Any way to "improve" a Conrad Johnson MF 2500

Thanks for the responses. I am surprised that the Shatki Stone is considered snake oil, since the reviewer on Steroephile used it.....makes me wonder about the reviewer.

Chuck, I talked to the seller of the amp and he said he had both the MF 2500 and MF 2500A versions at one point, but sold the MF 2500A because it seemed to lose the musicality that he enjoyed in the non A version. He told me this after i already bought it, so there is not the concern his recommendation was colored by his wanting to sell the non A version. Can you tell me your experience when you upgraded? What speakers were you using at the time?

I'm seriously anti hum...I've been a serial "ground floater" for years (including pro audio live sound...although with electric bands the musicians may be mildly electrocuted) and even found a NOS "PS Audio Humbuster III" which really knocks out mechanical transformer hum.

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.

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

I'm late to this thread, but own both an MF 2500A, & a MF2250 ("non-A"). No hums with either. They're both very musical-sounding amps. I can't tell that the MF2500A sounds "better" than the non-A MF2250, except for the increase in power. And as I recall it's several hundred $$ for the upgrade....