Newbee...put them back? HEY!
really here's the truth of it: in my upgraded sa-11 the audio section takes only two tubes and i did have the brown base RCA 5692's there and a pair of cheap sovteks in the other 6sn7/5692 section.
The sound was the best i'd had to date but i started to notice that the midrange was a bit analytical and once i did it really bothered me on some weaker recordings.
With four brown base tubes in my sa-11 the difference is major. soundstage larger, much better midrange, much less analytical, more bloom.
i now have to remove the amps from my rack and try switching things around along with the extra set of red base rca's. i 'am' very happy about the little treasure chest wellfed, and don't really feel the need to do the amps now but why not...
tough job but someone's got to do it.