Jump to content
The Klipsch Audio Community
Sign in to follow this  
Toxicant

McIntosh Amp Hum??

Recommended Posts

Hello all,

I have a Mac 2120 ss amp and it has developed a hum in one of the channels. I tried switching all the wires from left to right on the pre-amp and then discovered that even with the volume turned off on the pre, if I turn up the amp output control the hum is there. This is how I determined it has to be the amp, correct me if I'm wrong.

Anyone know what would cause this and if its possible to fix this myself or could recomend some place to send it. I've had the amp for 20 years and have never had anything done to it, any idea what something like this would cost to fix? I paid less then $200.00 bucks for the amp will it be possible its not worth fixing?

thanks,

Share this post


Link to post
Share on other sites

Have you checked out the McIntosh web site?

You can find service centers to call. You can even ship it back to McIntosh, they repair and re build every amp that they ever made.

Price? I have no idea and they might not eather without seeing it. Then you must ask yourself how much you like the amp and how much it will cost to replace it.

McIntosh equipment is kind of like the Klipsch Heritage line, by the way they hold their value.

Share this post


Link to post
Share on other sites

Typically AC-level hum (60 cycle) suddenly popping up on one channel would indicate that a power-supply cap is going (or has gone) south. Probably. If it was both channels doing the humming, I would suspect a grounding problem first. But one channel only is usually power-supply.

No easy fix there. Sorry dude.

DM8.gif

Share this post


Link to post
Share on other sites

Tox

Look around for a good McIntosh guy in your area. Every big city has one or two. I know of a guy here in Milwaukee WI who fixes mine when needed. I recently got an excelent ebay deal on a "broken" 250, my guy fixed it for $80, I am very a head of the game on that deal.

If it were me I would fix it any Mcintosh amp.

If you don't want to fix it, Let me know, I will take it off your hands, fix it and use it.

JM

Share this post


Link to post
Share on other sites

"Typically AC-level hum (60 cycle) suddenly popping up on one channel would indicate that a power-supply cap is going (or has gone) south. Probably. If it was both channels doing the humming, I would suspect a grounding problem first. But one channel only is usually power-supply."

Inverted logic. Wrong conclusion.

"Hello all,

I have a Mac 2120 ss amp and it has developed a hum in one of the channels. I tried switching all the wires from left to right on the pre-amp and then discovered that even with the volume turned off on the pre, if I turn up the amp output control the hum is there. This is how I determined it has to be the amp, correct me if I'm wrong."

Inverted logic. Wrong conclusion.

I'll give you a clue:

"if I turn up the amp output control the hum is there."

So that means if the amp controls are down there is no hum.

Un-hook the preamp and cables, turn on the amp and run up the volume control. From what you've said it will still be quiet.

If you would bother to look at the diagram on the top of your preamp you would see the signal goes (simplified):

input jack

selector switch

volume control

line/tone amp

output jack

Power amp goes:

input jack

impedance buffer

volume control

amp

output jack

If the amp makes hum without the preamp, one of the impedance buffers is bad. If the amp is quiet without the preamp then one line/tone amp is bad.

"Anyone know what would cause this and if its possible to fix this myself or could recomend some place to send it. I've had the amp for 20 years and have never had anything done to it, any idea what something like this would cost to fix? I paid less then $200.00 bucks for the amp will it be possible its not worth fixing? "

How high is up?

If you're worried about cost, you can't afford it.

Share this post


Link to post
Share on other sites

hey, djk!

You could be right, I didn't read it fully; if the power supply is "bad" then the amp would (or could) hum REGARDLESS of the volume setting. So I stand corrected.

Toxicant: good luck, may be an easy fix after all!

DM6.gif

Share this post


Link to post
Share on other sites

Thank you for your replys, I'll have to check this out futher when I get home.

"If you're worried about cost, you can't afford it."

People that don't worry about cost either didn't earn their money or are stupid.

Good Day,

Share this post


Link to post
Share on other sites

"People that don't worry about cost either didn't earn their money or are stupid."

Sorry you have cerebral rectitus and can't figure out something this simple.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...