XLR Interconnect connected out of phase but sounding fine?

egg1dog

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Hi all,

I am currently selling some kit for a friend but I am seriously thinking of keeping the Graaf GM50B Integrated for myself as it sounds utterly amazing - to be honest I've never heard dynamics or transparency like it in my lounge!!

Now on just checking over the amp and connections last night I spotted a picture of the xlr input wiring on the back of the amp(see pic) I only have my cd player connected via balanced interconnects.

Pin 3 is positive, this is normally negative with pin 2 normally being positive?

So I should be getting a specially made xlr interconnect with the positive and negative pins reversed at the amp end but am reluctant to change anything due to the sound I am currently hearing. I've read if connected out of phase there will be no bass but I have more bass than I have ever heard on my Usher speakers?

Has anyone else ever had this predicament?

Thanks, Paul.
 

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Warszawa

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I'm not sure of the technicalities but It's not the same as with speaker cables and will do no harm. Most modern kit has pin 2 as hot. Took me years to notice my phono stage had the phase inverted with my Luxman amp. When I flicked the switch on the back of the amp to change it to pin 2 I didn't notice any difference.
 
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MGTOW

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Historically the convention was different on each side of the Atlantic, Pin 2 was 'Hot' in Europe, Pin 3 'Hot in the USA. In more recent times the Pin 2 'Hot' became the standard though anomalies do occasionally crop up.

Most amplifiers are not fully balanced, pretty rare in fact, even those with XLR inputs. The first thing such an amplifier does is to sum the 'hot' and 'cold' signals, (reversing phase on one 'leg') which then allows the signal to be amplified in the usual way, ie like any regular unbalanced input.

The only issue here is absolute phase, think of a recording that starts with a single bass drum beat. In a regular drum kit the 'skin' will move forward towards the listener first, a compression, if the system reverses phase, the 'skin' moves away, a rarefaction. This is absolute phase, whether it is audible or not is subject to some debate, often heated.
 

Warszawa

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whether it is audible or not is subject to some debate, often heated.
C7F.gif
 
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MGTOW

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A long time ago, I had reason to do some work with EMI Technical department, out at Hayes in west London.

One of their more mundane jobs was checking the phase of microphones that EMI had bought for their studios. European models were usually Pin 2 hot, US models Pin 3 so the US mics were rewired.

The EMI chap I was working with reckoned that about 1 in 10 of all mics tested were wired incorrectly, ie they did not conform to there own spec.
 

egg1dog

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I'm not sure of the technicalities but It's not the same as with speaker cables and will do no harm. Most modern kit has pin 2 as hot. Took me years to notice my phono stage had the phase inverted with my Luxman amp. When I flicked the switch on the back of the amp to change it to pin 2 I didn't notice any difference.
Thank you for your comment it sounds amazing as it is so I will carry on knowing I will do no harm, much appreciated.
 

egg1dog

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Historically the convention was different on each side of the Atlantic, Pin 2 was 'Hot' in Europe, Pin 3 'Hot in the USA. In more recent times the Pin 2 'Hot' became the standard though anomalies do occasionally crop up.

Most amplifiers are not fully balanced, pretty rare in fact, even those with XLR inputs. The first thing such an amplifier does is to sum the 'hot' and 'cold' signals, (reversing phase on one 'leg') which then allows the signal to be amplified in the usual way, ie like any regular unbalanced input.

The only issue here is absolute phase, think of a recording that starts with a single bass drum beat. In a regular drum kit the 'skin' will move forward towards the listener first, a compression, if the system reverses phase, the 'skin' moves away, a rarefaction. This is absolute phase, whether it is audible or not is subject to some debate, often heated.
thank you that makes total sense if this was the case with my Graaf not being fully balanced then I wouldn't notice if they were out of phase (and I don't) so that is good to know.

Thanks again.
 

HansBertil

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[…] I've read if connected out of phase there will be no bass but I have more bass than I have ever heard on my Usher speakers? […]
Yes and no. If you connect one channel out of phase with the other you will lose bass due to cancellation between the woofers. If you on the other hand connect both channels out of phase there will be no loss at all. The only effect as @MGTOW mention above is that a stroke on a kick drum will rarify the surrounding air instead of condensing it as a real kick drum would.

I don’t think I would notice a system out of phase. (What I’m sensitive to though is swapped left and right channels, if I’m familiar with the music.)
 
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Mr.Ian

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The graff is fully balanced, with phase inverted the speaker cones will pull in when they should push out, but in alk honesty i doubt you will notice the difference. The simple fix is to swap the speaker leads at the speaker or power amp, connect positive amp out outs to negative speaker inputs and vice versa for the other lead
 
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egg1dog

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The graff is fully balanced, with phase inverted the speaker cones will pull in when they should push out, but in alk honesty i doubt you will notice the difference. The simple fix is to swap the speaker leads at the speaker or power amp, connect positive amp out outs to negative speaker inputs and vice versa for the other lead
Thanks I will give that a go, much appreciated
 

MGTOW

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I am not familiar with the amp in question but it is difficult to see how a push/pull valve amplifier can be fully balanced. Perhaps someone can explain?

Absolute phase on playback is contentious, some people seem to think it is important, others not. I must say that, in terms of hifi playback it has never troubled me.

When recording it is vitally important, going back to my drum kit, I recall miking a kit with an Electrovoice RE20 on the bass drum and AKG Condenser mics on the overhead, fortunately the desk had phase switches on each input channel, so qickly sorted.
 
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Gray

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(What I’m sensitive to though is swapped left and right channels, if I’m familiar with the music.)
Me too.
I was once surprised to hear a reversal from a radio station - almost certainly not unique, but, as you say, when you're familiar with the music, you notice.
 
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Beobloke

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Hi all,

I am currently selling some kit for a friend but I am seriously thinking of keeping the Graaf GM50B Integrated for myself as it sounds utterly amazing - to be honest I've never heard dynamics or transparency like it in my lounge!!

Now on just checking over the amp and connections last night I spotted a picture of the xlr input wiring on the back of the amp(see pic) I only have my cd player connected via balanced interconnects.

Pin 3 is positive, this is normally negative with pin 2 normally being positive?

So I should be getting a specially made xlr interconnect with the positive and negative pins reversed at the amp end but am reluctant to change anything due to the sound I am currently hearing. I've read if connected out of phase there will be no bass but I have more bass than I have ever heard on my Usher speakers?

Has anyone else ever had this predicament?

Thanks, Paul.
You only get the lack of bass if ONE channel is wired out of phase. If the left and right connection leads are both reversed then two wrongs effectively make a right and you probably won't notice.

Obviously you've still reversed the absolute phase of the signal but very few people will ever notice that!
 
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Strider

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Balanced Phase is one of the only electrical connections I know of where two wrongs do make a right..
sort of.:geek:
 
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