|(This review is for the MA255, which is nearly identical to the MA252. Both have four inputs, and both have amplified outputs for one set of stereo speakers as well as one line level out. The MA252 has an XLR input whereas the MA255 has an extra set of stereo RCA inputs and no XLR)|
I use the MA255 to share a set of Palstar SP30 speakers with audio coming from a 1) Flex transceiver (stereo), 2) an Icom transceiver (stereo), 3) a Winkeyer WKUSB-AF (Mono) and 4) a PC (stereo). The volume of each device is adjusted with a dedicated knob on the MA255. There is no need to switch between the sources as the audio from all four is mixed together. If I don't want to hear a particular rig, I just turn its volume on the MA255 to zero.
I have limited desk space in my shack so the compact size and integrated audio amp in the MA255 was a good solution for me. I also wasn't trying to also share microphones, PTT and CW paddles. The only negatives I can think of are: a) it uses a 24v wall wart. I would prefer to wire it into the shack's 12v supply using powerpoles. b) I wish it had more inputs so I could add VHF radios etc.!
I'm still using the MA-255 in my shack two years after purchase, and very satisfied. I'd recommend it highly if you are looking for a simple way to share audio from multiple rigs with unpowered speakers.