What is a non-active pre-amp stage?? Are their advantages to this design??

I just re-read the original post and realised I'd forgotten we were talking about an integrated amp (not a passive preamp). You will be able to trust the engineers have taken into account the impedance internally (and so can disregard most of what I just said), the unit has 10k input impedance so that should be fine for most, if not all sources. 

I still think that sometimes it's worth using active components to overcome the limitations of passive ones e.g. if you want minimum noise levels 10k pot has minimum noise of -115dBV, a 500Ω attenuator has minimum noise of 127dBV but will require some active buffering. 

Apologies if I've added more confusion, I should have re-read the original post properly before responding. 

I still think that sometimes it’s worth using active components to overcome the limitations of passive ones

If there are no impedance issues "limitation" as you say, then a passive will sound better, more transparent, better dynamics, and less coloration/distortions. (see Nelsons quote)
And aren’t we searching for the Holly Grail?
Why compromise plus the expense with an active, why not strive to get the passive right? Or better still going direct if it allows it.

Cheers George

I don't think it's as simple as passive is always better... the rest of the amplifier is active, just no buffers or gain on the input. There always needs to be a reason for the extra components though.

It's fairly easy to produce a very low distortion amplifier with either architecture. As I described, active components can help to minimise the noise floor which for me is important (I'm not talking about hiss or interference) as I like that pitch black background you get from an super low noise amplifier.

I guess we're all looking for our own Holy Grail, but the chances are we won't all agree on what that is. Personally I go for the solution that delivers the most accurate representation of the input signal (just bigger).

Apologies to the OP for going so far off topic... it would have been much more useful if I'd actually heard the amplifier and could just say it's great!