Hi, I'm shopping for a reverb tank to add to a vintage mixer and started looking at the MOD tanks which seem to have pretty positive reviews with lots of different sizes and input/out impedances available. From what I've read the impedance is fairly important, so I want to make sure I'm buying the right thing. The mixer preamp section has what looks to be basically an RCA-port effect loop which does not specifically say it is for a reverb tank or any other particular purpose but a spring reverb is what I'm hoping to use it for. Here are the only specs I could find but seem like they might help: Does anyone know how I can interpret this? What is the difference between the "for use with" and "actual" figure in these examples? Thanks for any help here or any other helpful hints you might have for me, reverb-tank-wise.