Connecting a subwoofer to a Joule LA-150

I would go with Brainwater's solution, I don't think you'll like the sound with the BAM between preamp and amp. Ask Bobby, he'll say the same thing.

Yes, Don is correct, the second output to the sub will be filtered by the BAM, not good, I forgot. Placing the BAM between the amp and preamp is still not a good idea, the BAM has a pleasant effect on the source's sound, placing it between the preamp and amp negates that. Bobby recommends keeping it between source and preamp. This is one of the reasons I don't use a sub with my Merlins.

Still, it seems I recall hearing about some Merlin owners successfully integrating subs into their system, and keeping BAM between source and preamp. I don't recall the method, perhaps someone else here does.

With only one source, Don's method works, the other preamp output won't be filtered.

With two sources you are using tape loop on preamp, both ouputs are filtered by BAM. using this configuration the BAM essentially remains between the source and preamp. I can't think of a way to maintain BAM between source and preamp and add subwoofer without it being filtered by BAM on preamp outputs. The BAM would have to go between the preamp and amp.

Yes, with two BAMs you could connect each source to it's own BAM, BAM outs into source ins on preamp, preamp outs won't be filtered. I'm also wondering if you could add a second set of RCA ins and outs to an existing BAM. Both sources would go directly into BAM, out into preamp, no filtering at preamp outputs. I think I asked Bobby about this some years ago, can't recall his comments. You could also use a balanced BAM (has two complete circuit boards), one circuit board for each source, outs into preamp ins. Preamp outs no filtering.