This is a review of the Margules I-240 Class A Tube Integrated Amplifier (USD 7000). I’ll start by saying the obvious: we love tube amps, I mean, what’s not to like? The sound, the aesthetics, and the visual glow of tubes hypnotize. Much has been written about the warmness of these amplifiers, so I won’t delve into that sound characteristic, especially because this review is of a tube amp that does not comply with that storyline, no “warm-tube-feel” here. Yes, that’s a good thing. I’ll explain.

Started in 1927, and now a fourth-generation family business, Margules is perhaps Mexico’s best-known and well-respected audio company. Their speakers, amps, preamps, and now streamers, can be seen in many restaurants and bars in the south of Mexico. The brand (built, manufactured, and assembled almost entirely in Mexico) and design, is considered high quality and top-tier high-end sound. Not to mention they make different series in their product line of components, that are relatively affordable.

I’ve always lived in the north of Mexico, except for a brief period when I lived in Guadalajara (in the state of Jalisco); that was a long time ago, and it was during my stay that I got to listen for the first time to the Margules brand. Since Margules appeared in the late 1920s, they’ve made a mark. They appear at the most well-known audio expos (especially in the US) and always seem to surprise and leave the public in awe with their gear (a quick search for reviews of their products will suffice). Their designs seem very nature-based, with woods, curved lines, and dark metals that are quite unassuming—their minimalist colour selection captures the eye.

The Journey to Margules

I got word that Jacobo Margules (chief engineer and running the day-to-day operations of the company) had a small boutique shop in Guadalajara. Through social media, I was contacted by someone who knew him personally, so I decided to check it out. I was later told that I could meet with him. When I got there, all I saw was a nice-looking clothes boutique. For a second, I thought I was in the wrong place. But, at the back of the store, I heard people talking, and some funky techno music was playing. I then saw a room filled with Margules components, a very cool listening room with natural colours and sunlight filling the space.

There were several speaker models, their gorgeous TT-10 Turntable (it took all my willpower and the gaze of my wife not to purchase it), their integrated amps, preamps, and streamers. Jacobo talked to me for hours, he commented on the “zero negative feedback and the ‘ANA’ technology” (more on this later) of the I-240 integrated. He commented at length about how the I-240 and its technology were in part based on their prior model (and big brother) the U280ASB amplifier. We talked about some history of the Margules company and some engineering specs. It was a great day to listen to fine music with top-of-the-line gear. I don’t even remember telling him that I reviewed products I was so immersed in this audio-nerd world.

The following day, after the accustomed (and dreaded) “talk” with my wife about how we needed this specific component for our home, we decided to purchase the Margules I-240 amp. I got this amp almost two years ago, and just now that I’ve been comparing it to other valve amps and solid state, I can safely say I can understand its sound and performance, what it can, and cannot do, what music genres are a better fit with it and which don’t. I laugh when I see people on YouTube review an audio product when they’ve had a week or two, that just seems impossible to me. But anyway, let's continue.

Nothing like a beautiful tube corona. Photo credit: Jesús González-Monreal

Specifications

Amplifier: Class A

Weight: 53 lbs.

25 Watts per channel at 8 Ohms

Frequency Response: -3dB 10Hz - 40 KHz

Total Harmonic Distortion: 0.15% at 1 Watt & 0.7% at full power

Bandwidth: 30Hz - 30KHz

Supply voltage: 120 VAC

Electrical Consumption in Stand-by mode: 145 Watts

Maximum consumption: 350 Watts

Dimensions: 7.50” (H), 15.75” (W), 15” (D)

Tubes:

4 x EL34 (6L6, KT66, KT77, 6CA7) & 4 x 12AU7 (pre-amp stage)

Design

The I-240 has a three-line level for RCA inputs and comes with the coolest remote control I’ve seen for an amp; it's made of wood with laser-like branded Margules logo—old-school meets new-tech stuff. Margules decided to go with no XLR connectivity; perhaps this goes well with their plug-and-play philosophy. I was fine with no balanced inputs, but what I did miss was a phono stage and, if I’m feeling a bit greedy, a headphone amp. Many integrated amplifiers today have many more options than this integrated, that’s for sure, and for the price tag, we might be remiss if we don’t mention that it lacks functionality for the present-day integrated market. But there’s something to say about separates (components) as well, and that is that they’re unique in their task, and because of this, many times, their sound tone or colour is very specific and elevates their performance and value.

The Margules integrated is quite the looker. The blue Margules logo at the center surrounded by eight tubes was a nice touch, the lights that reflect on my ceiling are an even better one; an elegant and sophisticated style. The right knob, smooth and comfortable to the touch, is the volume, and the left one is a push ON/OFF and input knob; two knobs are all you need. The amplifier comes in a beautiful blue silk cover sheet with the Margules logo and the best well-packaged component I’ve seen. You could throw the box from a second-floor balcony, and I would feel bad for the floor (it’s 53 lbs).

How it Sounds

The I-240 was tested with two very different speakers, and I would say that part of the magic of this amp is that in these comparisons regardless of their cost, it shined with both of them. The Alta Audio 4 ohm & 87 dB Alyssa speakers ($5000 MSRP) in my main system were superbly driven, and a full and immersive wall of sound filled my room. The Alyssa’s are always subtle, but paired with this amp, they presented themselves with subtlety and resonance. The other speakers were the Galion TS Voyager TL 8 ohm & 84 dB ($1195—review forthcoming). With these, the bass response was a nice surprise—the Galion just shined. You would think that 25 watts would not hold up with certain types of music with an 8-ohm load, but I was wrong. The Margules never skipped a beat with the music I listened to, in attentive listening or turning up the volume, it was constant, driven to perform.

There’s a very defined sound to this Margules integrated, and that is a 3-dimensional translucence, giving a fluid characteristic to my music, especially while listening to vinyl (Mark Levinson 5105 Turntable and PS Audio Stellar Phono Preamplifier) and SACDs (with the PS Audio PerfectWave Transport). There is no warm-tone experience of a tube amp here, but its soundstage more than gives the music a cohesive and full vitality. The 25-watt rating seemed low when listening to some of my dynamic SACDs.

Comes with an excellent remote control. Photo credit: Jesús González-Monreal

When I changed my setup to have other tube amps (like the Decware Zen Triode SE84UF02), the PS Audio Stellar Strata Integrated (solid-state), or even a hybrid, the Vincent SV-500 Integrated, the Margules sound would have a softer sound and pure presentation, that is, not a warm or cold or neutral sound, but with fuller and complete dynamics.

I also compared it to another amp that I just unboxed. The Starkrimson Duo/Trio amp (with gallium nitride GaN technology) from Orchard Audio ($1800), and I’ll have more to say about this amp when I have some time with it, but the initial sound of it is at the opposite side of the Margules. The I-240 sets itself apart in its “simple” tone and soundstage. There seemed to be a flawlessly delivered picture of each instrument that came with a solid and cohesive foundation of sound.

While we were talking about which speakers would fit better with the I-240, Jacobo mentioned something regarding the output impedance. Not wanting to change his description of the I-240, I decided to make a note of it and then went to their site. Margules comments: To improve the damping factor without resorting to negative feedback, Margules has developed the BEFS (Back Electromotive Force Sensor) system, which changes the amplifier’s output impedance upon load requirement.

Lastly, an engaging aspect of this amp surprised me. There’s more than meets the eye with the tone colour in this integrated, and perhaps this has something to do with some technology that Margules describes (very little of it on their site) called “ANA,” which stands for Acoustic Neurologic Alignment:

Focuses on how we as humans process and perceive sound, priori sing the harmonic structure over the fundamental tone (…) This technological advance has its origin in the theory of seductive sound (engaging sound) our brain decodes information from sound waves through the ears: when the sounds are close, they keep us attentive due to the relationship that exists between the perception of these, the distance in which we perceive them and their intelligibility. Distant sounds, even when they are intelligible, do not attract our attention and are easily ignored.

Something interesting about the I-240 is that it doesn’t require any polarization adjustment as you usually find with many tube amps, thanks to their Active Servo Bias tech. From their site: (the I-240) incorporates our exclusive Active Servo Bias (patent pending), which guarantees an optimal operation since it does not require any polarization adjustment, always operating at pure Class-A to ensure a detailed sound scenario. By continuously adjusting the polarization based on the signal, this circuit radically extends the useful life of the output tubes and allows them ideal operation, which in addition optimizes energy consumption and avoids overheating.

Music

The I-240 shines in electronic music. There’s something about this music genre and its recordings, that I’ve always had issues with tube amps; I just “don’t feel it’”—the silk-like tone and soft dynamics don’t blend with the thump-thump sound. Now, in jazz and rock, even classical recordings, that’s another story, the tubes glow and show finesse. But, the I-240 in these months has allowed me to explore that fluidity and rhythm feel in the electronic genre, that tends to clash with tube amps. Some of the tracks that filled my room were Masayoshi Fujita’s Migratory vinyl album (2024) which encapsulates solitude and a sense of wonder magnificently evoked in the Margules a constant: highs and lows, dynamics and response whole. While Kruder & Dorfmesiter adorned the space, the I-240 captured that bass dynamics as well as any solid-state amp I own. For a live recording I put on Gilad Hekselman’s vinyl Life at the Village Vanguard (2025) and the jazz guitarist’s talent shined once again in my living room.

Conclusion

There are certain things about the I-240 that I wish could be different. For one thing, it could have a wider sound characteristic, it’s centred and pristine yes, but this is where I believe the 25 watts have their limit; it isn’t that volume and intensity lack, it’s more the limitations of a more expansive soundstage. There’s no phono stage, only RCA connections, and for purists, the additional dBs from XLR are not present. Not including digital inputs will drive away some audiophiles. However, Margules set out to create a very high-end, pure-sounding amp, as well as a beautiful component, and that’s what they delivered: they set their sights on sound.

The Margules I-240 at USD 7000 has to make a Sisyphean climb in the mountain of integrated amplifiers today. I would invite you to look for Margules at audio expos or go to your audio dealer and ask to listen to one. If you do this, I can imagine that the decision to pull the trigger will be easier. It was for me. This is a marvellous and beautiful integrated amplifier and is highly recommended.

Further information: Margules