Balance issue

[maxdog]

I'm not sure this is the proper forum for this, but since one of my components is a Modwright Oppo-105, I'll start here.
I am experiencing a balance issue in my system when I switch from balanced to SE with my preamp, and I'm baffled as to what is going on.
I have the Oppo driving a Ref 3, Magtech amp, and Magnepan 3.7's.
When I set the preamp in balanced mode, the balance shifts in favour of one speaker. It is obviously louder. In SE mode, it's equal.
This happens whether I use all SE cables, all balanced or a mix.
I returned the player to Dan several months ago, and he looked at it. Concluded all was good, and therefore I started to look at different components.
Put another amp in the system, problem still there.
Put my old GNS Resolution audio in, still there.
Swapped cables, no change.
This occurred with my previous preamp, and ARC LS15, so think I can rule out that component.

What I would like to know is "Is it possible for a CD player, etc, to output different levels through the SE outputs Vs the Balanced ones". In other words, is it possible that the signal is equal in the SE mode but not in the Balanced mode.

It's what it sounds like to me , but I'm not an electronics guy, so mu knowledge is limited.
Hopefully, I'll get some feedback here that will help me solve this dilemma.
When I swap cables at the output of the player, the issue changes channels.which has led me to suspect the player, but Dan didn't find any problems.
All advice appreciated, and thanks in advance.

BTW...Swapped the tubes as well, and no change.