Quote Originally Posted by Old Guy View Post
Someone else please chime in, but in my experience the Behringer drives an upward mismatch without issues. So AFAIK going higher is better than lower...
Yes....OG is right.

The 150 ohms thing of the Behringer is actually "150 ohms and upwards", as the output is not a shunt-loaded type, unlike for example microphones, where the output is actually shunted by a resistive value (of the v/coil or trafo) at the specified impedance. The Behringer spec means that it can take a maximum loading of 150 ohms at its o/p terminals, below which the signal will suffer. So any upward value will be a good thing. This is a standard nature of any of the electronically balanced/unbalanced outputs, and the specified imedance is nothing more than a series resistor at the o/p, to prevent the device output stage from getting fried. So 15335A should be the choice.

@MerlinVSM

The e-bay link provided by AB (Altec Best) has one seller with 3 nos. of 15335As available for sale.