Solid State Preamp to replace tube unit

@tomic601 

1961 -- Amazing. You have been the first person that responded to my post, so I did some online research today on my own. I discovered NUMEROUS comments in Forums and articles that said exactly what you said -- the MC225 and MC240 were legendary for being "easy" on their tubes. Especially those original Westinghouse tubes with the "Made For McIntosh" green print. Many people said they were still using the original tubes...60 years or longer. That is just astounding to me.

I dread the day my luck runs out on the McIntosh tubes. Last time I checked, there were still some NOS available at times, but it always worries me when the website says "Call For Pricing". I have thought about just buying a backup set while I can -- I can’t take the money with me! While I’m in a spending mode, I’ve also been looking for an MC240. I have always been told by my older McIntosh owner friends that the MC225 and MC240 are and were the best sounding amps McIntosh ever built. I compared my MC225 to a friend’s MC275 and preferred mine. Maybe it was confirmation bias, maybe not, but I’d like to hear an MC240 in my system.

allenf1963

buy a replacement tube set now, and an inexpensive tube tester, it will take the dread out of your life, listen without concern!!!

you could install the new ones and keep your old ones that test good as spares. It's always good to have a few spares so you can have music while you research replacements.

test the tubes you buy when you receive them, 

live near 07062, I'll test them here.

@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!