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Phase inverting problem

Hello,

I have a Conrad Johnson PV-12A pre-amp. It is phase correct for the phono stage, phase inverting for the line stage.

My power amplifier is a conrad johnson MF2100. It is phase correct.

So my first idea was to connect the speakers to the power amplifier the wrong way (black to red, red to black) and then connect the cartridge the wrong way around as well (R: + and - reversed, L: + and - reversed). Then the phase should be correct for everything.

But there lies the problem. When I switch the connections on the cartridge, I get a really loud hum, makes the music barely hearable. Perhaps it has something to do with the fact that R- is connected to the cartridge body, it is some kind of earth? Anyway, switching the connections on the cartridge is not an option. So, what to do?

My only idea so far is, seeing that I only have one line input (cd), is cutting open the RCA cable and switching + and - of the line, and connecting the speakers to the power amp the correct way. So, I'll do just that. But maybe there's a better solution that I'm missing. Any ideas?
swaf
tbg
5,263 posts
 
False, but I still say we are guessing that recording engineers randomly chose polarity.
geoffkait's avatar
geoffkait
23,365 posts
 
No, recording engineers wouldn't invert polarity or compress the sound.



How do you check your system for correct polarity? - Use a disc with "correct polarity," of course? Ha Ha Ha
tbg
5,263 posts
 
No, no recording engineer could do anything but randomly choose polarity for her mics. Do they flip a coin? Are you sure it is an unbiased coin? What exactly is the correct polarity? The opposite of the wave onset at the mic?
atmasphere's avatar
atmasphere
11,753 posts
 
Recording engineers do not take note of whether their mixing board or recorders are inverting or not. Nor does it show up in the manuals for such.

The simple fact is that a recording may or may not be absolute phase inverted. There is no coin, no decision, the issue never comes up. When you send the recording out to be mastered (in the case of LP) you have no idea if the result will be inverted or not. For example the manual for my Westerex stereo cutter system does not mention a thing about it. Neither does the manual for the Masterlink (a digital setup that can do mastering) or the various recording programs we have on computer. Its not a consideration in the studio. Neither does it show up in the manuals for our analog recorders. Its just not a consideration.

So you can be assured that 50% of all recordings are in phase and the other half are not.
almarg's avatar
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almarg
9,670 posts
 
So you can be assured that 50% of all recordings are in phase and the other half are not.
Ralph, to what extent do you feel that holds true for simply mic'd classical recordings that are recorded in halls, and are produced by labels that are audiophile oriented and/or high quality?

Best regards,
-- Al
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