measuring balance

[denti alligator]

My Steremour II appeared to have the balance shifted to the R channel, so I used a db measurement app for my iphone, played a test tone from an LP and set the balance to where the test tone was giving me the same db on the app. I made sure to hold the phone in the exact same position for each speaker.

Great, right? Well, now I'm listening to a record and the vocals seem too far to the L channel.

Two questions:

1) Can where I have the volume set affect balance?

2) Is there a more accurate method for measuring the balance, perhaps using mono source and a AC meter?

Thanks.

[Doc B.]

1) Yes. Most volume pots have some imbalance at the lower level range. That is why we incorporated the balance control, so one can compensate for this as the pot setting changes.
2) Thus, there is not a whole lot of point in fretting over the precise balance setting at one pot position. The best way to deal with it is to use a recording with a solid center vocal and adjust by ear at the level you wish to listen.