On side subject...isn't krell non existent anymore? I thought remember reading the company is dying and last giant class a amps they designed was on complete recall cause of them litterly catching on fire and blowing up. Surprised Harman never bought them off but, they probably have no reason cause  Harman has mark levison.

I hadn't heard anything to that effect. The company's founder Dan D'Agostino was ousted over a fight with an outside investor that he had brought in, and he's now running his own ultra high-end company. But other than that, AFAIK Krell is still rolling along as usual. At last year's CES they introduced iBias, basically as a way to run Class A amps in a low power idle state as other floating/sliding bias amps like Karans have already been doing for awhile.

Why active preamps?

• Weak source. Need more voltage to drive power amps / speakers.
• Impedance mismatches between source and amp.
• Long distances between source and amps.
• Need handy volume control, possible with remote control.
• Want to color the sound, e.g. colored tubes.
• You have an unresolving POS source, so it makes no difference anyways.

Why not?

• Adding more crap to the chain = less resolving, less clear, more veiled, flatter sound.
• Want to avoid coloring the sound.
• Want to take advantage of super resolving DACs like Yggy.

Conclusion: avoid active preamps if you can. If you must color, do it with source or amp. Don't add more active crap into the chain.

Any specific models of balanced passive preamps (with remote) off the top of your head?

I've heard good things about the glassware audio kits (need your own chassis and connectors), and you can't beat the price: http://glass-ware.stores.yahoo.net/baat.html  I know a few folks have used the single ended versions in their bottlehead builds with good results. 

I've recently been contemplating building up a passive pre to put in front of my F3 clone, and I'm either going to go glassware or pick up a couple of the same really nice 2 pole 6 position rotary switches bottlehead uses in the mainline, submissive and beepree upgrade kits: http://www.alliedelec.com/1/products/37591-1-section-2-6-position-2-pole-rotary-switch.html  Picture of the wiring and details here: http://bottlehead.com/beequiet-stepped-attenuator-upgrade-for-beepre-specs/

Dave, name of the preamp in the pic?

Thinking about building one of these for my Mackies:

http://www.diyaudio.com/forums/analog-line-level/219342-help-choosing-potentiometer-passive-preamplifier.html