Fisher 500C. Why pay for additional phono preamp?

I just discovered a way to make a second phono input for my second turntabe using the useless "tape head" input. Just take (2) 100k resistors and run them from the center input pins on each of the tape head inputs to each sides respective "phono ground" tie in lugs. The phono ground rides 10 ohms above chassis ground. Look inside the phono resistor network and it should be pretty obvious. Consult the schematic if needed. Works really well. The cost of 2 resistors beats the hell out of adding phono preamps and is way more convienient.
Doesn't the tape head input use different equalization?

How well is the level matched to the other phono input?

Are there any issues or side-effects?

I have a real nice 500-C that I would probably use as my main rig in my living room if two phono in puts were convenient. Hmmm ...