Kt120 Vs kt90 Sound characteristics

Have the kt90's and would someone clue me in on sound differences on the 120's not power isnt important


The 90's came with the amps.

I used Gold lion kt88's sound great Smooth great mids, but the Bass is not even and the highs are attenuated somewhat, going back the the Kt90's was a god send.

Wondering if the Kt120 is more refined or just more forward ect.

Have you considered contacting rogue to ask them what the sonic profiles would be on those two tubes? I have a PrimaLuna Integrated and use KT 150 power tubes. I did try KT 120s and found them to be too clinical for my taste

If you wish for good bass, smooth highs and a rich midrange, try KT77s. I auditioned the Cronus Magnum 3 at home with the stock KT120 and found them a bit clinical also. So I ordered the amp with Gold Lion KT77s installed from Rogue. If you choose KT77s you’ll need to reduce the bias from 35 to 30 as per Rogue.

The KT 120 tubes in the Cronus Magnum gave an authoritative sound but there was always a bit of grain in the background which I did not get with EL34’s. At the time, only Tung Sol made the KT120  tubes but there may be other manufacturers now.  I didn’t care for them.  I sold the amp after a year and a half as it wasn’t what I thought it would be.  I was disappointed.  I wanted a more lush midrange with better bass and no grain. 

@stereo5 I’m an ex EL34 diehard myself. Over time learned Tung Sol KT120s can sound really good with at least two factors present. Lesson learned here before making premature judgement. Burn-em in at least 200+ hours, no joke. They DO settle in nicely, same with my KT150s changed at 300hrs. I learned this from Conrad Johnson owners too. Today I run KT120s today in my mono amps. The second is a game changer for digital front-ends. Making sure a really good digital source/dac is used along with a clean and quiet power supply. I like the sound better than my former EL34 amps now. As for KT90s, I won’t digress, there are several reviews indicating few amps run KT90s well, and most moved on to KT120s anyhow. My KT150s sit in their boxes. KT120s can sound good, given a fair chance in well designed amplifiers, good transformers, caps, bits inside.  


I get what you are saying but I used that integrated with the KT120’s for over a year at 8 hours a day.  Surely the tubes would have been very well broken in.  Perhaps it was the Rogue Integrated itself that was introducing the noise.  It was the first gen of the Cronus Magnum that I bought used.  Maybe the second and third generation was better?

Which KT90, the Electro Harmonix? In the Rogue tube amps, EH KT90 has more treble energy while being leaner through the midrange and bass compared to Tung-Sol KT120. I think almost everyone prefers the KT120, unless you have a particularly dark system that needs the extra zing up top. 

KT120 have excellent warmth, body, and bass impact. Great for rock. They have a bit of "sweetness" to them, but not as much as you'd expect from say EL34. You may or may not find preference with Gold Lion KT88, which have extra airiness and refinement to them, and slightly sweeter midrange, compared to KT120. 

@stereo5 Maybe the second and third generation was better?

A short reply of yes, maybe.  Not totally sure but doing some quick research, if yours is the first generation, looking back found some audiocircle posts with members in 2013 liking the later Tempest amp with KT120s better compared to the early Chronos, sounding "strident". iirc, reading about this a few years ago -  there were  design and component improvements with the gen II, III, also noted several trying different 12au7, 12ax7 tubes in Chronos hoping to achieve a more lush sound.  I wonder if you call Rogue next week and ask if they could offer a means to upgrade yours to the later versions somehow.

Might be a worthwhile inquiry. Best of Luck.    


I tried a bunch of different signal tubes including NOS Mullard CV4003 tubes and some other exotic tubes.  Although it did change the flavor, that grain was always evident.  Unfortunately, I sold the amp when I bought a McIntosh MA6600 integrated which I use daily in my office system.  Next up will be to get a pair of Cornwall IV’s to try in the office system.  I’m currently using the new JBL 100 Century speakers in the office system with a single SVS sub.  While I love the sound, I have an itch to try the Cornwalls.  I use that system to try different speakers. 

Jbl l 100 great The cornwall will have added presence with that compression driver.

 both companies have been around for a while, post your findings

Thanks for the post