Double Bass HPF-Pre + PJB Flightcase: connections

[David Morris]

I have been amplifying my DB via Full Circle to fdeck HPF-Pre to PJB Flightcase for my quieter gigs, and have been pretty pleased with this setup. I read in some thread recently that our esteemed moderator Chris Fitzgerald uses a similar rig, but he plugs directly into his Super Flightcase then runs the signal post-preamp through the HPF-Pre via the effects loop.

How does Chris's method affect tone or volume?

The PJB has a claimed input impedance of 4 Mohm, the HPF-Pre specs state 10 Mohm. Wouldn't the Full Circle prefer the bigger number?

If Chris's method is "better" - why?

 

[Chris Fitzgerald]

I don't know that it's better or not, only that I prefer the sound. When I plug straight into the fdeck and then into the PJB, the sound is thicker on the bottom end with the HPF wide open (i.e. little or no rolloff) and slightly artificial sounding down there. It could be my imagination, but I imagine this comes from the Full Circle itself rather than from the fdeck pre. When I plug directly into the PJB front end, the sound is perfect (perhaps because the 4 Mohm impedance mitigates the lows, or just because the PJB preamp is a bad mammajamma? I dunno...) at lower volumes, then becomes too thick on the low end when the volume comes up. At that point, having the fdeck unit in the fx loop becomes invaluable.

As to "why" I think this sounds better, I'm not sure, but my ears tell me it does. It doesn't affect volume at all, as I can drive the limiter to exactly the same levels either way by adjusting the input level control.

 

[David Morris]

Thanks, Chris - that makes sense. I did try it both ways yesterday briefly and heard a difference but didn't have time to really focus on what the difference is.