2. amps-preamps
  3. 153500-63554

Polarity Conundrum

I recently bought an Audio Research LS-15 preamp and an Accuphase P-450 power amp from other Audiogoners. They will be connected via the balanced XLR ins/outs, but the polarity scheme is the opposite in each piece. The LS-15 is Ground/Positive/Negative, the P-450 is Ground/Negative Positive. Someone(s) on another thread suggested that the simple way to address this polarity inversion is by swapping the speaker leads to the amp to the opposite connectors.
Instead of positive to positive, you go positive to negative/negative to positive on the amp's output terminals. Can it be that simple? The Audio Research manual says to contact them when this situation is encountered, but if this simple fix will work, I'm all for it. What say you guys?
discnik
delkal
110 posts
 
Its reasonable to think you want your system to play with the correct polarity but not all recording are mixed with the correct polarity.  So it is hard to know what you are listening too.  According to this site 92% of CDs are inverted polarity.  I guess you can look at their list and swap your speaker cables for the various albums before you play it.    Or you can not worry about it and enjoy the music.

http://audiogeorge.com/the-polarity-list/  
discnik OP
144 posts
 
Thanks for the responses....the one source that I'll also have connected via XLRs has the US-version polarity arrangement, so that helps rather than hurts the situation. My speakers are passive and I am using a sub, but it is connected directly to preamp outputs on the LS-15. My head tells me to reverse polarity at the amp outputs, but my gut says to wire as normal and see how that sounds first. It doesn't help that I haven't had the speakers I'm using (Vandersteen 3As) very long, so discerning any subtle differences, if any, may be difficult.
imhififan's avatar
imhififan
2,101 posts
 
More options:

https://www.amazon.com/dp/B0002J1JN6/ref=psdc_11973421_t2_B000068O4L

https://www.amazon.com/Hosa-GXX-195-XLR3F-XLR3M-Reverser/dp/B000068O4L
geoffkait's avatar
geoffkait
23,365 posts
 
I don’t think anyone really knows the actual percentage of CDs that are manufactured or recorded in correct polarity. I’m not sure I even follow the logic for how George Louis arrives at 92%. If it doesn’t make sense it’s not true. Besides, some of the CDs George Louis claims are in reverse polarity in reality sound like they are in correct polarity. There may be many others. 

The obvious best solution is a polarity switch on the preamp. Otherwise one would have to listen to each CD and mark it for polarity. The system polarity can be checked using the XLO Test CD or any Test CD with a track for testing whether the system is in phase or out of phase. But that actually doesn’t help too much since there are presumably a lot of CDs that are in reverse polarity. Nobody knows how many.
More to discover