I own a pair of
McIntosh MC611 monobloc amplifiers that I purchased new over a year ago.
Since that time
I have sensed that something was wrong and I have been continually trying to
track-down an imbalance in my system. I wasted many hours, labour and
equipment-switching to diagnose the problem.
with the help of the dealer and a technician did I find out what the problem
was. In fact it is two problems:
There was a
mistake made at the factory, in which plugs from the input board (J8 & J9) were reversed,
resulting in one channel being out-of-phase! (improper imaging/no centre image)
Single-ended/Balanced switch on the back panel does not function properly.
Corrosion from the circuit board coating chemical on that switch causes
intermittent problems with the signal and a lack of proper power output of the
amp, resulting in a volume imbalance. (which also ruins imaging)
I wasted a lot
of time and trouble getting this problem diagnosed, but the McIntosh factory is
not interested in making this in a general recall.
So, let's call
this a 'Public Service Announcement'. I would not wish for anyone else to go
through this trouble, expense and aggravation. I have been told that there is a
(secret) Service Advisory regarding this problem, so there must be more of you
out there with the same trouble.
will not see any information about it on the McIntosh website! Let it also be
known that it will not get detected on a test bench. See test meter readout. Also
switching polarity at the speaker will bring out the problem but will also
introduce harmonics – due to the nature of the circuitry.
If there are
more of you out there, be advised….and I think we should be entitled to some
compensation from the manufacturer.
http://https//drive.google.com/file/d/1LltpAgRtvbs3ednoBBQ02YOKhUXVznSL/view?usp=sharing http://https//drive.google.com/file/d/1Wq_1STg3bc-Gl5IhXAdpyq59uW3Ln1A6/view?usp=sharing http://https//drive.google.com/file/d/1wlxAZ6WimNBUz7qzt2nN-ftRcyWfLAkm/view?usp=sharing http://https//drive.google.com/file/d/1f69QE9J9xKcWKUwj76d6oxjdf1w06jBG/view?usp=sharing http://https//drive.google.com/file/d/14vRZyMV6_ZwAqwMCMXr3W6HqnIv6Tsm8/view?usp=sharing