kt77 vrs kt120 in Rogue M180s


I recently was a able to compare gold lion kt 77s verses tung sol kt120s in my Rogue audio M180 mono-blocks, and wanted to share my experiences with you. I did these comparisons over a period of weeks, so I think I now have a pretty good understanding of their sound in my amps. The kt77s have a little bit more air and extension in the treble, nice midrange, and very good depth, and slightly looser on the bass. The kt 120s, were clear and very open sounding, with better projection into the room with the sound stage, with less depth than the kt77, but have better width and separation. The kt120s also had better Bass extension and control over my Revel f32s woofers, They seemed to wake up the speaker, everything sounded dynamic and full. Besides the little bit of roll off in the highs, I much preferred the kt 120s in my system. Hope this helps some of you, Christopher
chrissain
Jedinite24 and Samzx12,
It was probably EH/New Sensor's fault. I think it was about 2-3 years ago when my audio dealer started complaining about a VERY bad run of EH KT88. They experienced an extremely high (early) failure rate of these tubes in that time period. Not sure if they've fully resolved those quality issues. The EH KT90 was far more reliable, even though I actually had one of those blow up (at low hours) in my amp. The KT120 have been very solid thus far.
The EH KT88s Rogue was getting had some quality issues. I don't think Samzx12's trouble with them was rare. That prompted Mark to go with EH KT90s as the base offering. It was simply related to the quality issues with the EH KT88s.

My GL KT88s were a $320 upgrade when I placed the original order. I've had no trouble with them.
I knew someone would ask that question lol. I should have noted when I bought my Tempest it came with 2 sets of KT88's and the seller didn't know how old they were. He didn't think one set was that old but I blew 2 tubes and the bias was set dead on. I even rechecked it several times to make sure it didn't wonder. I finally said screw it and bought a matched quad from Rogue.
Tube failure just seems inexcusable to me. I have had tubes in guitar and bass amps that suffer insane abuse relative to our pampered hifi stuff (tube "combo" guitar amps have the speaker and amp in the same exact acoustic space) with 1 tube explosion over 40 years of use. That was in my Magnatone combo in 1968. I sold it shortly thereafter for a 61 Bandmaster (my cousin's amp...he bought it new and I used it on and off until 1986). I suppose a few lazy people on the Volga New Sensor assembly line are to blame, and I assume they were shipped off to Siberia or Brockton.