Anyone have experience with one of these?

My band lost our second guitar player, and we're trying to move on with one guitar. We have a lot of harmonies, so we're trying to make those work with the Eventide PitchFactor. The tone of the thing sounds AWESOME! Very realistic harmony sounds. The only problem is that on some notes, it plays the wrong harmony.

What's weird is that this only happens on some amps. It plays everything perfectly on half of the amps in Guitar Center, but it does not on the Peavey 6505+, which unfortunately is what I have.

I emailed Eventide about it. They said that his happens when the amp isn't receiving enough of of an input signal. They told me to try switching a few settings on the pedal, to put a boost in front of the pedal, and to try it with a different guitar. I've done all of this and have had no luck.

Anyone else have any ideas or experience with this problem?
I own a Pitchfactor, but haven't really delved into its harmony capabilities with my band yet, only mucking around on my own. I can't say I've noticed any odd notes when doing harmonies. I would just remember to check the settings to make sure you're using the right scale, ie. Maj, Min, Dorian, Lydian, etc.

The different scales might have some of the same notes because the key is staying constant, but obviously a few of them will have some different notes than your standard Maj/Min scales. That's all I can really think of without having used the Harmony features a ton myself, though I imagine this is something you've already looked at. Are you running the PitchFactor through an effects loop or out front?
I'm running it though the effects loop. It doesnt sound very good through the front of the amp.

Definitely on the right scale settings. I have it set to 3rds in the key of D minor (D, E,F,G,A,Bb,C). Every time i hit an F, it plays a Ab instead of an A.
Hmmm, not really sure what the deal would be.

Is there a general setting for Maj/Min besides the key setting? Because F to Ab would be a minor 3rd, F to A a major 3rd. So maybe there's something bypassing the key or something...like reading it as Dmaj? I'm honestly not the most versed in theory. Either way the A should still be there, whether it's Dmin or Dmaj (although I guess if it was set to major, and you played an F, it might register a semitone down, since the actual note of Dmaj is F#, and you'd have moved it down a semitone....I'm rambling about things I don't know enough about).But you said it worked fine on other amps?
Yeah, i've been emailing eventide to figure it out.

turns out that it has to do with the input signal from the 6505's effects loop. The PitchFactor needs x amount of input signal to harmonize correctly. I guess that means that some amps have enough input in the effects loop, while others don't. Sucks for me cuz I have a 6505. I guess I need to keep trying to figure out what to do