I have been thinking about tri-amping, so this topic has been on my mind.
Rightly or wrongly, I don’t wish to put a digital component in the stream.
An interesting device I’ve seen can be found at this link. https://sublimeacoustic.com/products/k231-stereo-3-way-active-crossover
I have purchased, and I’m currently having these devices checked over and cleaned up. Firstly, a Sansui AU-5900. I love this vintage integrated amp, and it produces a sound very pleasing to me. The key piece is the Sansui CD-5, A three-way crossover, with variable crossover points. I plan to use the pre-out on the integrated into the CD-5, and then use the Integrated +2 additional amps. Additionally, I have purchased a Sansui BA-90, and a BA-60 for amplification. Some of the questions I have: what crossover points?… good thing the CD-5 is adjustable. Also, do I want to run the highs, lows, or mid range back into the integrated?
If anybody wants to discuss this rare, vintage, and quirky set up further, feel free to DM me, I don’t want to hijack the thread. But I am actively in the process of figuring this out.
Good luck to the OP, I fully support that you need to separate the signals and have your amps only drive the separated frequencies.