Riviera AIC-10 sound tests
My equipment for the tests
- Qobuz Hi-Res – Roon
- Innuos Zenith mkIII streamer
- Chord MScaler + Dave DAC
- Abyss TC with superconductor cable
- Focal Utopia with Danacable Lazuli Reference cable
- Various other cables which I will spare you this time…
Going bananas
Apparently, this is one of those things you shouldn’t try at home and certainly not without parental supervision… however, curiosity was too strong and I did a little experiment which was already mentioned here by the always resourceful
@simorag
Connecting the Abyss TC to the Riviera speakers’ output with banana connectors is a sure way to get to heaven! BUT BE CAREFUL NOT TO BLOW UP YOUR HEADSET BY KEEPING VOLUME DOWN.
Speakers output basically gives a larger and deeper soundstage without fundamentally impacting the transparency and overall tonal balance.
Remember that I am talking here about shades, small details and differences, and I that I need somehow to magnify my perceptions in order to describe them (that’s what hi-fi is all about right?). There are no “night and day”, earth shattering experiences in my world!
All the tests below have been done through speakers output for the Abyss TC and through 6.35 headset output for the Utopia comparing each to the Dave output, which for me is a reference of transparency and fidelity to the source.
Mullard ECC82: long plate, D getter, Blackburn, 1958
A much sought after, UK manufactured tube. This is the most euphonic tube I have.
Abyss
The Riviera paints a very big, 3D sonic landscape, with a sweet, involving, relaxing, slightly warm sound signature. But make no mistake, it remains very dynamic and impactful.
Compared to the Dave output, the Riviera has a good dynamic range, it puts a bit of emphasis on mids and lows, highs are a bit rolled off. It is a bit less transparent but still doing very well and it has more “body". The soundstage is amazing, much larger, taller and deeper.
Perfect for orchestral music, with effective, “tactile” reproduction of the different sections of instruments.
On small jazz groups or chamber music, instruments are larger, with fuller bass and more impact. The tonal balance is a touch darker. The loss of transparency is slightly more noticeable on direct comparison. Spatial clues are much better. I just love how it reproduces the tone of a bass clarinet, or the low keys of a closely mic’ed piano. Female voices are gorgeous, not hyper detailed but very engaging.
In short, if you want to be seduced by the music and forget about the rest, this is your tube.
Utopia (Lazuli reference)
The Riviera/Utopia combo is fun and decidedly tilted towards a mids-lows. Strong impactful bass, larger scene and instruments.
In short: not very accurate for acoustic music but great for pop, rock, bass heavy music types.
La Radiotechnique 12AU7WA: O getter, 14 mm plate, military use, 1950s
This is a well-balanced tube by the French subsidiary of Philips.
Abyss
The Riviera is airy, punchy, precise but never shrill, with instruments clearly placed in a large scene.
The reproduction of acoustic double bass is fantastic: I feel the vibration and slap of a big tensed string. Bass go very deep if needed, remaining structured, defined. Percussions are equally impressive, fast when appropriate, resonant. I can easily imagine the leather being hit.
Voices are very precise, less sweet than with the Mullard, more realistic (which can be good or bad depending on the recording). Strings and in particular violins are pleasantly reproduced with detailed but controlled highs.
Compared to the Dave output, the Riviera has a very similar tonality, transparency is almost on par, but it sounds more effortless, more impactful, instruments are less edgy and better defined (double bass for example). Highs are very, very slightly rolled off: I can detect that only with a careful comparison and it results in a less fatiguing listening experience. The scene is larger, taller, deeper but less than with the Mullard.
In short: if you want a pleasantly dynamic and realistic listening experience, this is your tube.
Utopia (Lazuli reference)
As many have reported here, the Utopia-Lazuli-Mscaler-Dave setup is hard to beat, which is way I was very curious to hear how the Riviera would do. And the Dave has certainly more than enough power to drive the Utopia.
Compared to the Dave, the Riviera sounds very very similar, same tonality and almost same transparency (which is rather amazing), slightly better and larger 3D effect, slightly bigger instruments, more weight to the notes and better controlled highs.
Conclusion: the Riviera in low gain makes the Dave output redundant. I would never buy it alone for the Focal but it is amazing to see how it matches and improves over this setup.
Dario / Radiotechnique 12AU7, 1956
This is the tube I am using these days and I love it. It’s another RT model, built differently. I was surprised to see how it flares up for second when turning on the amp!
It is very close to the RT above. In my notes I wrote vivid, detailed, dynamic, impactful. I think is adds a touch to the mid-range in a nice way. The Utopia benefits even more, along the lines of what I wrote above.
Conclusions: even less famed, very affordable tubes can be great finds!
NEW! Mullard CV491 k61, Blackburn, 1956
This looks identical to the Mullard ECC82 reviewed above, I cannot see the getter though. It was built for use by the UK military. I wonder whether it has different construction features, or it simply passed a more thorough quality test compared to the ECC82.
They sound the same and have the same impressive 3D scene, a great tube!
NEW! Fivre 12AU7 “412”, 1954
These two Fivre (see below) are a mystery to me and unfortunately there is very little information about codes, years, production sites etc. Their construction share many similarities (plate structure, micas, style of codes printed and etched on the bottom) but also some differences (grey and black plates, connection of the getter to the mica). Sound wise they are opposite!
The “412” is warm and dynamic, not dissimilar from a Mullard. There some small differences especially in the spatial representation but I am not able to pin them down. I would put them in the same basket. Recommended.
NEW! Fivre 12AU7 “575” 1950s
The “575” is a katana
, by far the most transparent and detailed tube I own.
Abyss TC
The Riviera is transformed in a super Dave: fast, detailed, transparent. Scene is a bit wider and larger via speakers line, the Dave alone seems a bit flatter. I do not notice any roll off of highs, violins are detailed, female voices are very realistic and they can present some hiss if that’s in the recording. Bass is not more present compared to the Dave but more controlled and very well defined. The overall presentation perhaps lacks a touch of “weight” that balanced tubes like the RT provide.
Conclusions: a very peculiar tube that requires careful choice of albums to be enjoyed with the TC. On well recorded, warm tracks it shines; a few times I had the weird feeling that the Riviera was more transparent than the Dave (is it actually possible?).
Utopia Danacable LR
That’s an easier pairing due to the warmer tone of the Utopia. The tonal balance is very similar to the one with the Dave, the transparency is on par. The Riviera is better especially with a slightly larger and deeper scene and bigger instruments.
More tube fun in the future
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depending on the mood, music genres, headphones/loudspeakers signature etc.
