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McIntosh (MC601) amplifier overheating problem

Hello everyone - A buddy of mine has MC601s that have recently started overheating.  Each amp went into protection mode after emitting a burning smell, and both had to have an output transistor replaced (at different times).  

My internet digging has revealed that ThermalTrak transistors are not very reliable, or at least the early batches were not.  Ayre has also reported overheated MX-R amps with the same problem.  They apparently can fail after years of use, which is not good news for owners!

I'm trying to get a feel for how widespread this problem may be (at this point in time)?  Each transistor replacement is $400, and there's an awful lot of output transistors in MC601s...!!  I convinced my brother to also get MC601s so I'm starting to get really worried his will fail too in the near future.

So far, McIntosh's response to my inquiry has been vague and reticent, unlike Ayre who apparently went to great lengths to remedy this issue for their owners.  Has anyone out there had this problem with McIntosh or Ayre?  

aball
aball OP
2,018 posts
 
Hi g_nakamoto,  it's normal that both are overheating because they both have bad transistors in them.  The ThermalTrak transistors are the problem (which were made by On Semi, not McIntosh).  Going by the amp serial numbers, there appears to be hundreds of amplifiers with bad transistors in them, so we won't be the only ones with this problem.  We just happen to have experienced it, and, said something here about it.  Unfortunately, only a tiny percentage of McIntosh owners are active in the forums.

While I'm at it, a quick update:  McIntosh told me they would have the built heatsink/transistor assemblies made for us in 25-40 days.  It has now been 40 days and I haven't heard anything, so I sent them an email just now asking for an update.  Fingers crossed they at least come through with this.  Stay tuned.
yuchuinlu
7 posts
 
I was thinking about buying 601 used in the near future. Looks like I need to by 611 instead? Better to save more money now!
garebear
1,164 posts
 
…….I just read this thread as I found it very interesting and informative and I have spoken with Mac dealers and there is pervasive air of arrogance about Mac products. Rightfully so but to a degree that if I were given a glass of Kool Aid I just may pass on it. I am looking at the new 462. Aball ncie to see you again and my only suggestion would be to try and get ; Clearthink to use punctuation…..wow, those sentences were a paragraph long !!!!
chazzzy007
540 posts
 
A friend of mine has the exact same problem with his Mac stereo amp. 
aball OP
2,018 posts
 
Hi garebear, nice to hear from you!

Hi chazzzy, ok well wish him good luck. It has now been 55 days and still no parts, and no emails in the last 2 weeks. To add insult to injury, I got an automatic reply from the Customer Service Manager just now saying that he’s out of the office until 8/10. Well, today is 8/22.... Unfortunately, I think that says it all.
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