Acoustic Invader Fulcrum – End Game Preamp From Serbia

Fulcrum is a premium line preamplifier of a small Serbian brand Acoustic Invader. My previous contact with the brand was through its classic preamp reviewed here. I loved it, I raved about it, I purchased it, and I kept it in my system. However, today we’re talking about a model that is four times the price. Can it be an equally good value and is it worth your consideration? Let’s find out.

Build and Connectivity

Acoustic Invader Fulcrum uses an all-metal build. The front panel is especially thick and beautifully machined aluminium. The same thing goes for the input selector and volume knob that are milled out of solid pieces of aluminium. It sure looks and feels very premium when you operate it. The volume knob is motorized and without a volume pointer – so you don’t know if it’s at 9 or 11 o’clock for example. This was a deliberate, symmetry-driven, styling choice. That annoyed me slightly at first but I got used to it quicker than expected. I just crank the volume as far as I need and don’t care about where the volume dot would be at.

A remote control is provided and it is a metal slab that has the same luxurious feel as the main unit. I love its hefty feel and its aesthetics – it uses quality. I’m only slightly off-put by its very sharp edges. While it doesn’t bother me in use, I tend to lower it on my coffee table more carefully than usual so it doesn’t scratch the tabletop. I also remove it out of sight when friends with small kids are visiting. On a positive note – you’re always in a position of a cold weapon if you ever need one to deter a burglar.

Moving to the back of the unit, we can see all the inputs. All of them are analog, no digital inputs here. Three out of five come in both balanced or single-ended choices. The output can also be either single-ended RCA or balanced XLR. One interesting thing to notice here is that XLR connectors are sourced from Neutrik and RCA connectors are low-mass ones from WBT – which are probably the best in the business, in my opinion. Similarly, the IEC inlet is sourced from IeGo, with gold-plated copper conductors. All of these are usually used as aftermarket upgrades and are not commonly found in mass-produced products.

The Inside

I don’t tend to pay much attention to the topology and technical solutions used. The final results concern me more. So I’ll be brief here and mention a few basic things about the design, and a few details that caught my attention. The preamp is based on J-FET transistors that are, as I understand it, working in class-A mode. This should bring a pleasant sound signature that reminds one of a good tube preamp while preserving the speed, dynamics, and detail retrieval of solid-state preamps.

This design is supported by a no-compromise approach. For example, there are three independent linear power supplies inside. Two are used for powering each channel, and a third one to power the rest of the electronics like volume motor, input selector, and signal LEDs. All transformers, capacitors, and other parts used in these power supplies are of a very high quality.

Great attention is given to the signal path of course. It starts from those high-quality connectors on the back and continues with Duelund wiring to the main board. A highly regarded TKD potentiometer is chosen to control the attenuation. Rike Audio S-Cap 2 aluminium foil capacitors are used in the output stage. Once again, most of these internal parts are usually seen as aftermarket parts for extreme custom upgrades.

If you are in the camp that believes all parts sound the same if they are of the correct value – then all of this might feel like a load of BS. That’s fine and I won’t try to change your mind. I’ll just say that everything going into a hi-fi device has an audible impact on its final sound if the system is good enough and you care enough to listen for it.

Sound

Acoustic Invader Fulcrum is not one of these linear, wire with gain, kind of preamps. It has character, and it has many qualities alongside it. Starting with the tonal character first – this is a warm-sounding preamp. This is especially true if we’re talking about the bassline. There’s a distinct boldness and weight of bass with Fulcrum that gives a thick and bold sound to all of your music. It’s not overcooked though, and most importantly, I never feel it’s sacrificing resolution to achieve that. The bassline is agile, it moves with grace and can reveal inner tone texture very nicely. I listen to my favorite double bassist Nenad Vasilic and his strings are recreated with admirable weight, yet filled with fine details.

Move to the midrange and there is still a trace of that boldness and warmth giving vocals a beautifully present and natural appearance. The same goes for wind instruments that, just like vocals, sound lush at all times. This lushness never translates to muddiness. Overall transparency and resolution stay very high at all times, but without any trace of edginess that might creep in with a lesser preamp. The highest frequencies are extended and revealing but with a slight laid-back twist. The whole tonal character of Fulcrum resembles a lot of a high-tier R2R DAC for example.

Soundstaging is another really strong side of Fulcrum preamp. It’s vast in all directions. Width goes beyond the borders of your speakers, and depth is equally impressive. Instruments inside of the soundstage are well separated and sound quite three-dimensional themselves. Combined with that bold and weighty tonality, we get very good physical believability of every instrument or vocal being played.

This preamp can pull off some impressive dynamic swings too. In terms of micro-dynamics and speed, it’s capable but will not match leaner and meaner sounding devices. That said, I feel it’s as fast and as nimble as you can expect from a device that sounds weighty and palpable. This kind of sound reminds me of a curvy lady who has all of her curves in the right places and moves with grace. I’m not using euphemisms for fat here – I’m talking more about Salma Hayek’s or Kat Dennings’s kind of curvy here. Yes, a gymnast or a model can be more fit and chiseled, but you should ask yourself if that is what you really want. I want Salma and Kat.

Comparison

Schiit Freya+ is a much more affordable tube preamp that offers three modes of operation. Passive mode and buffered mode are just not a match for Fulcrum in any way. They sound more congested and grainier. Tube mode, when really good tubes are used is my favorite. I managed to get a really good speed and resolution from Freya+, I also managed to get a great holographic and three-dimensional soundstage. However, Fulcrum combines high resolution, high three-dimensionality, and very palpable sound with a very authoritative bassline in its one mode of operation. Whatever I do with Freya+, I never manage to make it sound as if it is not a step down from Fulcrum, in one of the areas at least. This is expected given the price difference and Freya+ is in this comparison just to check if Fulcrum is not an overpriced piece of gear.

EAR Yoshino 868 is a high-quality, highly regarded, tube preamp I had with me for a week or so, but didn’t have enough time to review it. It’s priced similarly to Fulcrum which makes it a much more fair comparison. It was tested with its factory default tubes. EAR preamp sounds even bolder and fuller. Tones with EAR 868 have a very smooth, almost liquid-like continuous character that Fulcrum can’t fully match. Vocals are so weighty and physical that I can truly believe someone is standing between my speakers. The soundstage is also very three-dimensional, but it is narrower. The Fulcrum preamp sounds both wider and airier. There’s also more precision with edges and quick transients with Acoustic Invader. The tone texture is more pronounced, and the bassline has more control.

Long story short, Fulcrum feels like a quicker and breezier preamp of the two. Yoshino 868 is fuller and fattier sounding but also slower and darker of the two. Both are great and both can be preferred according to your taste and system matching.

Acoustic Invader Preamp (classic model) is a quarter of the price and has all the same functions. Their J-FET topology is very similar too. The build is not as premium but it’s still high quality, and the same goes for the parts used inside of it. Sonically, they are much more similar than they are different, but there are a few differences. For starters, Fulcrum has more bassline grunt and authority. Inner tone texture is also more pronounced and things like vocals and wind instruments sound harmonically richer. The difference is noticeable but is by no means anywhere close to the price difference. This leads me to the conclusion.

Conclusion

An audiophile friend of mine said this – Fulcrum’s biggest problem, market-wise, might be the existence of the classic Acoustic Invader’s classical preamp at a fraction of the price. He has the classic model. I owned it too when I decided to try the Fulcrum. I compared them directly and agreed that the sonic difference is nowhere near what the price difference suggests. I still bought the Fulcrum in the end. It was a great price deal admittedly, so it was a much easier decision. But why did I do it?

Well, no matter how small the difference is, advanced-level audiophile sickos always crave for better. Also, I won’t pretend to possess the depth of character I don’t – it’s very seductive to experience a fine product like this. It feels so nice to own it and just touch those majestic knobs from time to time. Just knowing what kind of crazy high-quality parts are used in it pleases me too. Finally, it truly does sound fantastic and I did have a great deal on it that I didn’t want to pass. Luckily for me, I caught a great woman early in my life, who understands my passion and the sometimes unreasonable wantings that come with it. And while I can’t say this product is an easy recommendation for everyone – it’s a hell of a product for sure. So if you’re anything like me, you just might enjoy it enough to think it’s worth it.

NOTE: The often-asked question on my YT video is how can one order an Acoustic Invader product. While the brand has a website, it is horribly out of date. Instead, it is better to write an e-mail to Goran at acousticinvader@gmail.com or hit up Acoustic Invader’s social profile on Facebook or Instagram for pricing or any other information. Hope the website will be upgraded in the future while the brand matures.