If you are going to connect three tuners, select a three way splitter... four tuners, a four way. Then run an uninterrupted cable from each splitter port to each tuner. The power insertion block for the amp will need to be between the splitter input port and the antenna.
The splitters at the big box home improvement stores are fine, Home Depot sell the Ideal brand which are fine.
If you choose a three way, one port of the three outputs will have less loss. Use that low loss port for the longest run of coax.
Resist the temptation to run one coax to a two way splitter, then on to the next set... another two way and on to the next... the signal at the end of that daisy chain will be far less usable.
Is this the amplifier you are using?
http://www.usa.philips.com/c/cables-...83h_17/prd/en/
If so, it's frustrating that Philips offers no information re. it's noise figure or maximum signal capability...
An all too common problem with consumer grade amplifiers. You own it, so try it. The indoor unit is most likely, just a power supply... the amplifier is in the outdoor unit. One with out the other will likely block all signals.