I'm quite frustrated with my R40. Here, back in August, I posted a problem that many of you assisted me on
Fender Rumble Club
Fender Rumble Club
But the issue has persisted. I have now tested my R40 with other basses, in various settings. I took my bass to a store and played another R40, and it had the same kind of oscillating waves at the low end, mostly on the E string (tuned to E). It gets worse when I play a series of very low notes in tandem (e.g. "Riders on the Storm").
I've had the amp seen by a GC employee and the shop that sold me the amp. No one could rectify it, and the GC guys really didn't seem to care much.
The volume is not high, Vintage/Bright/Contour off, even with none of the EQ settings past 10. Experimented with all combinations of Gain/Master.
In my original post I mistakenly said "bridge pickup only" but it's the neck only. Turning up both pickups deadens and mutes the overall sound, but removes most of the problem. I use fat flats on a Jaguar SS bass.
I'm simply trying to use my R40 as a practice amp at moderate volumes, and it's frustrating that I here Wubbawubbawubba every time I play "Three Little Birds" or "Theme from Shaft."
The only thing I haven't tried is GonePlaid's batting idea.
But, it seems everyone else has no complaints about their R40. It shouldn't be that difficult for me to get a good sound with normal conditions.