Using 2 Amps with Audible Illusions Modulus 3A Preamp

Why not just use the sets of output jacks on the preamp

Im doing the same here with a L3 Bi-amped

On my l3 there are resistors on the CD input to reduce Glare.

I split the outputs of my Lazarus tube preamp in a bi-amp configuration.  I use the solid spitters vs the y-adapters but either should do the trick.

According to the Audible Illusions Modulus 3A manual, its output impedance is 1.2kΩ. It is best to check that the input impedance of the two power amplifiers paralleled should not be lower than 12kΩ, otherwise it may cause low-frequency roll-off.

https://www.allaboutcircuits.com/tools/parallel-resistance-calculator/

How did you reach that calculation imhififan?

When you responded to my previous post, I edited it, sorry!

A general rule of thumb is that the amplifier input impedance is at least 10 times higher than the preamp output impedance to provide a flat frequency response.