I seem to recall reading some threads here as to one major sub contractor in China doing the assembly for a few major audio makers... one or two were from Europe, I believe too.
The rehtoric that got my attention was an allusion to one companies level of componetry being assembled was of lesser stature than another companies, yet the inferrence there was some substitutios either would or could be interjected to facilitate production... ex. two caps, same values, different levels of quality, being used interchangably, one to the other.
I thought that was plausable briefly, then was pretty certain, some Q. A. on the consignor's end would prevent that from occurring.... well, at least repeatedly.
Sorry I can't be more specific but those threads should still be live.