McIntosh MA6100 restoration

[Phil Nelson]

I picked up a McIntosh MA6100 integrated amp last week and its volume control is very scratchy. I found some old threads in this forum that said it's tricky, but not impossible, to clean the controls and switches with DeOxit and Faderlube, so I started disassembling. I have gotten off the knobs and dial glass, and gotten to the point where I can slightly lift up the board holding the top row of controls.

I read an old thread in this forum stating that Faderlube (not DeOxit) must be used on these controls. Is my can of CaiLube acceptable?

Along the way, I found that the socket for one of the pilot lamps has been pushed back into its recess behind the frame.

It looks tricky to get that socket back into place, much less access the pushbutton switches for cleaning. Any hints for accessing stuff on that lower panel?

In case you haven't guessed, I'm not a professional tech. I have restored tube radios and TVs, but have little experience with solid state gear.

Thanks!

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

 

[AbSoundLabsMN]

I picked up a McIntosh MA6100 integrated amp last week and its volume control is very scratchy. I found some old threads in this forum that said it's tricky, but not impossible, to clean the controls and switches with DeOxit and Faderlube, so I started disassembling. I have gotten off the knobs and dial glass, and gotten to the point where I can slightly lift up the board holding the top row of controls.

I read an old thread in this forum stating that Faderlube (not DeOxit) must be used on these controls. Is my can of CaiLube acceptable?

Along the way, I found that the socket for one of the pilot lamps has been pushed back into its recess behind the frame.

It looks tricky to get that socket back into place, much less access the pushbutton switches for cleaning. Any hints for accessing stuff on that lower panel?

In case you haven't guessed, I'm not a professional tech. I have restored tube radios and TVs, but have little experience with solid state gear.

Thanks!

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

 

[AbSoundLabsMN]

Clailube isn't for cleaning controls. You should use DeOxit F5, which is for cleaning non-metal to metal sliding contacts. We have used Calilube on some seriously compromised controls, with sporadic success.

DeOxit D5 is for cleaning metal to metal contacts.

Mark
McIntosh Service Center
(952) 894-5580

 

[c_dk]

Google search caig and calilube and you will see that Caig Industries changed the name calilube to faderlube in 2006.

Caig even says they still have the same part# . My can of F5 is F5S-H6

DOB used to carry around 2 cans, a red one and blue one that he introduced to us in 1979 when I had my first chance to host a amp clinic with him. Much more expensive than the typical cleaners available from the local parts supplier but DOB insisted they were the only thing to use......so we did.

 

[Phil Nelson]

Thanks, I did end up using DeOxit on the controls & switches, as well as the board edge contacts. Now my MA6100 sounds great!

I eventually discovered that there are little holes in the PC board above the top row of controls, allowing you to slip the spray straw through the board.

I was able to winkle that lamp socket back into place after some fiddling. The foam strips around the switches were crumbling into dust, so I removed them and replaced them with felt strips. The voltages look normal, so I'm going to play the amp for a while rather than do a wholesale replacement of electrolytics.

Regards,

Phil

 

[AbSoundLabsMN]

Thanks, as I did forget to mention that Calilube was no longer sold, from about a decade ago. It became Faderlube (F5), which is now still sold. Dave O'Brian was absolutely correct with his use of Caig products and his having them at his disposal whenever he held a McIntosh Clinic. Dave's passing was a real loss to us all and he will always be remembered.

Mark
McIntosh Service Center
(952) 894-5580

 

[c_dk]

The last few times I had dinner with him he was under so much pressure I think he was happy to wrap up the program except for a few of us......