Lab12 Integre 4 MKII - user review

I admit my experience with tube amplifiers were rather limited. I’ve heard a flagship Line Magnetic. I’ve heard Lab12 Pre and Suara when auditioning the DAC1 Reference. They sounded good but I didn’t feel that they drew me in enough to immediately want them. But sometimes later I’ve heard the Jadis I70 paired with Gryphon EOS2 in a show, and I fell in love with it. The “live” feel of it was amazing and I had so much fun listening to that setup. I preferred it to the much more expensive Borresen 05 paired with Aavik Class A integrated exhibited in the same show.


I began to consider Integre 4 MKII, a KT170 based integrated just like the Jadis I70. Home auditioned it for one week and decided to purchase it. Here’s my honest take on it after living it for another couple of weeks.


I know that the main arguments against having a tube amp are the heavy weight, constant biasing, and the heat. I’m not sure about the heat part because my previous amp is a Sony TA-A1ES, a high bias class A integrated, so I was kind of used to a hot amp. Though it did noticeably run hotter, but I found it still acceptable to use it for a while without turning on the AC despite living in a tropical climate.

I am not sure what dark magic Lab12 practiced, but the Integre 4 MKII is undoubtedly the lightest and the most compact of all the KT170 amps. It weighs only 22 kg. I70 weights backbreaking 45 kg and all the others on the market like Cayin’s weigh above 35 kg. It was easy to place the Integre on my rack. It is also very easy on the eye. I showed my wife photos of popular tube amps and she thought Lab12 looked the best, Qualiton came close though.


I Youtubed videos of how to bias some of the popular tube amps and yeah, didn’t look like the most fun thing to do. With the Lab12, the biasing process was painless. With the LED screen, it took me approximately 5 minutes to bias all the KT170 tubes. ARC did it first with their VSI75 integrated, but Lab12’s take on this is simply superior with the screw pots on the LED panel itself.


How does it sound then? To be honest my first reaction to it was mixed and I didn’t fully fall in love with it immediately the first time. The demo set I tested used KT150s instead of KT170s. One thing that hit me immediately was the realism of acoustic instruments. I am a full-time trained pianist and for the first time my setup could reproduce piano recordings very precisely. Resolution and detail retrieval were an upgrade; I could make out smaller details more easily now like the sounds of pianist’s feet changing the pedals. The bass quality of this amp was far superior to my previous amp. There was so much more ‘meat’ to it; cello and double bass sounded so much more convincing. The dynamics and PRAT of this amp are marvelous. My previous amp would strain when reproducing loud and complex music, but the Lab12 could handle those without breaking a sweat with still plenty of headroom. Kick drums and timpani had the punch that was missing from my previous Sony. The amp truly exceled in drawing you in and placing you in the center of performance; every music felt ‘live’ when listened through it. Loved it.


But there were caveats. With my previous Sony amp, the holographic effect and soundstage were cavernous, almost like wearing a giant headphone. With the Integre, the sound was still holographic, but it was noticeably narrower, and the sound was more centered. The bass quality though was good but there was less of it. Gaming and movies experience were not as good; I missed the cinematic feel my Sony amp provided. The sound was also more fatiguing, I found that the maximum I could listen to music on the Lab12 was around one hour, less than that if I was listening to rock or loud orchestral music.


It was not an instant buy for me. The dealer listened to my feedback and loaned me a pair of Black Cat interconnects. With the Black Cat, the aggressiveness seemed to be toned down and there was a smoother softer edge, though this came at slight loss of dynamics and realism. It was an easier sound to live with. I decided to take the plunge as it seemed like most of my concerns could be alleviated by experimenting with cabling.


My new set obviously came with KT170s. So, what changed moving from KT150s to KT170s? The sound I described above remained largely the same, but there was a softer edge to the sound that makes it more pleasant. With the KT170s the sound was now only borderline fatiguing and I much preferred that. The soundstage was also wider and there was greater depth. Not as wide as my Sony, but wide enough for me to accept the slight compromise. With KT150s the Integre is a very good amp, with KT170s I do think it’s one of the best sounding integrated monies can buy. I’ve heard more expensive amps in the five digits range from the usual suspects like Esoteric, Luxman, Aavik, AudioNote, Accuphase, Naim and I can confidently say Integre 4 MKII outperforms most of them. Was it as good as the Jadis I70? I did not have a chance to compare these two, but with my setup I think the SQ was identical to the setup I’ve heard with the Gryphon. Does not matter though, the price, weight, and QOL are simply better with the Lab12 Integre 4 MKII. It’s a stunning piece of hardware and IMO is good enough to be an end game amp regardless of your budget.



Very realistic timbre

Highly detailed 

Very quiet

Great dynamics

No shortage of PRAT

Lightest in its class

Very easy to bias

Runs reasonably cool

High WAF factor

Competitive price

Good holographic feel and wide soundstage



Borderline fatiguing

Not for bassheads

Soundstage could still be wider

Gear matching needs care

No pre out/sub out

No bi-wiring



Cabasse Riga

Cabasse Mercure Sub

Lab12 DAC1 Reference



Soundstring Gen1 XLR

Soundstring Gen1 Tricormaxial

Nanotec Golden Strada Sp#79 MKII
Oyaide Class S USB Cable

Furutech Roxy (Amp power cord)

Real Cable Citrine (DAC power cord)

Supra Lorad 2.5 Anniversary (PC power cord)


Rack: Quadraspire Q4 Evo



Nice review one question you say this tube IA can be fatiguing, maybe KT120s would be the ticket and is the room treated?  Just have to ask. I have never listened to a tube IA that was fatuiging ever. I have found the KT170s to have more headroom and mid bass more pronounced. 

Great choice though I am partial to Octave and Ayon. 

An update. Since I wrote this review, I have upgraded my speakers to a pair of Baltics. The cablings and cords have also been upgraded with a decent premium selection worth around 5000 usd.

Interestingly, I also acquired an additional pair of Baltics for my workplace that I drive with a Perreaux DP32 and 100P stack. Cabling more or less similar in quality and price with my Lab12 setup. While not at an exact price point compared to the Lab12 stack, it provides a good comparison between a good SS solution and the Lab12 stack.

Long story short, the Lab12 has a higher performance ceiling compared to the Perreaux. The tonality, realism, and PRAT are jaw dropping. BUT it took a not insignificant investment and careful matching of cabling and cord to reach that point before the magic happened. With cheaper cabling the soundstage was modest and tone was rather aggressive. 

The Perreaux stack had been around for one decade now. Even with cheap cabling it was immediately more likable with its bigger, smoother and relaxed sound. Zero fatigue. With more exquisite cabling, the level of performance came close to the Lab12 stack. Very enjoyable presentation but the realism could not match Lab12. 

@nainghsy Woah, Lab12 stack for Rubicon 2? I’m sure it would sound great. I do not know how Rubicon 2 sound but I auditioned Opticon 2 and I do think they would love tubes. But like I mentioned above you might need to prepare set aside a sizeable budget for cabling. Perhaps consider the Perreaux stack. You could probably find it cheaper used or ex demo. And on the plus side it runs much cooler. 

@audio_is_subjective  I've heard the Lab12 initially at the dealer's showroom they were driving QLN Prestige 3. Yes, even in that setting there was an edge to the sound. My room is treated with acoustic panels to help tame the highs, but it's the choice of cabling in the end that refined the sound (I am using Ricable Invictus Reference speaker cable and power cord for the Integre).

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@auroravengeance can I consider getting Perreaux stack an upgrade? Currently, I'm using Anthem MRX 540 AVR (ESS ES9010K2M Sabre DAC). Your input is much appreciated.