Can I convert stereo to mono for a phono input

You need the maximum AC voltage!! :) Same connection.

I had thought about suggesting that, Erik. But I’m not certain that maximizing the voltage difference between out of phase signals on the two channels would allow as precise a determination as nulling out their difference by adding them together.

Envision that azimuth has been optimized precisely, by maximizing the measured difference between out of phase signals. Then envision that a small misadjustment of the azimuth is introduced. It seems to me that even though the amplitudes of the two signals might become significantly unequal, with one becoming larger and one becoming smaller, their difference might not change much if at all from the previously established maximum. Whereas if they were added together they would no longer sum to zero.

Best regards,
-- Al

Al - what do you think of my suggestion #2 above?  If the signal is in phase (e.g. 1kz test tone), measuring the difference between channels with a voltmeter would give me an accurate zero, no???

Hi Peter,

Regarding your question just above, the following comment I made earlier applies. In addition to option 2, it also applies to option 3. The bottom line is I don’t know :-)

I would wonder if the corresponding lateral movement of the stylus would allow as precise an adjustment of azimuth as the vertical movement that occurs while playing an out of phase track would allow. Maybe it would and maybe it wouldn’t; I’m just not sure.

Regards,
-- Al

It looks like the currently manufactured Einstein phono stage has a specified output impedance of 50 ohms. While it may very possibly be ok to short its two outputs together with a y-adapter while they are driving opposite polarity signals (even though that would cause far more current to flow in the two output stages than under normal circumstances when music is being played and the outputs aren’t shorted), and I suspect that a lot of audiophiles would just go ahead and do that, that is a low enough impedance that I personally would very definitely NOT take that risk without an ok from the manufacturer.

Best regards,
-- Al

I am feeling intellectually lazy, but a superficial reading of this thread leads me to think that the OP may want to achieve EQUAL amounts of crosstalk, by the method described.  That's OK, but keep in mind that equal crosstalk of one channel into the other and vice-versa does not usually correlate with LEAST crosstalk of one channel into the other and vice-versa, unless you own the mythical perfectly constructed phono cartridge.  If your goal is least crosstalk possible, then this method may fail to get you there.