I agree with Millercarbon, use the KISS approach. You don’t have the ideal pre and your using different amps. IMHO, the Alpeh 5 is not the best match for the Dunlavy’s with what I believe to be a 3 Ohm minimum impedance.
I suggest you sell both amps, and get one more appropriate for your needs.
If you absolutely want to bi-amp; get a different pre with dual identical outputs that mate with identical matching amps that better suit your speakers.