KT150s in Audio Research Ref 110.

samzx12 OP
KT150s in Audio Research Ref 110.

The Ref110 was originally made by AR for 6550’s
I had an amp that I tried 6550’s, KT90’s KT120’s and KT150 in, it suited all.
But I found it sounded the very best using the Green Label plain white box mil spec GE 6550’s, this tube sounds way out in front of all the others for sound quality, btw the glass envelope was twice the thickness, you could tell when you ficked it with your finger nail, there was just a dead thud, instead of a ping!
Just like these > https://www.ebay.co.uk/itm/202717315969

Cheers George

Those are some expensive tubes.

samzx12 OP895 posts08-13-2019 11:37amThose are some expensive tubes

Do you want the best? they will sound better than anything else, been there done that, as I mentioned.

Cheers George

For several years I had auto-bias integrated and power amps and I went through all the power tubes (and several small pre tubes). I ran El34, kt77, kt120, kt150, Kt88, 6550. I kept coming back to the El34s and the 6550s. At the time I had a pair of Spendor sp2/3s that the Sovtek 6550s sounded wonderful with. The Sovteks were new production and reasonably priced. 

George I understand.  Sometimes you have to pay to play. Been there with a  few tube amps.  From my understanding ARC ran low on 6550 tubes and the later production runs of Ref 110s used the KT120s.