap and well done.
Take apart frame 1 hour to get it right...put it back together about 30 minutes. The struggle is the bottom rail, suggest bottom rail first and build frame - new foam was applied at the factory but oddly there was no room for any foam on the top and bottom rail due to the new foam on the vertical sides and around meter. One must transfer the clear plexiglass diffuser as well old glass to new.
I struggled with the frame and getting it into position. The end caps are not to be put on until the entire frame is applied per Mc - too much tension on the glass...once I got the bottom rail in tight it was simple - put all the 10 screws back in and power it up.
I cleaned the green lens which on this is affixed to the front of the chassis by 2 screws which I lightly de-tensioned due to some bowing and meter crush on the arms...very delicate...I adjusted for ZERO mark.
The green is actually much nicer than before due to no foam residue floating around.
interestingly, the glass has these special dots of metal foil to keep the bulbs from heating the glass on the back side...
Well that was the exercise and now I have a spare glass as well.
My rationale for using both parties was to see the diff. in glass and compete...I could have save some money by 1 glass and Factory only I guess...but it's done.
Cheers. and thanks to all those who went before me and who helped me via emails.
Dear Readers and Experts, Enthusiasts alike,
Or in my case learning.
Received 2 glass, one from Factory and one from Audio Classics.
Both teams worked admirably to answer my ?'s and give guidance...Both were received in near flawless condition but the bubbling on the headphone jack appears to be the way the glue is applied on the back of the grommet...both plates of glass showed some residue and unevenness...AC was $150 + $18 S/H came in a wood frame, MC Fact $117+ S/H of $12 bubble-wrap and well done.
Take apart frame 1 hour to get it right...put it back together about 30 minutes. The struggle is the bottom rail, suggest bottom rail first and build frame - new foam was applied at the factory but oddly there was no room for any foam on the top and bottom rail due to the new foam on the vertical sides and around meter. One must transfer the clear plexiglass diffuser as well old glass to new.
I struggled with the frame and getting it into position. The end caps are not to be put on until the entire frame is applied per Mc - too much tension on the glass...once I got the bottom rail in tight it was simple - put all the 10 screws back in and power it up.
I cleaned the green lens which on this is affixed to the front of the chassis by 2 screws which I lightly de-tensioned due to some bowing and meter crush on the arms...very delicate...I adjusted for ZERO mark.
The green is actually much nicer than before due to no foam residue floating around.
interestingly, the glass has these special dots of metal foil to keep the bulbs from heating the glass on the back side...
Well that was the exercise and now I have a spare glass as well.
My rationale for using both parties was to see the diff. in glass and compete...I could have save some money by 1 glass and Factory only I guess...but it's done.
Cheers. and thanks to all those who went before me and who helped me via emails.
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