Preamp's 2 to 3 Vout output typically operates in a large signal region. It's more difficult to determine the preamp's non-linear behavior as a function of Vout vs Frequency, vs complex input impedance of the amplifier.
You'll have to try the synergy between an AV8801 and the Outlaw amp. In my situation, I thought that Ayre 5-Kxe completely sucked driving my Gemstone amp when I bi-amped it. The sound was compressed and anemic which lacked life. Where, my inexpensive Outlaw 1050 receiver has excellent interaction. The Gemstone is spec'd at 23kOhms input impedance and looks like a 11.5kOhms load when bi-amped.
Thanks this is good information.
Since I have not bought an amp yet, it gets to be a hard choice.
For my Revel Salons which dip to 3 ohms so they like current.
The Outlaw 7900 has been confirms at >10K ohms input impedance.
The ATI version is more money but they have a different input stage that is 28K ohms.
So there is a chance. Both amps are 300 WPC into 8 ohms and 450 WPC into 4 ohms.
The Outlaw 7700 is significantly cheaper and is 200 WPC into 8 and 300 WPC into 4.
It is spec'ed the same as the ATI2000 series with an input impedance of >28K ohms.
So if bi-amping is OK with this processor driving 14K ohms, then I am OK.
In the Home Theater Mag review of the Parasound Halo A5, they felt the A4 had a more detailed sound than the 7900.
However, the Parasound has a very high impedance: 47 k ohms unbalanced; 94 k ohms balanced.
I think it is less likely that a good A/B sound that much different.
So I am developing a theory that input impedance might be involved.
This would explain the different performance experienced when testing these amps.
A lower input impedance amp might not match as well with all preamps.
What do you think?