New Pre or Integrated for 2nd system, thoughts?

some of the rotel, cambridge, nad units are nice for the money

I would go with a new/used preamp, with one exception.

NAD C 162 preamp - new, refurbished or used, $400 to $500 online. Typical NAD sound - musical and nicely rounded. good review here:
http://www.audioasylum.com/reviews/Preamplifier-SS/NAD/C-162/general/409399.html

Adcom GFP-750 preamp - highly regarded - buy it if you can find one used for under $500. Good review here:
http://www.stereophile.com/solidpreamps/133/

Rotel RC 1070 preamp - good, but not as strong as the other two IMHO, available for $500 new and much less used online. Good review here:
http://www.enjoythemusic.com/magazine/equipment/0601/rotel.htm

Here are the exceptions to the preamp recommendation:

NAD C 372 integrated amplified - used for around $500 (if you can find one). Powerful, musical, a hifi bargain. Good review here:
http://www.stereophile.com/integratedamps/1006nad/

Cambridge Azur 640A v2 integrated amp - this has won lots of praise and only $400 new right now at Audio Advisor, but can 120W into 4 ohms do the job for your Thiels? Over the top reviews here:
http://www.cambridgeaudio.com/product_reviews.php?PID=105&Title=Press+reviews

Other than the specific recommendations above, older NAD and Rotel preamps are options if you can find them in good shape.

No matter what you choose - I would save some money for a good power cord and some decent interconnects and speaker wires if you don't already have them. My view is that a decent preamp/integrated with a good power cord beats a slightly more decent piece tied to the wall via some lamp cord.

I haven't heard it, but the Onkyo A-9555 (integrated) gets a lot of buzz, and new comes in under your $500 limit.

It would be a stretch, but you might be able to find a Musical Fidelity A3cr integrated for near your price point.

Michael

I'd go for a pre rather than ditch the B&K. Whilst it doesn't double power into 4 ohms, it can still deliver 200 watts into 4 ohms which is plenty for the Thiels. They also have decent peak to peak current, so will work well into the lower impedance speakers.

As for recommendations, I agree with the NAD and Adcom recommendations above or possibly an MF A3 pre. Another possibility - I notice there is a B&K Pro5 pre + ST202 listed for $500 - you could get this combination and biamp with your current B&K - no question marks on the power in that combination!:)

the musical fidelity a3 stuff is rock solid ,usually more expensive and should be, it is beefier and better built, the newer stuff, 640 cambridge is the best bargain on the planet and yes i have one and one for sale..dwhitt

I have owned the Onkyo A-9555 and recommend it highly. It's a beast with a huge transformer and lots of reserve power. It's better built and better sounding than any of the NAD, Cambridge or Rotel gear I've owned at anywhere near the price.

Get the Onkyo. My experience matches Sfar. I've had mine for 6 mos. I like it better than most British integrateds up to around $1500, and certainly like it better than anything available under $1K. It has a very low noise floor and lots of transparency and speed for the money, while managing to sound warm and cohesive. It doubles its rated power into 4 ohms, and sounds bigger than its rating because of its incredible instantaneous current delivery (up to 80 amps). Nice ergonomic remote, silky smooth controls, heavy build quality.

Give it 100 hrs to run in, put a good aftermarket AC cord on it, and make sure you have your speaker cables terminated with bananas at the amp end. And leave it on all the time. It's only drawing about 1/4 watt per hour in standby and it makes a big difference on how nice it sounds when it's playing.

Just wondering if the Dreded Scott company ever made an integrated?