[quote name='Osiris' timestamp='1455108448' post='2975935']
Dood, I always set the amp input gain so that it's just below the point where the pre-amp clips when I really dig in (I was under the impression this is the optimum setting?).
With that in mind, if the B3 is in-line between the bass and amp, then presumably and effects that boost the signal, like a drive setting, will also clip the pre-amp?
I didn't realise that fx loops have a stronger signal. Any reason for that? Surely they are optimised to work with all fx units (am I right in thinking that the implication is that some units work on different signal levels???)
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As Dood says, the fx loop operates at a higher signal level - 1V peak-to-peak is the reference level, whereas a bass will typically output 150mV peak to peak. That's so that power amps and rackmount gear all have a consistent level to operate at rather than having to cater for a wide range of input levels, it's just the preamp (and effects pedals) that deal with the lower level signals. Raising the signal level up to 1V peak to peak means that noise becomes less of a problem as if you have a bit of noise of a few mV, it'll be much more significant with a lower level signal than a higher level one.
Having tried a B3 in an fx loop myself, I can say that it wasn't happy.