What tubes for ST-70


What tube or tubes would make the biggest change in sound on this amp. The GZ-34, 7199's or the EL-34's. This amp is a Dynaco ST-70 rebuilt by Will Vincent. Also what would i gain or lose by using KT-77's instead of the EL-34's?
Thanks,
Tommy
tommy583
Ok i put in a quad of the Svetlana EL-34 winged C, RCA 7199's and a GE GZ-34. The sound is alot smoother overall. I do think i lost a little bass when i installed the EL-34's. This leads me to belive the old tubes were KT-77's. The soundstage is a little wider and higher. The top end is more layed back and not harsh at all. I think i'm going to get the Mullard GZ-34 and see if that makes a differance. Over all i'm pretty happy with the sound, just looking for that last little bit.
Your going to find that the KT-77 has a faster, more aggressive bottom end vs. the EL-34. This is also true with the MK-3 amps when the 6550 is replaced with the KT-88. You will also get a bit more power output out of the KT-77 vs. the EL-34. When I had Mk-3's I would also keep them in Genelex KT-88's. That was a while ago when they were still available and reasonably priced. G
I've seen some good things about the remake of the Gold Lion KT-77's. I may try a quad of those next. I've seen them priced around $180-$200 a matched quad. I wonder if they are worth it though?
Well guys my tube rolling is done for now. In the end i settled on a pair of RCA 7199's, a quad of winged "C"' el34's and a Mullard fat base gz34. While the 7199 and el34 tubes were an improvement over the tubes i had to start with, the gz34 brought the amp up to a new level.
I could not belive the improvement i heard after i installed this tube. The bass is much more full, the treble very smooth and the mids are to die for. I'm just glad my local dealer doesn't charge the crazy prices i see on the net for these tubes. But in truth if i spent $150 for this level of improvement i wouldn't be disapointed.