I have a Hartke 30w bass amplifier with preamp-out and speaker-in jacks. It has a decent tone and plenty of bottom and head-room for the space (small theatre). But I also have a new Vox vt20x (20w) with a tube and lots of modeling and effects.
I want to use some of these sounds from the guitar amp with my bass (the flanger in particular is really nice). Now the vox doesn't have a speaker-out or a line-out, just a headphone-out which doesn't seem promising.
I've tried plugging the bass into the Hartke, then running the preamp-out into the Vox input and it does seem to give me more shape on the lows and more head-room. And I'm guessing that I'm not going to blow any circuits by doing this, but is there a better way to either beef-up the low-end from the Vox or get a signal out of it that I can feed to the bass speaker?
Edit: tried the same chaining setup again and there is still sound from the bass speaker. So I am getting some degree of splitting. There's also a line-out on the Hartke with similar result.
Update: I didn't try either of the suggestions, but went ahead to rehearsal with the preamp-out jury-rig. The result was too noisy for the space. So I reduced my gear to just the Hartke amp and an envelope-filter pedal. For future shows, I think the real solution is a smaller Bass Amp, like 15w, so I can drive the amp more into its sweet spot. With the 30w, I have my volume on 3, and any more would be too loud. More details in my facebook post.
I cannot judge between the 2 answers yet, but either would probably be less noisy than what I tried. But the real crux of the issue for this show, is that 30w + 20w is just too much amplification for the space.