Resistor in phono stage

The wrong resistor will give you the incorrect loading for the phono cartridge you're using with the PH3SE.

Thanks,would that effect the sound as too bright,too flat,Im not sure.

What do you mean by "wrong resistor"?
What cartridge(s) are you using, and by what criterion do you think the load resistor is wrong?  If you have an ohmmeter, just stick one probe into the RCA phono input jack and place the other probe on the outer barrel of the RCA jack; the resistance thus measured will be the value of the load resistor, unless there is a SUT in the signal path.  I don't know what the value should be for the PH3se.  The standard for MM cartridges is 47K ohms.  MC cartridges typically are run with more of a load (meaning a lower value of load resistance, down to around 100 ohms in some cases).  

The ARC PH3SE in a MM only phono stage.  It has a factory set fixed output of 54db gain, 47Kohm impedance and 90pF of capacitance.

You can change only the capacitance by soldering in different values of resistors.  I would make sure if this has even been done.  I have owned several of the PH3 and PH3SE units and none of them had ever had a resistor soldered in.

Here is an excellent white paper on loading:

http://www.hagtech.com/loading.html