* Copied and pasted from another post under "Amps/Pre-amps" forum: Best 5881 Tubes.
In a short answer to my own question, I dropped in a pair of NOS GE 6dj8 (6922)'s in the SP-3 and found a slight but very distinct difference. The GE's (similar in sound to the Philips imho) brought out a more "single ended" immediacy with a tad more "forward" presentation. The images are a bit more localized and a bit more transparent. Not whole bunch better, but a little. Combined w/ the 12ax7wb change, it is a lot. I'm sure that cost was a factor in selecting the stock tubes for the SP-3, but in all fairness, they did choose some musical ones. The stock tubes are very open and non-fatiguing, but they are in need of a bit of speed and texture (again imho).
Tubby
In a short answer to my own question, I dropped in a pair of NOS GE 6dj8 (6922)'s in the SP-3 and found a slight but very distinct difference. The GE's (similar in sound to the Philips imho) brought out a more "single ended" immediacy with a tad more "forward" presentation. The images are a bit more localized and a bit more transparent. Not whole bunch better, but a little. Combined w/ the 12ax7wb change, it is a lot. I'm sure that cost was a factor in selecting the stock tubes for the SP-3, but in all fairness, they did choose some musical ones. The stock tubes are very open and non-fatiguing, but they are in need of a bit of speed and texture (again imho).
Tubby