Repairing an old McIntosh : Part II

namui · 3rd January 2001, 03:21 AM

Thanks for a few replies on my last question. Since the last problem is occasional and therefore difficult to really locate, and I've tested a few things as suggested, I've decided to replace the filter caps and if the problem still remains, I'll replace the output transistors.
There is another problem, though. Once turned on, there is a tik-tik-tik.... sound coming out of the tweeter of both channel, loud enough to barely hear from about 2 feet away. This also causes the VU-meter (almost all solid-state Mc's have this meter) to continuously bounce slightly. Its sound is similar to alternately tapping the nails of our two fingers on the desk as fast as we can.
I've tried paralleling each filter diode with a small cap, but it didn't work. Any suggestion ?

robertpear · 5th January 2001, 12:29 AM

Replace the fliter caps in the low voltage section to. Your low level tic is proably a slow oscilation cause by the power supply having poor output impeadance caused usally by the filter caps being open or leaky.

djk · 5th February 2001, 12:16 PM

The sound fading out and the power guard light turning red is probably the cap in the feedback loop to ground going open.I own two MC2120.The same as yours less the meters.

5th January 2001, 12:29 AM	#2
robertpear diyAudio Member Join Date: Jan 2001 Location: Lawrence, Kansas	Replace the fliter caps in the low voltage section to. Your low level tic is proably a slow oscilation cause by the power supply having poor output impeadance caused usally by the filter caps being open or leaky. __________________ Bob P

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
what part can take the place of ST part VB408B completely	peterchen88	Parts	0	8th September 2007 05:45 AM
part# for spare part for CDM-1 wanted	joe	Digital Source	5	20th March 2007 07:59 AM
Repairing an old McIntosh	namui	Solid State	3	4th May 2005 12:35 PM
Repairing Mcintosh MC2300	diyman	Solid State	0	12th August 2004 11:13 AM
Mcintosh C26	bonsai171	Solid State	2	8th May 2004 02:58 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

3rd January 2001, 03:21 AM	#1
namui diyAudio Member Join Date: Nov 2000	Thanks for a few replies on my last question. Since the last problem is occasional and therefore difficult to really locate, and I've tested a few things as suggested, I've decided to replace the filter caps and if the problem still remains, I'll replace the output transistors. There is another problem, though. Once turned on, there is a tik-tik-tik.... sound coming out of the tweeter of both channel, loud enough to barely hear from about 2 feet away. This also causes the VU-meter (almost all solid-state Mc's have this meter) to continuously bounce slightly. Its sound is similar to alternately tapping the nails of our two fingers on the desk as fast as we can. I've tried paralleling each filter diode with a small cap, but it didn't work. Any suggestion ?

5th February 2001, 12:16 PM	#3
djk diyAudio Member Join Date: Feb 2001 Location: USA	The sound fading out and the power guard light turning red is probably the cap in the feedback loop to ground going open.I own two MC2120.The same as yours less the meters.