Vitus SIA-025 integrated amp

[David A]

I posted this review in Cafad's Addicts Guide to Integrated amps, but thought it deserved its own thread . Most regular members would be aware of Victor's SIA-025, so i'll constrain my comments to my personal experience. 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 130hrs 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?

 

Edited February 8, 2014 by Bodhi

[darthlaker]

Very nice Bodhi! I am sure it sounds sublime!

 

Please post some more pix.

 

And welcome back to SNA!

 

[Luc]

Yeah Bodhi, welcome back.

 

It's a small amp too.

[Phantom]

Sorry if this is a dumb question but how can a new member be welcomed back?

 

I get the welcome part but not the back part.

 

In any case................Welcome

[Rob181]

Yeah Bodhi, welcome back.

 

Ditto...good to see you back...may your posts reign long...Rob

[maximus]

Nice write up Bohdi. I heard the S5's driven by a vitus r-100 with killer results, they were sublime. Quite amazing how a 25watt class A amp can control those 10 inch woofers. Most well known

brands would fall on their backsides, but in fairness the Vitus is a high price to pay.

I often wonder where reputed Class A amps ie : Luxman 509ax and Accuphase E-560 at 1/2 and almost 1/3 of cost would compare simply for a costing exercise.

Anyhow super system Bodhi.

cheers Frank

[David A]

Thanks guys for the warm welcome Fyi Phantom I was banned from the forum 2 years ago due to biting in a flame thread & have just been allowed to rejoin. You live and learn as they say, and life moves on.

Edited December 15, 2013 by Bodhi

[Luc]

David, have you ever listened to a Sugden pure class A?

[David A]

Nice write up Bohdi. I heard the S5's driven by a vitus r-100 with killer results, they were sublime. Quite amazing how a 25watt class A amp can control those 10 inch woofers. Most well known

brands would fall on their backsides, but in fairness the Vitus is a high price to pay.

I often wonder where reputed Class A amps ie : Luxman 509ax and Accuphase E-560 at 1/2 and almost 1/3 of cost would compare simply for a costing exercise.

Anyhow super system Bodhi.

cheers Frank

Thanks very much Frank . Were you referring to the SIA-025? (as the RI-100 is a 300 watt class a/b amp). I've heard the S5's driven by the RI-100 which certainly has lots of power and control & shares Vitus' dna, whilst the SIA-025 still has plenty of power and control, but is the warmer, more fluid and musical sounding amp of the two.

 

I'm not sure how the Luxman and Accuphase class A integrateds would compare as I haven't heard them in the same room, however the SIA-025 in particular pushes the engineering and parts quality far beyond the Lux and Accuphase imho .

Edited December 15, 2013 by Bodhi

[David A]

David, have you ever listened to a Sugden pure class A?

Hi Luc, no I haven't had the opportunity. They look pretty funky though

[strony]

Welcome back Bodhi

nice to se eyou posting and lovely amp btw.

 

Cheers

Andrew

[David A]

Welcome back Bodhi

nice to se eyou posting and lovely amp btw.

 

Cheers

Andrew

Thank you kindly Andrew for your welcome and comment

[unclemack]

Looks like the sort of amp that could last a lifetime... Congrats mate. A great piece of HiFi. I have to say though, when I saw the price, I nearly sharted!

 

I heard Martins Luxman Class A here the other week and that was beautiful. I can only imagine how sweet this would sound...

 

Cheers

 

M

[David A]

Looks like the sort of amp that could last a lifetime... Congrats mate. A great piece of HiFi. I have to say though, when I saw the price, I nearly sharted!

 

I heard Martins Luxman Class A here the other week and that was beautiful. I can only imagine how sweet this would sound...

 

Cheers

 

M

Thanks mate I can't disagree with your comments, especially the one about the price! :lol: The Vitus sounds wonderfully pure and mellifluous. It just gets out of the way and gives you music.

 

There is a lot to like about the current Luxman line, especially the D-08 sacd player. Industrial design and build quality are top notch. But there is no doubting the great synergy between Vitus and Magico.

 

Cheers,

Bodhi

[Guest Muon]

More pics!

 

Tops off is good

[David A]

More pics!

 

Tops off is good

I'll get onto that soon Ortofun! My camera doesn't take great flash photo's, and the best light in my room is mid-morning. None the less i'll see if I can squeeze off a few good shots one night after work..

[AudioAddict]

Hey Bodhi, really enjoying both your threads. Loved reading your impressions of the Vitus Sia-025. Just curious as to how you think it would compare to the Vitus ss101mk2 or ss102. Any experience or thoughts?

[Batty]

Thanks guys for the warm welcome Fyi Phantom I was banned from the forum 2 years ago due to biting in a flame thread & have just been allowed to rejoin. You live and learn as they say, and life moves on.

Has it been 2 years already.

[David A]

Has it been 2 years already.

I could have my maths wrong Batty, but it certainly felt like 2 years!

[sir sanders zingmore]

Bohdi, how did the Boulder pre + power combination sound compared to the Vitus integrated?

I assume there would be some good "house" synergy there

[David A]

Hey Bodhi, really enjoying both your threads. Loved reading your impressions of the Vitus Sia-025. Just curious as to how you think it would compare to the Vitus ss101mk2 or ss102. Any experience or thoughts?

Thanks for those thoughts AA I recently heard the ss102 driving a pair of YG Sonja's in my Dealer's showroom. That was the first time i've sat down and enjoyed listening to a pair of YG's. The big Vitus does a great job of taming the YG's tendency to sound bright. In terms of how the two amps compare, clearly the ss101/102 and sl102 will have better performance than the sia025. That also comes at a price and in most cases the 025 will be more than enough. In munich last year Vitus used the 025 with a pair of focal stellars in a 300m2 room with 4m to the ceiling and it rocked big time. The ss101 and ss102 offers more control and precision, but the 025 offers a much more "romantic" class A type sound.

Edited December 17, 2013 by Bodhi

[David A]

Bohdi, how did the Boulder pre + power combination sound compared to the Vitus integrated?

I assume there would be some good "house" synergy there

Hi Trevor, I actually never set up the 1010 preamp as about that time I decided to reduce my box count and go in a different direction with my system (ie: toward a warmer, more musical sound). I can offer some thoughts on how my previous 1060/Ayon CD-5s combo compares to the Vitus. The Boulder is tomb quiet, has excellent control and bass and is overall natural sounding. It is not clinical or dry sounding like Spectral, and is neutral in tonal balance. If anything it is on the very slightly warm side of neutral. The CD-5s with mil-spec tubes and burson op amps added some tube virtues of warmth, sweetness, liquid sound and holography. Sound stage depth and width were excellent. That's not to overstate the influence of the Ayon. The sound was dominated by the Boulder. I would say the Vitus is more delicate and warmer sounding overall. Once the 025 has been running for a few hours it becomes wonderfully pure and tube-like. You just forget about the amp and just enjoy the music. The Boulder otoh always makes you aware of it's presence, like a percussionist playing Timpani in an orchestra. That may be due to the Boulder's more forward presentation and predominant bass. The Vitus also has strong, deep bass but it is somehow more in harmony with the music. Hope that helps!

[David A]

After speaking quite a bit to Hans Vitus and reflecting on the sound of this amp, I went back this afternoon & re-wrote a couple of bits of this review to correct one error and more accurately portray the sound of the amp. Small but important details.

[sir sanders zingmore]

Hi bodhi, just wondering why you felt a need to change your personal opinion of the sound of the amp after talking to Mr Vitus?

[David A]

Hi Trevor, actually the only thing I changed after chatting to Hans Ole was a factual error about the bias of the amp in Class A/B mode. I previously (incorrectly) described the amp as being highly biased in class a/b mode. I clarified this with HOV who provided this response - "In pure kl. a the sia025 is biased to give a full 25W into 8 ohm in kl. A but still runs into 100W ab - with no switching. When switched into ab mode - the bias is lowered to about 5w kl a simply to save power." I think with time and reflection, this amp has revealed it's sound and character more to me such that I have a clearer picture of what was always there. Actually I only changed one word describing the sound. See if you can pick which one...

Edited February 9, 2014 by Bodhi