Do we still need 6550 or KT88 tubes?

I'm told the KT120 has a bigger bottle and won't fit in my ARC VT100, so I'll continue using 6550's unless I hear differently. Also use 6550's in my guitar amp.

I also agree with Wolf, at LEAST as far as musical amplification goes... headbangers will agree. (mental note to myself: switch your amps past standby)

Concur with positive comments about KT-120. Much more dynamic, open and great bass response. Never had a KT-120 blow accept when brand new, occasionally one or two arc'd and took out a bias resister. But that also happened with Winged "C" 6550s.

I have an Octave V110 (designed for the KT120) and I have to say in terms of tonality they are my least favorite. IMO I think they are too forward in the mids and bright in the highs. Nice and punchy in the bass though. If I put more laid back/warmer input and drivers tubes in they can sound pretty good. Give me an original Tung Sol 6550 solid black or grey plate any day. If the TS KT120 is too big check out the Ei KT90 type2. IMO again similar but better than the KT120 but also more pricey and a lot less than the TS solid black or grey plates. The big thing the KT120's have going for them is their price.

Sure would like to see some specs and prices for the KT150.

Has anyone seen or tried these KT120's from Shuguang?
http://www.leisure-audio.com/Shuguang-KT120-tube%EF%BC%88replacing-KT88%29-p186.html
Something new I guess. Although I would rather see a KT120 from the Psvane side of the business.

Oh to answer the original question I think we still need 6550's and KT88's for the amps that can only take those. Otherwise I think the KT120 will be the new standard mainly due to it's cost and reliability. It's rated for a max plate voltage of 800 where most amps are under 500V on the plate. The V110 is running at 620V for the KT120's (540V for EL24/6550/KT88's). So at a 450 - 500 plate voltage you can push the KT120's harder.

This is my opinion and so far I am the only one who doesn't care for the TS KT120 sound. Ok I may be spoiled with the TS 6550bp and gp.

OP-

Absolutely! we need different tubes, as, one will not fit every product.