Preamps for $300 to match with B&K st-140?

I'm not familiar with the diamondbacks. I would suggest avoididng interconnects that are very high in capacitance if you use a pre-amp with a high out-put impedance into the B&K ST-140. Of course the length of the interconnect will have to be factored in.

I got the amp today and posted about it. I hooked it up to my integrated as a pre. The diamondbacks sounded awful. Im now using Synergistic Research Alphas between amp and pre. Im looking for a nice cheap neutral to mellow pre. I have my eye on a NAKAMICHI ca5a2 pre. I want a little more bass and clarity. Any other cheap suggestions?

How about an Adcom 565 preamp. These sell for between $200.00 and $300.00 used.Known for it's neutrality..it will probably do the trick.

The truth of the matter is there are very limited choices in decent inexpensive pre-amps. The B&K pro MC 10 seems to satisfy all your requirements and would probably be the safest recommendation with regards to compatability. Please keep in mind that a new/different pre-amp may work differently with other interconnects. My expereince with B&K with regard to customer service always been very positive. B&K is a well established firm that should the need arise, will probably be there.

I bought a Dared SL-2000A tube preamp last week. I purchased it for a second system that I don't have together yet, so I put it in my main system. I have to tell you if you can get away with just 2 inputs and no phono, this pre will be hard to beat in that price range. It can be had for a little over $300 brand new(I payed $330 total). It comes up weekly at auction here and on ebay. It even has a little keychain remote.