MC2100 Question

welcomdmat

welcomdmat

Super Member
I have asked a few questions about things that I would like to own, but I have just had one come up about something that I own.

I have been going through my standard record listening, and a track fuzzed out. Hmm -- right?

I assume that there is a big bit of crap on my stylus. I pick it up, clean it, and music plays again. For about 10 min.

Hmm -- again

I notice that the top of my MC2100 closer to -- I guess -- the back, is noticeably warmer than the front (back being plug ins, front being no plug ins). Very strange. Certainly not focused anywhere near the big caps. Focused over the heat sinks.

I am thinking to myself when -- !click! -- and the music comes back on. (the click was not loud. I don't know if I heard it or felt it with my hands)

I have not had any trouble over the next few minutes that it took me to type this, and I am powering down now.
 
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As I face the McIntosh 2100, and using the large caps as a center line, the left side is noticeably warm and the right side is room temperature


I am guessing the answer is that I have to go to my local repair guy, but I hope there could be something I am not thinking about.

My current local guy comes to my house, picks it up, takes it somewhere, works on it, and then brings it back. Sadly, I don't currently have that "friend" who is very knowledgable and will squeeze in some home audio pieces.
 
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It cooled down quickly -- fast may be a bit much -- and there is no smell like burning dust or anything.

The system is quite clean, so I don't know if there would be a smell of dust if there is no dust.
 
If you look at the amp with the transformers at the back (3 rectangular blocks) can caps towards you the right side of the cage contains the LH heat sink (away for the jacks and speaker connections).

Check your speaker wire for accidental shorting, might even try to swap L for R speaker connections to make sure it does not swap channels. RH physical side still gets hot.

Have your tech, if you bring it to him, confirm that the bias resistor has not drifted and is the correct value for the driver transistors. I have found too many have drifted so now I always replace them whenever a soldering iron is hot near by.

There is a heat sensor attached to one of the channels heatsinks that will open and shut off the AC power if it gets too hot......you must have very sensitive hands or ears to sense it's minute click.
 
c_dk said:
There is a heat sensor attached to one of the channels heatsinks that will open and shut off the AC power if it gets too hot......you must have very sensitive hands or ears to sense it's minute click.
Click to expand...

I cannot see all that well or hear all that well, but I do have great visual and aural reflexes.

I recently tried to run some 12 awg BlueJeans speaker wires. The amp side had their forks designed for McIntosh. I had the other side as bare wire. My speakers did not like the large cable, so I started over.

It seems I need to start from the beginning and re-work my speaker wire.

I was really disappointed that the BJ 12 awg wouldn't work with my speakers, but they are old, and I am not that beat up about it.
 
When I update Mac speakers I always replace the silly press connections with 5 way binding posts......back in the day we had what was called "flex pins" a crimp on connected flexible braid that would fit into those push button type speaker connectors. Check at parts express to see if they might have something similar.
 
I have barrier strip specific spades on one end of my new speaker wire, but my speakers will not take 12 awg wire into their binding posts. That forced me to re-introduce my 16 awg Monster wire. That wire was probably frayed -- or at least beat up a bit -- so I have disconnected everything with the plans of working a bit more tomorrow on clean wire.

The best course of action would be to have 5 way binding posts installed on my speakers. That may be a plan for the first part of next year.
 
Fast. Cheap, easy test in that vein.
With nothing connected to amp. Do you have the uneven heat issue.
This should rule out, speaker wire, speakers from the equation :idea:
 
Heating feels to be even, so something must have gone astray when hooking up the speakers.

I am going to un-do everything and do it again!


Thank you very much for the quick and helpful responses.
 
I cut a new pair of cables, prep'd them, and installed them. That seems to have fixed things.

Sadly, I cannot say what was wrong last time. Potentially a mistake in the markings on the speaker wire housing, but most likely it was user error.
 
McIntosh has always built in a number of " safety" devices and circuits into their amps to minimize the depth of problems which might happen.

A few stray strands of the speaker wire shorting to ground, a dead shorted out speaker driver, playing the system loud when no one else is around......

Reminds me of a story told to me by a long time client......he had grown his system throughout a few decades into his 3rd generation of seperates. His wife teased him about his hobby, allowed him to do it always making sure he knew it was his system, of no interest to her......except everyday when he came home from work the amp was always warm, off, but definitely warm. He knew she was telling him a little lie, she had been playing, cranking?, the system all day long!
 
I work from home, so there is always time for tinkering. I was disappointed when my new speaker wire (12 awg) did not work with my older speakers. I put the old wire back and didn't think much of it.

I should have taken a deep breath, set aside an appropriate amount of time, and installed new speaker wire of appropriate gauge.

There is no doubt that the craftsman is at fault here.

I will still ask my wife about her listening volumes.
 
There is always a second part of the story.....good natured bantering between a couple married for over 30 will always have a second part.....

One of his upgrades was selling off his vintage ML2 loudspeakers to his nephew. The ML2s which measure approx. 30X20x30 inches WxDxH, he replaced them with a pair of 12X14X44 inch towers. He then discovered he needed to buy two glass enclosed display cases for her figurine collection since she no longer had the speaker tops to display them on......the display cases cost almost as much as the speaker upgrade cost.......

True story......he got a arm punch while he was telling me this tale with her standing there of coarse.
 
Sorry Folks. I have been behind in my posting. The MC-2100, depending on which production run yours is, have an updating to the driver circuits for both channels. This update compensates for the aging of the original components with newer, more reliable devices. If the unit has not been updated this could be an indication that it should be accomplished. Mark - McIntosh Service Center.
 
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