KT120 transformer failures

Hey Wolf

I can't help you answer your query but maybe the gents over at Conrad-Johnson can. The CJ Classic Sixty SE Amplifier utilizes KT120 tubes throughout. Maybe they saw the current draw issue you speak of and overcame it. From stuff I've read about them they are really good people over there and who knows they may be willing to chat with you about the KT120 transformer issues.

Info about the Classic Sixty SE.

http://www.conradjohnson.com/It_just_sounds_right/Classicsixtyse.html

Luckily there seem to be NO transformer issues with the 502P. Not yet anyway, and I assume if it was gonna die it would show some signs of impending failure. My trusty warranty is there just in case. The CJ "SE" is on a price level that begs comparison to "things that interest me" like the Cary 120SII, Audio Research VS 115 (now with 8 KT120s!) McIntosh MC275, and other stuff, but the Jolida sounds so damn good and provides me with the requisite space heater and tube glow features that apparently I now need, so I'm content with it. At around a grand new there's not a lot out there that compares.

The newer ARC products have been designed with higher current ratings on the filament winding expressly for the purpose of using the KT-120. A few earlier ARC pieces, by virtue of their robust filament windings can also take advantage of the KT-120's. There are other ARC amps that can never use this tube do to issues where the length of the tube creates issues, i.e. cover will not go on or transformer in the way.

There's just nothing wrong with robust filament winding. I'm all for it.

Hifigeek, Have you or has ARC (to your knowledge) re-tubed a pair of Classic 120's with the KT120 without modding the tranny. 120's with 120's that should be a match in heaven.
However we're talking 8 output tubes per amp and that could put a major load on the transformer. Could we have a complete meltdown of the transformer. Would this affect the 6FQ7 driving those tubes.
Space is not an issue with mine as i operate them without the cages on.

In all honesty, although those have been modded by Steve Huntley in 2005, i think i would get a better bang for the buck (sonically speaking) if i replace those with a REF150. I need to get a "loaner" from a dealer and do an A/B comparison in my system. A 150 would likely pair better with my REF3 LE and REF2 Phono and Verity Parsifal speakers than the 120's.
Have been an ARC fan for 25 years and have had the 120's for 22 years, replacing a CL60. Analog front end? Well, too many to count. If i had kept them all, my house would have turned into an ARC Museum.