tofu Posted July 18, 2005 Share Posted July 18, 2005 i unplugged my mcintosh mc250 and said to myself "hmm, this plug doesnt have one fatter 'connector,' so how am i supposed to know which way is right side up?" well, i plugged the sucker in upside down and i could swear a hear a difference. placebo is lingering in the back of my head. someone tell me if what i'm hearing is real. i would assume plugging it in upside down would put everything in a sort of.. reversed phase (not sure if this is the correct terminology, don't laugh ), but then again i do remember reading that we can't tell the difference which way the phase is, as long as everything else is the same. enlighten me. thanks. Quote Link to comment Share on other sites More sharing options...
Duke Spinner Posted July 18, 2005 Share Posted July 18, 2005 see which wire, either visually, or with an ohm meter .. is bonded to the chassis .. that is the neutral and should go to the "fat" slot in the wall plug Quote Link to comment Share on other sites More sharing options...
tofu Posted July 18, 2005 Author Share Posted July 18, 2005 ah, all right. thank you both. Quote Link to comment Share on other sites More sharing options...
D-MAN Posted July 18, 2005 Share Posted July 18, 2005 Since AC is converted to DC in the PS of the amp, it doesn't matter. If any AC gets through to the output, you hear it as 60 cycle hum. I rest my case. DM Quote Link to comment Share on other sites More sharing options...
scotbuck Posted July 18, 2005 Share Posted July 18, 2005 Greetings, I've had several experience where changing the polarity of the AC plug causes a substantial difference. On some of my guitar amps, and most recently my turntable, there is definitely a "right" and "wrong" way to plug the two-prong plug in. The "right" way generates less noise. Also, in live music, if you find that your guitar amp has a different polarity from the PA system and you happen to touch your microphone, you'll be in for a real shock! I believe that's why many vintage amps (with a two-prong AC cord) have a polarity switch which lets you find the "right" setting without having to unplug the amp. Hope this helps... Take care, Scott Quote Link to comment Share on other sites More sharing options...
3dzapper Posted July 18, 2005 Share Posted July 18, 2005 "I've had several experience where changing the polarity of the AC plug causes a substantial difference." My experirnce with a Scott 299C was similiar to Scotbuck's. There was a substantial difference in PS noise with plug reversal. I marked the plug with a Sharpie so I can always put it in correctly now. Rick Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted July 18, 2005 Share Posted July 18, 2005 ---------------- On 7/18/2005 5:26:21 PM 3dzapper wrote: "I've had several experience where changing the polarity of the AC plug causes a substantial difference." My experirnce with a Scott 299C was similiar to Scotbuck's. There was a substantial difference in PS noise with plug reversal. I marked the plug with a Sharpie so I can always put it in correctly now. Rick ---------------- I've had the same experience with an HF-81. Surprising enough of a difference for me to mark the plug for correct polarity. Quote Link to comment Share on other sites More sharing options...
tofu Posted July 18, 2005 Author Share Posted July 18, 2005 hmm... so perhaps it WASN'T just placebo. Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted July 18, 2005 Share Posted July 18, 2005 Yeh, I sure don't comprehend the technical issues, or why it isn't an issue in every case. However, I do know what I hear with my ears. I don't think it's the placebo effect. I can understand how that works when someone spends big bucks on interconnects or something, it better sound better. This is something else. Quote Link to comment Share on other sites More sharing options...
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