Discolored (rusty?) Allen screws on side of MF-2550.

[AnotherJohnson]

That can happen ... I’ve seen it with cars and other things that live outdoors.

[rff000]

One more follow-up. I called Conrad-Johnson and asked about the issue and the technician said I should just do nothing and leave it alone. That's what I thought I'd do anyway, but I wanted to doublecheck with the pros.

[AnotherJohnson]

Good advice since they are holding transistors to the heat sinks.

[Big Dog RJ]

Congrats rff000 on the MF2550, very nice amplifier.

As AJ very rightly pointed out, the SE version takes the performance to a higher level, even closer or equal to the Premier 350A in my opinion as well. It's an outstanding amplifier, and if looked after well, will outlast many generations of other highend SS contenders, that actually cost two to three times more.

The MF2550SE is so underrated it's not even funny. It can easily surpass a heck of a lot of amplifiers that simply run out of steam. The solid power supplies and high current capacity, provide very stable current to drive reactive loudspeaker loads. I was using one to drive my CLX's for a few months when I had to send my tube monoblocks for an upgrade/service. The MF2550SE handled the CLX's so effortlessly, they performed nearly sounding like horns!

I was also thinking on the exact lines of what the CJ techie said to leave it alone. I totally agree on using a tiny bit of WD-40 if you must, just to get rid of the rust, make sure the Allen screws are cleaned out. As AJ suggested, makes perfect sense.

Lookafter that amplifier, it's one of a kind, no longer made and very extraordinary. Enjoy it to the fullest!
Remember you can always upgrade to the SE version when finances permit down the track, CJ will gladly do this upgrade for you. I highly recommend the SE version, it's worth every penny. It's probably one of the best SS amplifiers I've ever used, apart from the Momentums or Relentless monoblocks that cost 200grand! So you get the idea of level of performance I'm referring to with the SE version.

Also give it plenty of running in, as those SS devices take a whole lot more hours to sound right and get going compared to tube amplifiers.

Have a good one mate, cheers and a big woof!!!
Oh! BTW, do enjoy those fine tunes!
RJ

[AnotherJohnson]

You do want to be very stingy with the wd40 if you use it. Penetrating oil may be a bad choice for transistor mounts. The more I think about those transistors, the more I think that either nothing, or De-Oxit might be a better choice. But honestly, doing nothing is a good choice.

[Big Dog RJ]

Yes, be very careful with the WD-40, only a tiny tiny bit.

I think De-oxit would be a better choice as they can just about clean any discoloured connections, speaker wire, contact points etc. This would be a better bet.

We're saying this only because you're concerned about those rusty looking screws... otherwise as CJ's tech has already advised, best be left alone.

Best, RJ