tube fanatic

If it were my decision, I'd stay with the Cornwalls since you have total flexibility as to their positioning. I doubt that the K-horns would render any improvement which would be worth the expenditure. I failed to mention in my note above, that I have also owned Cornwalls which were used in a variety of room sizes/configurations.

A number of years ago I owned K-horns which were placed on the 15 foot wall of a 15 X 25 room. Because of the 45 degree angling, my listening position had to be about 10-12 feet from the speakers to achieve proper imaging. This was definitely a bit of a nuisance, as the preferred listening position would have been much farther back. I'd definitely consider this if achieving a wide, deep sound stage is important to you.

Stereophile had a glowing review of the Outlaw Audio receiver a few years ago- probably worth a look: http://stereophile.com/integratedamps/306outlaw/

Well, De-Oxit certainly does a great job; so, if you have access to some, use it by all means. However, if all you have is the WD-40, I would not hesitate to use that as mentioned before.

The noise you describe can result from a high resistance between a tube pin and the socket from oxidation. Before you ship the amp out, remove the tubes and clean the pins with a little WD-40 on a Q-tip. Wipe them dry and then re-insert. Also, be sure to rotate seldom used controls and switches as they are prone to oxidation as well. If all that doesn't work, then it's likely a defective tube.

With your system, using the Cornwalls, only 28.5 watts/channel will give you a sound pressure level of around 110 db in a 3000 cubic foot room. How loudly do you want to play the system? That kind of level would be nearly impossible to tolerate!!!

Your listening position is just as critical as the speaker placement. If you are listening far from the rear wall of the room, the bass response will be greatly reduced. If possible, try moving back toward the rear wall. Sometimes a few inches can make a huge difference!