" said:

Your set up sounds more correct than Roberts since inverting would certainly
present a difference.


Probable differences could also be due to certain phase shifts between
amplifiers, that wouldn't be a problem when using an amp stand-alone,
but might be audible in this setup.

Also, there are inverting and non-inverting amplifiers.
In case of comparing both sorts, one channel has to be inverted first.

--

"Audio as a serious hobby is going down the tubes."
- Howard Ferstler, 25/4/2005