EL34 comparisons please


Hi, I have a Dynaco st70 which is stock and has the bloomy midrange sound that I like with Jazz. I most recently bought a Conrad Johnson mv52 el34 amplifier which sounds nice and I was thinking of trying some new el34s with it looking for more exaggerated midrange. Any suggetions would be great. Speakers are RSIII Infinity's and the tubes that I am using now are vintage Sylvania.
Thanks,
Guy
guycom
Just a further comment:--- When I bought the CJ5s,I pretty much knew nothing about any sonic differences between Svets and Siemans. The seller included both sets. ---He prefered the Svets so I did them 1st. For about 2 days.--- Then I did the Siemans; I never put the Svets back in;is what I thought of them. ----I do disagree with the one sounds better in one system; thing. I think if your system is up to resovling enough there is a pecking order. ----THIS btw; is just from reading here for 5years.---The knowledgable say the same thing over and over.The Svets are just lower in the pecking order--
Here are EL34 types review from the tube store site

http://shop.store.yahoo.com/thetubestore/el34review.html