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Any way to "improve" a Conrad Johnson MF 2500

I recently purchased a 10 year old CJ MF2500 amplifier. It is in perfect condition and it sounds excellent, but I noticed a hum coming from my speakers when it is turned on. It got me thinking, since there is no way to upgrade the power cord, if there was a way to "refurbish" or update the amp. I don't know if that is something normal for a solid state amp, but it's sounds so good and is in such good shape that I thought I would see what the rest of you thought. It would be nice to see it work for another ten years.
jeffatus

Showing 4 responses by czbbcl

czbbcl's avatar
czbbcl
1,752 posts
 
Upgrade it to a 2500A if it isn't an A already. The "A" mod improves the amps speed and detail. You have to send it to cj to get the work done but it is well worth it and while it is there they can go through it.

Chuck
czbbcl's avatar
czbbcl
1,752 posts
 
When I had mine upgraded it cost $500 plus shipping there and back; well worth it.

Chuck
czbbcl's avatar
czbbcl
1,752 posts
 
I was using Thiel 3.6's at the time along with a premier 16lsII pre-amp. The amp became more detailed and faster while retaining the typical cj 2500 sound. It did require about 20-25 hours of burn in. The non A version smoothed over the details of the music seemingly masking it. I like to hear everything in the performance something my current system does very well(Cary SLI-80F1 / Focal Be monitors).

In the end it depends on what you are trying to improve or what you don't like about the amp.
czbbcl's avatar
czbbcl
1,752 posts
 
Is the hum coming from the speakers or the amp? The transformer in the 2500 does have a propensity to hum.If you placed the stone on top of the amp it is probably dampening the cover which in certain circumstances can amplify the hum.

Chuck
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