Classe CAM 350 upgrade for Conrad Johnson MF2500A?

I posted the question "what's the best amp, for music, under 1k used" and got multiple responses saying I should check out the cj mf2500 and after researching that amp on-line, along with a few others, I decieded that the cj mf2500 was the one that I would probably go with. I'm "auditioning" a classe ca-150, simply because it was offered to me today, for the next couple of days and if I don't buy it, I'd be interested in possibly buying your cj!

Had a CJ 2500A and it is a fine machine. A 2500 under 1K$ used would be a bargain. But if you can afford a few hundreds more for a 2500A, you would be geared on more long term enjoyment.

Thank you all for your comments and suggestions! Keep them coming!

I am happy with the MF2500A. In fact, I had two of them and tried bi-amping the Dunlavys but did not notice a big improvement so I sold one. But, as indicated in my post above, I am always on the lookout for the next upgrade which seems logically the Premier 350 but they seldom come up for sale.

Will check out the Rowland and Spectron, have heard the ML 23.5 but for my ears it was "too dry". Am eyeing the CJ CA200 as the "baby" Premier 350. One reason of coming back to CJ is mainly color matching my CT-5.

In some recordings, my main music system sounds just a tad on the bright side so I am contemplating to use Cardas (again) to replace my NordOst Valkyria ICs and Heimdall SC as opposed to upgrading to Tyr or Valhalla. For that kind of money, I may as well add some big ones and upgrade to e.g. (used) CJ LP140 monoblocks...choices...choices...

Doug99, as to your question about the mods, I did the easy tweaks first: soldering the drivers with Cardas Quad Eutectic directly to the wires, changed all screws holding the drivers to brass ones, then replaced the binding posts to Cardas CCGR-L type and the resistors in the main path of the cross over to (non inductive) wire wound resistors and reflowing the solder on the cross over whilst at them (replacing caps is less practical due to the bigger sizes of the film variants). The sound is more precise and resolution has gone up a notch and I would say, a slightly lower noise level. Absolute worth the time. One other reason not to replace the caps is that I have a pair of Duntech PCL 400 aka Black Nights as fronts in my HT setup (still trying to convince my significant other to swap them for the SC-IVs ) that, as you know, have decent quality cross over and driver parts. The vintage Krell HTS/KAV250a combo there drives the Black Nights very nicely. John Dunlavy has made some wonderful designs, but I wished he had more of an eye for aesthetics.

- Charles

I'm a bit surprised that you didn't notice a worthwhile difference running bi-amped 2500A's. I had a friend who went from using one pair of B&K M200's to two pairs of B&K M200's (which he had factory matched) with the Dunlavy SC IV's, and the improvement was much greater than either of us expected. It just wasn't about sheer volume either, inner detail, sound-stage width and depth, an overall greater suaveness if you will. I can only guess that it might have been due to more availability of more sustained Class A bias. BTW, I've used ss c-j in the past on Thiels (a not so very different type of speaker) and enjoyed the c-j very much with them.

It seems that as CJ designs moved forward in time their SS designs "brightness and detail" dial got moved up a notch in each iteration. The MF2300A (which I have) is mellower than the 2500 and going in the opposite direction the amp prior to the 2300, the MF 200 was much mellower and so on. I don't know where I heard it first mentioned but some one said that as a designer gets older their designs get brighter I guess because they can't hear the high frequencies as well...