6550 and KT88 differences?

In a Cayin 70T, the general differences between the two boiled down to dynamics. The (EH) KT88s were fast and detailed and so they had great dynamics. The (SED) 6550s had a meatier tone, softer top end, and focused more on microdynamics than anything else. They were quite different but both good.

Arthur

Did one have a clearer midrange?

In my Prologue 5 (W/Prologue 3) the SED KT88's have an emphasis in upper bass and a more forward midrange, smooth and extended highs. The SED 6550's had a more linear response with a slightly soft high end and a tight but not bloated bottome end. Tonally the 6550's sound more coolish in the mid range. I preferred the KT88's. The SED has a lot of color that can be attractive, but......

In a Cayin A100T (and 2 other tube amps I have) the two types have a similar sonic signature, but I much prefer the 6550. In it the KT88's bass was a bit much.

I'm guessing that the Dialogue might sound best with the KT88's, but much will depend on the brand of KT88 - they can sound quite different.

Any suggestions on a KT88 brand that's still smooth and extended yet maybe a tad less colored than the SED? Seems like I've heard mixed things about the EHs.