I did a little experimenting. I found that without the GFP, the sound was more focused, clearer and sharper than with the GFP plugged in. There was also less noise without the GFP. So, the GFP is out. With these results, why would I want to ever add a preamp to my only phono, 2 channel system? I guess that some add gain, but with less noise? What am I missing here?