Rectifier Recording Preamp being illogical

[Given To Fly]

I have a Mesa Rectifier Recording Preamp that has been both a blessing and a frustrating chunk of steel! :x When I've used it for recording direct, the clean channel is actually fantastic. The Lead channel is where I run into problems though. The tone is rather bright to say the least. I assumed my monitors were at fault because the Rec. Rec. Preamp sounds great through my Roadsters power amp. Well, I recently plugged my monitors directly into the Recording Preamp and it sounds awesome! I'm using Tannoy Reveal 601a's which have a rather high frequency range (30kHz) but its easy to dial back the end when the speakers are directly connected to the Preamp. When I'm recording, (connected to an Apogee Duet 2 w/preamps bypassed,) there is an extreme increase in the high frequencies. I use the Apogee with a D.A.V. BG-1 preamp and I haven't had any problems (the source sounds like the source). I know the Rec. Rec. Preamp is rather fickle but the tonal difference between directly connecting monitors to the outputs (I tried both) and connecting the Recording Outputs to my interface for actually recording are so drastic I'm beginning to wonder if I'm doing something wrong or if the Preamp responds better to certain pickups? Any advice would be most appreciated! I've read the manual a few times and will probably re-read parts again. Like I said, its been a blessing for certain applications but a good high gain tone is probably the hardest to dial in.

For guitars and pickups I'm using:
Ibanez RG2228 w/808x's
EBMM JP7 Cl/LF
Ibanez SCR220BP Stock V1 and V2 humbuckers.

So I'm using fairly high output pickups with the exception of the V1 and V2's.