difference between an active and a passive preamp?

You tried the Canary with the NAD270? What is the sensitivity of the Quad
22s?
They don't need much power, do they? As for passive, I think you would need
something like the Goldpoint with a 10kohm pot and short ICs to drive the
NAD properly. I may be wrong about this, but I think tube amps are generally
better suited to passives, but if the Canary had a 50kohm pot, it would not
work too well with an NAD amp. I wonder if a used Cayin integrated will be
enough power (40 watts of so tubes) to drive the Quads. IMHO, if you want
tube sound you are not going to do with an SS amp, certainly not at your price,
and really even at higher price points.

Another active tube buffer that is getting some attention is from Dodd Audio.

I have found that my system when using some passives is more succeptible to noise (ie. RFI, grounding issues, etc).

Since this thread has in part become a "passive and buffered pre roundup," I thought I'd throw the Superphon SP100 into the mix. It may be older, but it seems to have some kind of following. Plus, there're currently two available in the Classifieds. Seems to be a passive volume control with a buffer stage.

Audioflyer67, have you looked at the Decware site? I haven't heard their stuff with my own ears, just noticed their reputation. If you're looking to gradually get into tubes and you're starting at just the preamp at present, take a look at this one: http://www.decware.com/newsite/CSP2.html

Until recently, the forum there had a bit of banter. I think Steve Deckart (owner) is happy to talk you with you about your specific needs. It's a fun site to explore and has plenty of interesting articles by Steve. They also offer a tube buffer, tube gain stage, and input selector. Put those together, and you have a versatile 6-input tube preamp.

I've got my eyes on the Decware preamp with adjustable voltage. Talked to Steve about it and it is a well designed piece of equipment. Can be an OTL headphone amp as well.

Stan Warren designed some great pieces. The SP100 is one of definitely one of them.