boethius said:
I have a buzzing...like a ground issue with the STM 900. I've never had a buzzing with either bass before (Lakland 5 Deluxe with barts, Warwick Thumb 6 fretless). Is the gain stage uber sensitive? Or did something happen to my basses in shipping during my cross country move?
I find the Streamliner to be astonishingly quiet with my basses, but they're both active, and very well-shielded.
Anyway, your problem could be any of the above.
Tubes can go bad, and the SL has a VERY wide gain range, both to accommodate different basses, and allow for overdrive. Could be a bad cable. Could be the bass(es).
I'd start by checking gain settings- do your knob positions match typical reports on this thread? If you have the Master low, and the input cranked, it could amplify ground noise.
Next, I'd try eliminating components- use a known good cable, another bass, another amp...
Other things to consider would be bad house wiring, damaged power cord, or perhaps a loose or broken ground wire or poor shielding on your basses.