Reviews - KST-150 Power Amplifier

Feedback - Customer Testimonials

I inferred from your web site that you are the main contact person concerning feedback response to the KST-150 amplifier. I purchased the amp from a dealer since my own assessment of the product is that it's absolutely fantastic. In fact, it is the best amplifier I have ever heard or had in my system and I have had many of the best possible amplifiers grace my system over the years from examples such as Audio Research D250, and most recently Halcro. It is most interesting because I feel the KST-150 outplays the Halcro by a country mile. While the Halcro has a lot of "information" and detail, the KST-150 has even more information and detail but delivers the sonic landscape with a considerably higher level of musicality.
The KST-150 is superbly musical easy going on the ears, incredibly natural, dynamic, open and capable of revealing the most subtle micro dynamic details present in every recording I listened to . I have literally been rediscovering my entire CD collection like never before, hearing things in a new light and hearing things I never heard before. I must say this amplifier took me by surprise since it looked so unattractive. I didn't play it for two weeks since the fit and finish suggested that this was conceived and manufactured by a fly by night small company in someone's basement. But then I occasioned to come by Dave Thomas's review in Stereotimes and this provided me the impetus to connect it to my system (Martin Logan Areius2's, CAT preamp, Sony SACD player). I was shocked. I hope you guys know that you have a monster on your hands and I am surprised that your KST-150 hasn't commanded a more prominent and deserved position in the industry.
There is no question, the KST-150 is the best amp I have ever heard and want to congratulate its designer for a superb job. By the way my staple of assorted equipment includes a B&K ST-140, and believes me the KST-150 beats the pants off the old B&K design. The ST-140 is nice and full and warm sounding, but lacks the resolution of the KST-150 big time. All of my audiophile friends have commented on the sound of your wonderful amplifier. Many are interested in buying it. Thank you for such a wonderful product.

Donald Pennington

Just received my Luminance KST 150 amp and I am truly amazed at the sound of this amp. I have owned many fine amps (I thought) in the past, i.e, Edge, Spectral, Krell, Audio Research, just to mention a few, but I have never heard a better sounding amp on my system, which consists of H-Cat 12PB preamp, Duntech Sovereign speakers. I am truly overwhelmed with this amp. I feel that I have been listening to mud for many years, but the Luminance is the most neutral, quickest and transparent amp that I have ever heard. Thank you for a wonderful amp. You have made this a wonderful Christmas present for me. My wife says that it is the best sound that I have ever had and she has been listening with me for 47 years.

Dennis Lockhart

I purchased a KST-150 from a private owner two weeks ago. Since I have had the amp in my system, it has sounded nothing less than incredibly fantastic. It beats the living sxxt out of my Levison No.336. Incredidibly fast and detailed sounding. What difference between KST-150 and B&K ST140! ST140 sounded warmish and comparatively rolled off, but musical. The KST-150 is very neutral with a ton of dynamic range and impact in the bass. The KST-150 is bargain, just like the ST-140. I am a member of the Florida Audio Society and would like to do a review of the KST-150 in our publication. Could I obtain your permission to write such a review?

Thomas Batnik

Just wanted to inform you that last weekend I brought my KST-150 to comparison shootout at an audiophile's house. The comparisons were all blind tests. No one knew or could see which amp was playing. The contenders were: Krell KSA-250, Halcro dm158, Convergent Audio Technology JL-2 and a Bryston 3B. Do you know which amp won the showdown? The Luminance by a unanimous margin. Everyone was shocked. I gave them your contact info and hopefully some listeners who are interested in your product will contact you. I continue to enjoy the KST-150 to no end.

Donald Pennington

Exactly two months ago to this day I purchased a KST-150 spurred from the rave review I read in Dagogo. Right out of the box the amp sounded horrible-brittle, thin, harsh, two dimensional etc. I decided to give it a chance by following the recommendation in the owner's manual suggesting a lengthy breaking period. Over the next ensuing weeks magic appeared before my ears. The sound is now utterly stunningly incredible: detail abounds everywhere throughout the frequency spectrum, wall to wall imaging, and bass extension at least another octave. Up until this point I was strictly tubes. My amplifier was the Audiopax 88, driving a par of Quad 57's.
The combination of the KST-150 and the Quads transcends all the limitations I previously thought were the speaker's limited frequency response in the bass region, but now using the KST-150 I have genuine bass authority with phenomenal control and definition emerging from an utterly transparent and open soundstage that recedes a good 40 feet into my neighbors house! I continue to marvel at the sound of this wonderful, wonderful amplifier and cast my vote that the KST-150 is the industry' best kept secret. I know that once audiophile listeners will find it hard not to disagree with my conclusions for I have been asked by several casual observers what large change I made in my system that could yield such an incredible improvement. When I point to the amp and disclose the price the expressions of disbelief fill their faces and suddenly I am bombarded with questions like "it's a solid state amp and it just can't do that" to which I respond "it can and it does".
Hats off to an astounding engineering achievement. I don't mean to gush, but here it is called for. I hate rave reviews. Here I am writing one. Wish you guys all the best in being successful. Doesn't worry about the cosmetics-just let the performance sell itself. My only quibble: the one year warranty should be extended to at LEAST three years, otherwise people my suspect reliability issues.

Bill Corbin

I must say we love this amp! When we were finally able to hook it up to different pairs of thoroughly broken-in speakers, we found it to be wonderfully transparent, fast, clear, and dynamically accurate on both small signals and large, even simultaneously. It is very, very musical and a marvelous value at its price. Its tone balance is just right, and the build quality is excellent. We challenged it in some very serious ways, and it stepped up to the plate every time, even to the critical ears of several experienced visitors. We highly commended this amp to anyone!

Roy Johnson - Green Mountain Audio

I just purchased a KST-150 yesterday. The dealer had the unit on display for one week and I noticed it when I went there to have my turntable aligned. I asked him for a little history about the company and the product and he said it was virtually unknown and very small. He advised me however that I take the unit home and audition and check it out away. I did and was absolutely astonished. WOW! I I never returned it and gave him asking price right away. Since I first acquired it, I haven't been able to move from listening chair.
Everything in my vocabulary of audiophile jargon has been obsolete by the performance of the KST-150. Terms like musical and detailed just don't cut it, even though the KST-150 is both those things in spades. I cannot describe in words what the KST-150 has done to my system. And therefore shall choose instead to say that for the first time I believe I am hearing for the first time an utterly neutral component. I have two systems. I have a vintage system consisting of Quad 57 speakers, Dynaco PAS3x preamp, Dynaco ST-70 amp, AR turntable, Sonus Blue cartridge.
The KST-150 blew the Dyna 70 out of the water and gave the quads some bass and top end. My other system is a pair of Vanstersteen speakers, Nuforce amplifier, CAT preamp and a Mission turntable with a Micro Benz cartridge. Once again the KST-150 made mincemeat out of my Nuforce, which cost 9k. The difference is not subtle. I can hear it in the next room. So can everyone else who has heard my system recently. I just felt compelled to write you because you are probably trying to get some notoriety, which not easy.

George T. Groom

I met you at Denver show, at which time you gave me your card and I just ran across it. I noticed amp in Dagogo review and bought one from xxx about three weeks ago. I considered the amp to be fully broken in because it sounded marvelous right from the very beginning. The KST-150 drives my Martin Logan's like no other amp ever has. Unlimited drive power and oodles of slam. Outstanding bass definition and control. The most remarkable aspect of the performance of the KST-150 is that I cannot get it to clip, ever. It sounds like it's got 1000 watts per channel under the hood. You didn't make a mistake on the power rating do you? Might want to check that.
I recently dragged out a pair of Dahlquist DQ-10's from the closet. These speakers were terribly inefficient and hard as hell to drive. The KST-150 handled them like a beagle on a choke collar. Again, no clipping. I consider it the most remarkable audio purchase I have ever made. Dave Thomas was right in his review. You could easily charge twice the money. I wouldn't complain give us some Cosmetics. In today's market, they are important.
I think the more I listen to it the more I like it. It never seems harsh or bright but always smooth and musical with lots and lots of detail. I was listening to Simon and Garfunkel's Bokkends album last night and on the track "save the life of my child" I heard a background voice I never heard before. It is moments like these which keep me coming back for more from this amp. I will call you soon.

Ken Little

I have for a variety of reasons had to postpone my promised appraisal of the Luminance Inspiration amplifier I have had entrenched in my system for the past six months. While the delay was not planned, I deem it a good thing. I have been a devoted/obsessed audiophile for 30 years, and I know too well that the path to perfection in this hobby is often littered with false positives -- the notion after too brief an audition that one has found the holy grail of components, followed by a disheartening realization of its faults/limitations after its full measure has been taken. We've all been there.
Having once owned a high end audio store, literally hundreds of pieces of audio gear have passed through my systems. These included top-of-the-line amps from Krell, BAT, Classe, VTL, and Jadis -- all very, very good. Each one, though it sounded glorious in some regards and on some program material, left me dissatisfied with other aspects of reproduction; and my disaffection would always begin with perceiving something bogus about the music that would leave me indifferent to listening, and then to putting on my analytical hat (which just kills the music) to ask, "what's wrong with this?" And so onto the next candidate, hope springing eternal.
After a couple of years of audiophile burnout, I succumbed again and began building a new system. I tried three amps before installing the big Luminance. Contrary to common sense, I bought this amp sound unheard, based on two things: Steve's pedigree as a circuit designer and your chassis design premise. Now that super-resolving circuits and loudspeakers have allowed us to hear pretty clearly the insidious effects of mechanical vibration (including the vibration caused by the flow of electricity itself) that attaches itself to, and pollutes, electrical signals, I am surprised that chassis construction has lagged so far behind circuit strategies. There certainly never has been anything like the Inspiration.
This amp ought truly to be an inspiration to the entire industry, so completely does it banish the effects of resonances that we've taken for granted as an unavoidable cost of reproducing the original event. Not any more. The brass chassis, with its ingenious system of channeling resonances out of the electrical circuit -- and away from the music -- is sensationally successful. The effect is unlike anything I've heard. In fact, I feel stronger about this six months in than I have at any point since the Inspiration showed up. It presents detail that is just thrilling, but never edgy or tiresome. The music blooms -- it billows -- like it does live. It's as if the gritty little amusical ripples that ALWAYS have been there, but which I haven't really been able to isolate until the Inspiration showed me their absence, are washed away. The music flows with a combination of liquidity and silkiness together with power and explosiveness that I've never gotten from an amp. The novel purity of the sound together with its resolution and sheer power is a first. Now that I've heard the difference, I can't imagine giving it up.
You stressed to me how "fast" the amp would sound. Yes, it does. Certainly. But that's not exactly how I like to think of it. "Fast" is a quality that I never associate with live music. For 19 seasons, I have leased a box for Dallas Symphony Orchestra performances at the Meyerson Center, one of the finest sounding concert halls in the world (just listen to the Reference Recordings titles of the Dallas Wind Symphony recorded there, or the older Dorians with Mata and the DSO for that matter). I have never thought to myself while listening to that glorious music, "this really sounds fast." It just flows with clarity and power. In the world of hi-fi, I hear people referring to stereo sound that is kind of threadbare and lacking in weight as "fast." I understand what they mean; when the treble transients preponderate over the lower regions, there is a sense of swiftness, partly, I think, because these systems de-emphasize the bass range in which so many rooms artificially elongate the tails of bass notes, and so make the music seem bogged down. But real music has weight and is dense with tonal color -- like this amp.
The Inspiration has strengthened an opinion I was beginning to form some time ago, and it's a bit removed from mainstream thinking. I have often seen it written and heard it said that source components are the most critical to sound quality. I used to accept that. But your amp has convinced me otherwise. I believe that the amplifier -- the component that creates the final electrical signal and drives the mechanical transducer -- is the most important. I would trade my sources and my speakers for items costing half as much before would trade the Inspiration for any other amp. I have indeed, replaced my source since installing the Inspiration, and I have, out of the curiosity created by the performance of this new amp, briefly put two other highly-touted amps into my system to compare. The difference was even greater than I had expected; I guess I had begun to take the enhanced performance for granted.
These are amps that I had once thought sounded very good; when I hooked the first one up, it sounded so inferior, I thought there was something wrong with it. The biggest difference wasn't the elucidation of detail; I could hear every little sound with each one. There were two differences that I could identify. The first was purity. The Inspiration just strips away that fine layer of grittiness that makes stereos sound canned. Second, music from this amp blooms. It's got that special kind of liquidity, sometimes associated with tube amps, which causes sounds to billow out and decay like they do live. With tube amps, though (and I've lived with great ones), one can almost get the impression that they are adding something to the signal which very closely approximates this kind of liquid fullness, but isn't quite the real thing. I also question whether I could achieve this kind of control over my woofers with even the best tube amp.
So that's it. This piece of gear has given me more musical satisfaction than anything I've owned. It's such a huge advance that I have two wishes for the audiophile community. The first is that you are able to get the word out, get the product reviewed, and focus attention on the hugely beneficial effects of the resonance reduction strategies you've applied to the Inspiration's chassis. I can only imagine how fine the sound would be if your resonance solutions were applied to every component in the chain. The second is that you are able to apply these techniques in a fashion that isn't so expensive to manufacture. This amp is absolutely beautiful; and one look inside reveals how you've spared no expense in design, materials, or construction. I'm betting you could get 70 or 80 percent there with a typically brilliant Steve Kaiser circuit sitting inside a less expensive, but similarly directed, chassis design.
Keep up the great work, and thank you for making this amp.

Mike McKool