Vitus SIA-025 review

Hi folks, having lived with my Vitus SIA-025 for a while, I thought it was time to post a review. Firstly the Vitus has wonderful Danish industrial design that is timeless. Everything about its design and attention to detail is excellent right down the the shipping materials and remote control (which is the best i've ever seen & is rechargeable). The SIA-025 is a true balanced, dual mono, 25 Watt class A amp which uses an efficient Vitus-designed UI-core potted "floating" transformer with separate windings for the left & right channels. The preamplifier stage is made from one single "buffer" module which is also used in the SL-102.. so .. really good, whilst the output stage is drawn from the SM-010 mono amps. The Vitus in every respect is the best integrated amp i've owned by a fair margin.

This amp is very flexible and has 100 watts of class a/b power @8ohms which is perfect for background listening or for movies, but can also be switched over to class A mode for best sound. At power up the amp defaults to class a/b operation and a moderate volume level of -46db from memory which I like, though i've heard atleast one other audiophile state he'd prefer the amp default to class A. I personally like the factory settings however.

But all that build quality would be useless if it didn't sound good! The easiest way to describe the sound of the SIA-025 is it sounds like real music. It avoids straying into sterility or sounding analytical by offering up a nice balance of warmth, tonal purity, richness (body) and tube-like liquidity. The Vitus has excellent resolution which reveals subtle, but important information in the music such as a bell chime in the background, or the light brush of a snare drum. It also has fast transients and can be delicate when the music calls for it. The treble is somewhat softened and the lower midrange slightly emphasised, giving the amp a sound resembling good vinyl. And the effect is cumulative as you add more Vitus components. In short, Vitus sounds best with other Vitus components. In saying that however, the SIA-025 is remarkably flexible. Not only because it can be switched from class a/b to class a, but also because this amp has the uncanny ability to sound good paired with a range of speakers and setups. It just "does its thing" and always produces great sound. Perhaps its ability to make average recordings sound very good extends to less than perfect speakers?

I also strongly agree with Chris Thomas's comments in his HiFi Plus review in which he stated -

"From stand-by, straight into class A I would say that you are looking at a half hour before it really begins to sing and then it just seems to keep getting better. Even after a solid afternoon and evening's listening I would swear that the amplifier was growing more fluid, textural and resolute with better dynamic contrasts, tonal shading and the delicacy of its musical message just seems to become more profound."

As a side note, good isolation is very important to bring out the best sound from this amp. Notwithstanding the potted, floating transformer and anti-resonant chassis, stuffing so much gear into a modest sized chassis does create some resonance. Placing the amp on a solid rack with Stillpoints Ultra 5's and an Ultra LPI on top made a big difference which created a blacker background, improved bass & brought the sound stage into clearer focus. I now consider the Stillpoints mandatory with the Vitus Sig Series such has been the level of improvement.

But has it got balls? That is a question I get quite a bit. With "only" 25 watts class A power, on paper it doesn't look like this amp is capable of driving a full size speaker with a moderately difficult load. Let's look a bit deeper. Most of the amp's real estate (and 42kg weight) is taken up by a huge 1.4kVa Vitus-designed UI-core transformer. Most audiophile-grade toroidal transformers lose up to 25% voltage (both channels driven), however the Vitus loses max 1.5% voltage tested. It is also a very high current amp, meaning that 1.4kVa tranny feels more like a big 2kVA tranny. In practice I have found the SIA-025 drives my Magico S5's without breaking a sweat and at only 140hrs is already delivering deep bass and a nice, coherent sound stage. Of course once my amp and speakers reach 500hrs the bass and sound stage should open up even more & sound more resolving.

In summary, this is a sublimely good integrated amp. I never thought i'd find an integrated which would convince me to dispose of my previous Boulder 1060/1010 combo, but the Vitus achieves that feat and sounds like very good high end separates. That revelation coincided with a wish to reduce my box count and change direction with my system. What I didn't realize at the time was how much of a sea change that would prove to be!

Cheers,
Bodhi.

The Vitus securely packed on its own plastic pallet..



Initial setup..





On my Taoc rack with Stillpoints Ultra 5's installed..





With both Taoc racks installed..



So what's under the hood?..

[Masterlu]

David... Super nice, looks very well made; glad you are enjoying the new addition. Great pics too, keep us posted as it breaks in!

Thanks Ivan . The Vitus is already sounding great. I will post another update when it reaches 250hrs, and again when it reaches that magic number...500hrs

Cheers,

[PlanarSpeakerFan]

Hi David,

Beautiful looking integrated amp and very well built. I bet it sounds fantastic with the S5. As a jazz lover, I can see the advantage of being able to switch to pure Class A to enjoy jazz vocals, piano or small combos. Then switching to Class A/B for big band, Santana or Tchaikovsky at full tilt. Seems like all bases are well covered.

Enjoy,
Ken

[willyjack]

So cool to find a component that meets all your needs. Congrats.

[CLEE]

Excellent write-up. Vitus gears seem to synergize well with Magico speakers. I am tempted.

Originally Posted by PlanarSpeakerFan

Hi David,

Beautiful looking integrated amp and very well built. I bet it sounds fantastic with the S5. As a jazz lover, I can see the advantage of being able to switch to pure Class A to enjoy jazz vocals, piano or small combos. Then switching to Class A/B for big band, Santana or Tchaikovsky at full tilt. Seems like all bases are well covered.

Enjoy,
Ken

Thanks Ken There is no doubt that Magico speakers have great synergy with Vitus. The S5's are great "all rounders" and sound terrific with a wide range of music. With Norah Jones, this combination provides an engaging sound and feeling of intimacy. The Vitus imbues Norah's voice with warmth and delicacy, and provides correct tone and body for piano and acoustic guitar. It seems to serve jazz, female vocals & brass instruments particularly well and provides warmth, richness and life to these styles. It should be mentioned the S5's also do a great job of handling large, complex orchestral pieces without getting flustered.

Re: switching from class a to class a/b, to be honest i'm having a hard time getting the Vitus to run out of steam in class a! I find I only really need to switch it over to class a/b for movies. But it is nice to be able to switch over to class a/b for background listening also

Cheers,

Originally Posted by willyjack

So cool to find a component that meets all your needs. Congrats.

I agree, and thanks Willy

Originally Posted by CLEE

Excellent write-up. Vitus gears seem to synergize well with Magico speakers. I am tempted.

Thanks Clee I agree. When I was auditioning the S5's, I heard them paired with a range of amps including the Dart separates, Vitus RI-100, Vitus SIA-025, Audia Flight Strumento pre/power & the Soulution 710/540 combo. Of those, I liked the Soulution 710 the most, followed by the SIA-025, but can more easily live with the Vitus. And i've found adding further Vitus components has a cumulative (positive) effect as I mentioned. Btw, another member told me Vitus' current production run of SIA-025's are sold out, and new orders wont be delivered until March, 2014. So they must be doing something right

[PlanarSpeakerFan]

Originally Posted by Bodhisattva

Re: switching from class a to class a/b, to be honest i'm having a hard time getting the Vitus to run out of steam in class a!

Cheers,

David,

This is a great problem to have! I also would stay in the Class A mode if there's enough steam. Sounds like the S5 is not too difficult a load, which is a good thing. I've never even moved the needles on my XA-100.5 (which denotes leaving Class A).

Best,
Ken