2. analog
  3. 127031-2195

Can I convert stereo to mono for a phono input

My preamp doesn't have a switch to convert stereo to mono.  I would like to switch a stereo signal to mono to set my cartridge azimuth (when using two channels out of phase, this method allows accurate balancing of the channels).  Is there a way to build a simple converter: two RCA female plugs taking a stereo signal and mixing it to mono, output as two RCA male plugs (mono signal)?


I have a test LP that provides a stereo track (test signal) with the two sides out of phase.  All I would need to do is feed that through the mono converter to set my azimuth. 

Thanks for any advice.  Peter

peter_s
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almarg
9,670 posts
 
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


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almarg
9,670 posts
 
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

lewm
13,230 posts
 
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.

fleib
1,124 posts
 

Why do things the easy way when you can do them the hard way and risk your equipment at the same time?

**Azimuth Adjustment

Track 2 - 1KHz reference level, left channel only                            Measure right channel output

Track 3 - 1KHz reference level, right channel only                            Measure left channel output **

Analogue Productions Test LP (about $40)

peter_s OP
1,348 posts
 
My immediate goal is to get equal output out of both channels.  Right now the right channel is a bit louder than the left, and I can see this on the meters for my recording device.  There is no issue with me using a single in phase test tone for both channels at the same time, and using my meters to make the adjustment.  I would just rather do the "nulling" with the out of phase test tone - that is more definitive.
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