anyone have experience w/magnum conversion 4 Rogue

I had a Rogue 88 upgraded to a Stereo 90 and it was an astounding difference in amplifier power and sound quality. In fact, the upgrade was so good that I couldn't tell it from a new Stereo 90. It cost me $1,000 at the time and it was well worth it. The Magnum version is far superior to the standard version. They just use better parts and the quality of sound is apparent because of it. If you really like the Cronus, for $600, I would consider upgrading it instead of investing in some new gear that will probably cost you around $3,000 or more to sound as good as the Cronus Magnum version.

I just upgraded my cronus and am very pleased. I drive Quad ESL988. Noticed better bass control, richer overall sound.

I have shipped my Cronus off for the conversion and haven't gotten it back, but I did spend a few hours listening to a new one at my local dealer driving a pair of Maggie 1.6's just yesterday. It was fresh out of the box, but my impression was that it was a much more refined unit than the basic Cronus. The sound of the new model was in the Audio Research ballpark, which is very nice territory.

Personally I liked the standard Cronus very much. I have had it for about two years now. Like you, I was a little nervous about having it "changed." I was particulary nervous about going to the KT-90's. But after spending a few hours with one of the new ones, I am feeling better about the idea. At this point, I'd have to say it is a lot of amplifier for the money. This is just initial impressions, but I'll write more when I get my unit back and spend some time with it.

Holymackerel, I'm curious why you went from EL34's to the KT90's. I didn't even think that the Cronus circuitry would allow for this substitution. I went from the KT88's (SED Winged C) to the KT90's (EI & EH) in my Stereo 90 and found that the entire musical presentation was more pronounced, especially in the bass frequencies. I thought it was the best tube I ever used until I started to sense that something was missing in the music. After a a month or so, the music sounded congested in the midrange, like some of the music was compressed or missing, like there was a lot of empty space in the soundstage. I went back to the KT88's and I found that although it wasn't as powerful a sound as the KT90, it was a more pleasing presentation to my ears. It was just more musical and palpable and I never went back to the KT90's again. Simply amazing how personal and subjective this hobby can become.

As I said, I was nervous about going to the KT90's. The Magnum upgrade for the Cronus includes EH KT90's. That is part of why they get 90 wpc out of the Cronus. You can actually drop KT90's into a standard Cronus, yes. You can also use KT77's. Rogue also upgrades the power supply, by the way, "to enable use of the KT90's" although the stock Cronus seems to have plenty of juice. I talked to Rogue about the KT90 before going ahead with the conversion. They said they had been very pleased with the results they were getting with the newer EH KT90's. Obviously I won't know until I have had my upgraded unit for for a while and the proof will be whether I have stuffed the EL34's back into the upgraded sockets in three months or not.

On the wilder side, I've even used EH 6550's in my un-modified Cronus. You have to take the top plate off to do this, so I only did it for a short time. Works fine. I talked to Rogue about having the holes in the top plate cut our a little larger to accomodate the 6550's or kt88's for that matter and was told that I could do that, but that I shoud really give the KT90's a try first. So that's what I'm going to do--give the KT90's a try. Will let you know. BTW, if you do try substituting some of these tubes for the EL34's, make sure to re-set the bias first. There is a big difference in the current draw between some of these tubes, but the Cronus can accomodate them, IF you re-set the bias.