Svetlana EL34 Matched Power Tubes Hard/Blue Duet

i got these tubes in the marshall jcm-2000 tsl602 along with my classic cry baby by dunlop, tube screamer, and my epiphone lespaul traditional pro. the amp uses marshalls wolverine 80 watt speakers. my friend told me the tubes were never changed and he runs the amp very hard and they havent gone bad yet. on the clean channel the tubes have a very even sound with very vocal and lyrical mids. they provide a deep resonant bottom and clear sparkling highs. highs sometimes get a little piercing but only on this channel. i usually turn the treple back a bit or my tone down slightly to smooth them out. the od1 channel has a very classic rock sound only a bit more overdriven probably due to the tubes being softs. the bottom end is very deep and tight especially when you hit that sweet volume on marshalls. the response between the high to lows is fairly even and they really provide a good tone. the od2 channel very high gain and the tubes defintley clean it up and keep everything quite. i have to in front of the amp just for it to start to feedback. the tubes give the palm mutes give a nice chest thump on power chords but they arent overwhelming. the articulation is very clear and precise. every note gets heard even when i turn the drive n my tube screamer all the way up with all of the gain. when i drop tune it feels like the tubes really like it and keep everything together. i do shows and i record with them and so far they havent failed yet. hope this helps guys.