Solid State Preamp to replace tube unit

@allenf1963 You are welcome. I strongly suggest either Brent Jesse  Brent Jesse Recording Supply or Andy Bowman at Vintage Tube Services. Both have fantastic knowledge, test equipment and in the case of Brent a 30 day warranty on nos tubes. He offers precision curve tracer matching for what i consider to be reasonable $. They will both typically have some Mc branded tubes as well.

The 225 and 240 use a very unique output transformer and in the case of the 240 amazing bandwidth and extraordinary low phase shift. Difficult, massive and certainly expensive to manufacture. The 275 is a brute ( in its day ) but imo lacks the 240 finesse. Finally… the 240 i run has been lovingly modified w HK style regulators and a bunch of Russian paper in oil capacitors… photos on my vintage system page

have fun.

The MC240 is a nice amp.  Rich, solid sound.  I had a pair of the monoblocks years ago and wish I'd never sold them.  I wouldn't worry about NOS tubes too much.  There are plenty of good new-manufacture tubes available, though they sure aren't cheap. ;-)

@tomic601 -- I have bought from Brent Jesse when I was getting tubes for my new Reisong A10 (absolutely amazing little amp -- I saw a review by Steve Guttenberg and thought "What the hell".  It cost me a total of $345 and that included shipping!  Paid another $120 for upgraded tubes.  Awesome amp for my bedroom streaming system).  I looked at your pictures...beautiful.

@elliottbnewcombjr -- I agree with your comment!  I try to keep a back up set of tubes for all my amps and preamps -- the MC225 is the only one I haven't purchased them yet.  Your suggestion makes great sense...start using the new set and keep the originals as back ups/nostalgia.

@dogearedaudio -- I bet those monoblocks were sweet.  I've seen a couple for sale and they aren't cheap!  And the tubes aren't either!

@ Jimbones

My personal experience - I have owned and loved playing an Ayre K-5xeMP preamp for many years.  Eventually, I wanted to try a good tube preamp and bought a ARC Ref 6SE.  

A used Ayre K-5xeMP now costs 1/10th of the new ARC, but is surprisingly good for the money. It is different than the ARC, but it has the clarity, tone and voicing of a high-end preamp, but different sounding than the ARC (SS has a little faster attach and decay).

At this level, you may want to demo a few to see which provides the best sound (to your ears, that day) with YOUR other gear.  If I were buying a used SS pre, I would also look at Pass and Classe, yet knowing what I know, I expect that the Ayre outperforms, dollar-for-dollar. 

Have you tried Accuphase Pre in the use market? The sound of Accuphase is very seductive, part SS and part Tube. I think you can get a used pre around your budget. I don't have their pre but I have their amps. Both class A and AB are both espectacular when I compare them with my McIntosh MC611 and MC1502 tube. A lot of detail without being harsh or analytical. I heard their Pre are the same.