Review: Kora Electronics Kora Explorer 150 SB Tube amp

Category: Amplifiers

My local dealer sells Kora so I get to hear a lot of their gear. One day I was in the store when I found an Explorer 90 for sale. I bought it on the basis that my favorite audio reviewer gave it top honors (Diapason d'Or 1999). It is indeed excellent and so when my dealer got a 150 SB, I wanted to give it a listen as well.

I listen to all kinds of music, particularly acoustic, alternative and electronic. I don't have any neighbors in sight so I get to listen very loudly. I have had the 150SB for about a week and it was already fully burned in thanks to Michael Fremer at Stereophile Magazine who sent his (second) review sample to my dealer. Speaking of his review, many have felt it was quite negative but reading it carefully will reveal how only the ergonomics were at fault - and I do agree they aren't the best.

However the sound is sublime and this is what I want to point out in my review. It is much more detailed than the 90 and its dynamics and high frequency extension are much improved as a result. It has just the right amount of coherence to keep the soundstage together and the details in check - something my Mc/BAT can't always do with the Prima as the source. The 150 doesn't have quite the resolution of my separates, nor the last bit of bass control, but that doesn't matter really since beautiful music comes from the speakers. I am very impressed with this amp and for the money, it is about the best thing going.

In conclusion, I would like to say that this amp will do best with a detailed source and transparent speakers. High sensitivity is not recommended as it does have a moderately high background noise level but somehow that never seems to interfere with the impressive clarity it delivers. It has plenty of power for my small room and never got compressed even at very high levels.

The Kora 150SB is very highly recommended at its price point. I wasn't expecting such a beautiful sounding amp.

Associated gear
Click to view my Virtual System
Funny enough, I had another 150SB integrated in my system last week. My thoughts still hold - it is amazingly good. However we put it in my local audio buddy's system and it didn't sound that good - too much bass which made the mids sound thin and recessed. But I am basically certain it was a room problem as his room/speaker combo excites room modes easily. Back in my system, the 150SB was awesome.

Interesting thing about Kora is that all their gear does something in common: They reveal the style, mood and feel of each track of each recording. Fast music sounds fast and punchy. Slow music sounds slow and delicate. People's accents come through loud and clear. Dark music is heavy, thick and melancholy. Happy music is fun, light and exciting.

So often you hear that Amp X is good for jazz and Amp Y is good for electronic. However the Koras aren't that way because they are so transparent and neutral that what is on the recording is what comes through. I think this is a trait that all top notch audio equipment should have but in many cases, you have to spend way more money to get it. This is what makes Kora so special to me.
I have heard many good things about Kora amps, but I have also heard that it is very difficult to bias the tubes, and that it needs to be done by a dealer- any comments from owners?
The tube biasing doesn't apply to the 150SB - only the full tube amps like the Cosmos and Galaxy. But it is simple to bias them if you are patient. All it takes is a little time.
Can you help me guys ? I need a service in New York City . I have a pair of Kora Cosmos and I have a problem ! The problem is one tube it`s to light . Something wrong but I don`t know what ? So please help me somebody thank you.