Can I convert stereo to mono for a phono input

Thanks guys.  I get your point here. I think it's worth getting the azimuth right for its own sake.  If it solves the problem, great.  If not - hmmm - what ARE the other options?  This is definitely happening within the cartridge, as I can swap L&R inputs into my phono pre and it follows the swap.  Best, Peter

... azimuth adjustment should not be done in hopes of equalizing channel output.  (I actually wondered whether that was your goal, but I figured Almarg would have warned you off it before me, if that was the case).

Thanks Lew, but you give me too much credit :-)

(Especially when it comes to non-electrical things like cartridge and tonearm adjustments).

Best regards,
-- Al
 

peter_s

If not - hmmm - what ARE the other options

First, I'd make certain the imbalance is in the phono cartridge and not in the phono stage itself. No cartridge is perfect, but a good cartridge really shouldn't have an audible channel imbalance, imo. If it were a new cartridge, I'd return it to the dealer. The only other solution is to just replace the cartridge or use the preamp's balance control.

I haven't noticed it as audible, but it is visible on my recording meters.  It follows the cartridge leads, so it is upstream of the phono preamp. I'll have to look at the meters to see how many db off it is (they may be expressed as VU).

I would think that the read-out of a recording meter is very unreliable as to assessing channel balance.  First, the needle is bouncing around.  Second, you have no way of knowing how the material was encoded into stereo, meaning the fault may be in the recording.  Further, what do you know about the state of calibration of your meters?  IMO, if you don't hear the problem, why drive yourself nuts over a few dancing meter needles?  Try feeding each meter separately with a single signal; you don't even have to know for sure the voltage or db, so long as it is the same signal fed alternately to each channel.  This way you might determine if the meters are equally sensitive.

If the cartridge is fairly new, you could make a case with the dealer to replace it, if all else fails.  A decent cartridge should have inherent channel balance within less than 2db, but I don't know what bible that is written into.

By the way, as to your response to my earlier diatribe, getting the azimuth "right" is not going to cure your channel imbalance, if indeed there is one.  That was sort of my point.