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Understanding Mcintosh Meters?

This is probably a stupid question, or atleast one I should be able to answer myself, being that I did graduate with a degree in computer engineering, but I recently got a mcintosh ma6450, and was wondering how I make sense of the meters. I understand what they measure, and what it means, but how do i know when I am close to clipping.

Let me explain further. the amp is rated 100wpc, in to 4 ohms and the meters read from .01 to 100 watts with the final mark being 200 watts. But what if my speakers are 8ohms? I know that means my amp produces about 50 watts in to 8ohms, but does that mean that I can only take the meters about 1/2 way before I will clip, or do I go by the decibels, meaning 0db is really the max before clipping, only instead of producing 100wpc (0db corresponds to 100w watts on the meters), the amp is only producing ~50wpc since the speakers are 8ohms.

Hope I explained my question well enough. Thanks for your help.

farjamed
farjamed OP
33 posts
 
Ok, so i thought I understood the meters. But apparently they arent as useful as I thought. They arent really measuring anything. They pretty much are just there for looks. Let me explain.

Someone said, the meters could help tell whether your system was hooked up properly, but as long as there is a source being fed into them, they will react to the music regardless of whether or not speakers are even connected.

My left meter has been reading sligtly less than my right meter. I thought maybe when i moved the amp around recently the left speaker wire came a bit loose from the connection. Upon inspection I realized they have nothing to do with speakers being connected or not.

I am confused now.
musicnoise
377 posts
 
If you want to see what the meters are measuring and at what point, the schematics for all of the currently sold amplifiers are available from Mcintosh for a very nominal feel. Suggest buying the schematics and studying them - which will dispel the idea that the meters measure nothing.
bjesien
1,337 posts
 
I had the MA 6450 and the meters come in handy to the extant that you know when you are coming close to overdriving the amp. As far as reading them, the 6450 has an 8 ohm and 4 ohm overlay. You read the top or bottom, depending on the impedance of your speakers. It's close enough to tell what is going on. Plus the powerguard is nice. You should see the red lights flash if it's protecting it from clipping.
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