Vitus SIA-025 review

[jazzhead]

Bodhi , congrats and glad you are getting on well with the Vitus . I know it to be a refined amp , but how does the dynamics compare to the your Boulder pre/power ? Enjoy the ride .

Originally Posted by PlanarSpeakerFan

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

Hi Ken,

Thanks for your comments Actually in the latest review for HiFi Critic, Martin Colloms measured the S5's at 88db efficiency into a nominal 4 ohm load with a 2.4ohm dip, so i'd describe them as a moderate load. The Vitus does a great job of controlling the S5's. Btw, I like the xa-100.5's. Matched with the right speakers, they produce warm, tube-like liquidity and midrange bloom without tubey colorations. They also look stunning imho

Cheers,

Originally Posted by jazzhead

Bodhi , congrats and glad you are getting on well with the Vitus . I know it to be a refined amp , but how does the dynamics compare to the your Boulder pre/power ? Enjoy the ride .

Hi Jazz, thanks for the congrats In terms of how the 025 compares to my previous Boulder combo, 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 (though without the normal tube colorations). You just forget about the amp and 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.

Coming back to your original question re: dynamics. The Vitus has a large and efficient UI-core transformer and is a very high current amp. It is also very fast, so it is capable of properly controlling the S5's and matching them for speed. In saying that my Vitus, S5's, and most of my cables only have around 150hrs on them at this stage, so it's too early to offer any meaningful opinion on how the two amps compare. Hope that helps!

[PlanarSpeakerFan]

Originally Posted by Bodhisattva

Hi Ken,

Thanks for your comments Actually in the latest review for HiFi Critic, Martin Colloms measured the S5's at 88db efficiency into a nominal 4 ohm load with a 2.4ohm dip, so i'd describe them as a moderate load. The Vitus does a great job of controlling the S5's. Btw, I like the xa-100.5's. Matched with the right speakers, they produce warm, tube-like liquidity and midrange bloom without tubey colorations. They also look stunning imho

Cheers,

Thanks David for your comments on the XA-100.5. As you know, once you've had Class A amps in your system it's hard to go anywhere else. Matching up the Revel Salon 2's with the XA-100.5 was very easy because this was the same system my local dealer had in his showroom. After a couple of 2 hour listening sessions, I was totally sold. It was a match made in heaven. It sounds like your SIA-025 and S5's produce the same sort of terrific synergy. How did you come to choose your Vitus/Magico combination? Also, how are you liking your Romulus? My friend has the Pandora and is ecstatic with it.

Cheers,
Ken

[Orb]

Originally Posted by Bodhisattva

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

Hi David,
out of curiosity did have you compared the SIA-025 in class AB to that of the RI-100?
I am wondering just how they compare in that mode as I assume they are a very similar topology but with some very different hardware (such as the transformers and I assume caps,etc).
More of a audio hobby interest as I would use the SIA-025 mostely in class A like yourself, but definitely would be interesting to know just how close or what sounds better in AB (appreciate SI-100 is only AB).

Thanks for the review and photos
Cheers
Orb

Originally Posted by PlanarSpeakerFan

Thanks David for your comments on the XA-100.5. As you know, once you've had Class A amps in your system it's hard to go anywhere else. Matching up the Revel Salon 2's with the XA-100.5 was very easy because this was the same system my local dealer had in his showroom. After a couple of 2 hour listening sessions, I was totally sold. It was a match made in heaven. It sounds like your SIA-025 and S5's produce the same sort of terrific synergy. How did you come to choose your Vitus/Magico combination? Also, how are you liking your Romulus? My friend has the Pandora and is ecstatic with it.

Cheers,
Ken

Hi Ken,
Yes I agree Class A has a warmth and fluidy to it that is addictive. Gaining the benefit of hearing different amp/speaker combinations in your Dealer's showroom is a big advantage as is allows you to firstly discover what sounds good to you & gain from your Dealer's experience. Basically that's how I got to know the Vitus amps and Magico speakers. My Dealer always has both brands in the showroom, and i've had numerous opportunities to see, touch and heard those combinations and ask questions. I was really impressed by the SIA-025, loved the S5's, and had already heard the Q1's sound haunting with the SIA-025, SCD-025 and Siltech Royal Sig series cables, so I knew what to expect.

The Aesthetix Romulus has really surprised me. For the money, it is a beautifully put together tube player. The fact that is sounds beautiful seems to be a result of cause and effect. To me, it sounds natural, well balanced &
liquid/free sounding. Music flows really nicely. It is obvious Aesthetix invested most of thier money in the circuit design. There is very good attention to detail. To quote Yogi Bear...smarter than the average bear!

Originally Posted by Orb

Hi David,
out of curiosity did have you compared the SIA-025 in class AB to that of the RI-100?
I am wondering just how they compare in that mode as I assume they are a very similar topology but with some very different hardware (such as the transformers and I assume caps,etc).
More of a audio hobby interest as I would use the SIA-025 mostely in class A like yourself, but definitely would be interesting to know just how close or what sounds better in AB (appreciate SI-100 is only AB).

Thanks for the review and photos
Cheers
Orb

Hi Orb,

I haven't compared the RI-100 and SIA-025 operating in Class a/b side by side, but I have heard them on several occasions separately. It is easy to detect the differences however.

Firstly the two amps are quite different. The SIA-025 as I mention in my review uses a potted, floating UI-core transformer co-designed with & custom made by one of the best transformer designers in Denmark. The UI-core transformers are used exclusively in Vitus's Signature & Masterpiece series amps. The Reference Series use traditional toroidal transformers. Toroids only have two advantages over Vitus' UI-core, they being price and size. In every other way the UI-core is more refined, and much more efficient.

Also, the signature series parts are qualified to a higher level of specification compared to the Ref series. The SIA-025 is a true balanced dual mono amp, whilst the Ref series is not. The 025 operates in class a, the Ref series does not. The 025's preamplifier stage is made from one single "buffer" module which is also used in the SL-102 preamp, whilst the output stage is drawn from the SM-010 mono amps. So whilst I regard the Ref series amps as very good, they can't touch the SIA-025.

The RI-100 sounds powerful, has that analogue-like Vitus house sound, but I would say it is on the slightly dark side of neutral, and just a touch warm. In comparison to the SIA-025 it sounds a bit more 'raw' and less refined. But taken for what it is, it is an excellent value imho. The SIA-025 operating is class a/b is still warmer sounding that the RI-100 and sounds remarkably good. I suspect it is highly biased in class a, meaning at low volumes it sounds very close to the 025 operating in class a mode, but loses a bit of warmth, clarity and sweetness from the music. At higher volumes and after several hours run time the difference becomes more obvious.

Having the ability to switch from class a to class a/b is a cool feature. I switch over to class a/b for movies & background listening mainly.

Cheers,

[PlanarSpeakerFan]

Originally Posted by Bodhisattva

Hi Ken,
Yes I agree Class A has a warmth and fluidy to it that is addictive. Gaining the benefit of hearing different amp/speaker combinations in your Dealer's showroom is a big advantage as is allows you to firstly discover what sounds good to you & gain from your Dealer's experience. Basically that's how I got to know the Vitus amps and Magico speakers. My Dealer always has both brands in the showroom, and i've had numerous opportunities to see, touch and heard those combinations and ask questions. I was really impressed by the SIA-025 and loved the S5's and already heard the Q1's sound haunting with the SIA-025, SCD-025 and Siltech Royal Sig series cables, so I knew what to expect.

The Aesthetix Romulus has really surprised me. For the money, it is a beautifully put together tube player. The fact that is sounds beautiful seems to be a result of cause and effect. To me, it sounds natural, well balanced &
liquid/free sounding. Music flows really nicely. It is obvious Aesthetix invested most of thier money in the circuit design. There is very good attention to detail. To quote Yogi Bear...smarter than the average bear!

Hi David,

It sounds like you have a great dealer over there in Melbourne. It is a big advantage hearing everything you want to purchase in the same location. It really helps to take the guess work out of the equation. You knew what you wanted and you got it...awesome!

I've heard the Romulus multiple times and I'm always impressed with its smooth and organic sound, and its tremendous build quality. I've had the opportunity to speak with Jim White in person about it. He's a very talented designer with his "new school" tube circuitry that perfectly toes the line between accuracy and warmth. He's also not afraid to leverage the skills of other designers to get the results he wants, including Charles Hansen of Ayre Acoustics for zero negative feedback and Gordon Rankin of Wavelength Audio for asychronous USB.

Happy Holidays and Enjoy the Music!
Ken

Originally Posted by PlanarSpeakerFan

Hi David,

It sounds like you have a great dealer over there in Melbourne. It is a big advantage hearing everything you want to purchase in the same location. It really helps to take the guess work out of the equation. You knew what you wanted and you got it...awesome!

I've heard the Romulus multiple times and I'm always impressed with its smooth and organic sound, and its tremendous build quality. I've had the opportunity to speak with Jim White in person about it. He's a very talented designer with his "new school" tube circuitry that perfectly toes the line between accuracy and warmth. He's also not afraid to leverage the skills of other designers to get the results he wants, including Charles Hansen of Ayre Acoustics for zero negative feedback and Gordon Rankin of Wavelength Audio for asychronous USB.

Happy Holidays and Enjoy the Music!
Ken

Thanks for the insight on the Romulus cdp Ken. Interesting. Having previously owned an Ayon CD-5s, count me impressed! Another tube guy who I admire is Tim DeParavacini, but his work reminds me of the earlier Vac amps with average build quality, but talented circuit design. The Romulus otoh is put together like a Mercedes Benz. What's not to like?

Merry Christmas to you and your family.

Regards,

[yuh]

Hi David, I would like to say thanks for a great review.

I'm new to the forum, and interested in this amplifier as an upgrade into hopefully what could be my end game set up.

Currently i'm running a pair of Parasound JC-1s into Paradigm S8s. The JC-1s have the nice class A sound and is highly biased into class A for the first 25W (and class AB for the rest of the 400W). I was wondering with the Vitus, in class A mode, does it do the same thing, ? ie move automatically from class A to AB, or is 25W the limit? Which would make me worry about clipping into distortion etc.

Whilst the S8s are quite efficient speakers, I would want to upgrade them as well in the near future, perhaps to Evolution Acoustics MMMiniTwos or Magico S5 / Q3. That is if i can ever find a dealer in Sydney that can demo them...