KR Audio KT88 Vacuum Tubes


Does anyone have experience with these power tubes?  I understand they are well made and likely last longer than their Russia or Chinese counterparts.  But, they are much more expensive.  My real question has to do with the KR Tubes sound quality.  Would you replace good sounding Gold Lion KT88s with the KR Audio tubes for a sound quality benefit?  I've also read they make the similarly expensive EAT brand tubes that some prefer.

coppy777

My amplifier is a Conrad Johnson ART27a class A producing 36wpc.  For the benefit of the first three respondents who have not heard the KR tubes, the amplifier lists for $22K.  The pre-amp is C-J's ART88 at $28K.  All pretty high end sound producers.

My interconnects cost several times what a set of the KR's would run and the speaker cables sell of about what the amplifier does.  So I'm willing to spend $1300 for a set of four if they truly sound better than the Gold Lions. I just re-tubed the amp's KT88s after about two years of use for about $400.  I buy tubes from reputable sellers or C-J, never on Amazon or eBay where the lower quality tubes end up.  I'm told New Sensor separates out their best testing tubes and they become the Gold Lions.  

As for the Sophia Electrics, I understand they don't manufacture their own tubes either, they come from Shantung in China.  But they are again some of the better testing valves from that company.  Rather the Gold Lions of Shantung and pretty also.

Thanks to trivema and retiredfarmer, thanks for your input; very helpful.  Tubes are a maintenance issue, especially in a circuit like this one which drives them hard to produce that much class A sound. At worst case the KR Audio tubes will likely last longer and the current Gold Lions will become backup for the next replacement cycle.

Still, don't need power tubes right now... unless they really sound better.

I am one of the dealers for KR and have had them in my own Art Audio Opus 4s. They have the same power output as a typical KT88 but the plate dissipation of a KT120.  They will last longer.  This is the same recipe KR used on their 300Bs.  Plate dissipation is 50w vs. standard Western Electric Spec of 40w.  

In practice, they are more linear. "Better" top end and tighter bottom end.  This means tighter bass response but also means a brighter presentation which is why better is in quotes.  In my system I found them to be too bright and shifted to a different tube compliment.  My amps also accept KT120s and I opted for those to get just the right tonal balance I was looking for.  If you are looking for more top end energy and tighter bass, they are incredible.  If you are happy with the Gold Lions tonal profile, move on.  

@verdantaudio , as a dealer, perhaps you can answer a question on where they’re manufactured? 
 

This Moon Audio listing claims made in the USA which could help some justify their higher price. However, I thought KR was based in Czechoslovakia and their tubes manufactured in Russia.

“Made in the USA, these tubes stand out for their superior performance and reliability, making them a valuable addition to any high-fidelity audio system.”

VerdantAudio... just looked at your site. Very impressive offering. And thank you for the perfect answer. Which begs the question... Other than blue, how is the SQ of the Sophia Electric KT88s vs the Gold Lion.

Moon Audio folks are nice folks and honest. If made in the USA is on their site it’s an honest error on their part. Czechoslovakia is correct for KR. Still higher cost for manufacturing than Russia and they are likely a much smaller company.