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Re: Wiring a reverse phase jumper cable


 
12/9/2005 1:06 PM
anonymous Re: Wiring a reverse phase jumper cable
So basically, you maintain there's no way to do polarity reversal with say a hammond project box, some jacks, a DPDT toggle and two-signal shielded wire?  
 
I'm not accusing you of being wrong, but I received a suggestion from a well-known amp tech on how to make one. I'm going to keep his identity anonymous here because he said... "I asked you the time and you're telling me I need to build a watch," or something like that.  
 
So, if I understand his notes, it looks like I jumper the channels by connecting each channel to a jack on this project box. The incoming jack is wired to the DPDT. The signal is inverted at the DPDT and wired back to 2 output jacks via two-signal wire. Now I have two output jacks on the box - one standard polarity, the other inverted, selectable with a DPDT toggle. Sounds like a useful tool to me. Does this sound right?
 
12/9/2005 1:10 PM
starfish
So basically, you maintain there's no way to do polarity reversal with say a hammond project box, some jacks, a DPDT toggle and two-signal shielded wire?  
   
I'm not accusing you of being wrong, but I received a suggestion from a well-known amp tech on how to make one. I'm going to keep his identity anonymous here because he said... "I asked you the time and you're telling me I need to build a watch," or something like that.  
   
So, if I understand his notes, it looks like I jumper the channels by connecting each channel to a jack on this project box. The incoming jack is wired to the DPDT. The signal is inverted at the DPDT and wired back to 2 output jacks via two-signal wire. Now I have two output jacks on the box - one standard polarity, the other inverted, selectable with a DPDT toggle. Sounds like a useful tool to me. Does this sound right?
 
 
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12/9/2005 2:37 PM
Rick Erickson
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Try it and see. If he's a well known tech he must be right. ;)  
 
RE
 
11/23/2005 12:36 PM
regis
R.G. has a white paper on phase reversal on his webpage:  
 
http://www.geofex.com/Article_Folders/polarity_reverser/polarity_reverser.htm  
 
Seems like that should do the trick.
 
12/9/2005 1:09 PM
starfish
I could build one of these no problem, but adding components is what I'm trying to avoid. I want to keep the signal path as minimal as possible. See my other post re: advice from a well-known amp tech. He suggested a box with jacks, a DPDT toggle and 2-signal wire. What's your take on that?
 
12/9/2005 2:43 PM
Rick Erickson
email

It won't work because you have a common ground and when you reverse the phase of one jack you will be grounding the hot side of the signal to ground.  
 
RE  
 
P.S. - Rock stars know my name... now will you believe me?
 
12/9/2005 6:28 PM
starfish
>>>  
It won't work because you have a common ground and when you reverse the phase of one jack you will be grounding the hot side of the signal to ground.  
>>>  
 
How so? Using a 2-signal wire + shield. The sheild is not used for signal.
 
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