EL34's with more bass than KT90? That would seem unlikely, based on my experiences, and a bit of conjecture: As compared to KT90 (taking KT88 as my reference... KT90 is a derivative of the KT88) - what I can offer is that every KT88 I've heard has vastly out-bassed every EL34 I've heard. EL34s are famous for mids, which they have in spades. I find them noticeably lighter in bass regions than KT88s. KT88 has great bass, good mids, and great highs - if anything, the KT88 is pretty well balanced in my experience, from low-to-high. The EL34 *is* an octal tube with similar operating requirements, so it's a drop-in replacement with many (but not all) amps that take KT88 and KT90, but it's not really a next-door neighbor of those tubes, soundwise.
I've not heard of 4FU29 tubes.
Based on your listening preference, you may indeed quite like the EL34s. They're *the* midrange tube for many listeners... but they give up some ground to KT88/KT90/6550 in the lower frequencies.
I've not heard of 4FU29 tubes.
Based on your listening preference, you may indeed quite like the EL34s. They're *the* midrange tube for many listeners... but they give up some ground to KT88/KT90/6550 in the lower frequencies.