Riviera thread, AIC / AFC / APL / AFM / Levante

Sovrce Gear
222

It’s somewhat hard to do without moving to to listen on the TotalDAC as a comparison. I might try that on Thursday if I get a chance.

I was going to leave more impressions until I had a chance to go back to the Viva, just to close the loop. But maybe it’s interesting to see how my impressions evolve.

I don’t think the AIC is a particularly neutral piece FWIW, to me it’s quite midrange/mid bass forwards. But not really in a traditional tube amp sense, in that I wouldn’t describe it as bloomy.
The way the mid bass presents is with a very distinct clarity, I can easily decern the shape of individual Bass notes, which speaks the very good control there, it’s just to me seems in your face in those frequencies.
I still think that’s why some male vocals seem to present somewhat recessed.

The background is very black, but it sometimes struggles to convey large scale dynamics effectively, I’ve been struggling to understand this, beyond it’s relaxed/polite presentation, a good example might be in the intro to Money for nothing, where it builds up to a crescendo, then the guitar comes in it just kind of happens on the AIC, rather than it being an event.

The tubes I have in the Lampizator I’ve selected to maximize dynamics, some people have described the 242’s as too much for some SS amps, so I know that’s all AIC. Though perhaps it’s something with the pairing.

Having said that I listened to Rumors by Fleetwood Mac yesterday, and that wasn’t really lacking impact.

I’m at a point where I listen to it, and think wow that sounds really good, but I’m easily distracted from what it’s playing, it just doesn’t at least yet pull me in.

Now that could be the tube, I have no way to tell. I’ll check what 12AU7’s I have in my big box of tubes, I know I have a Brimar, but those are kind of full bodied as well I’m not sure if I have an RCA on hand.

EDIT — looks like I have the Brimar, an RCA and an early 60’s JAN Raytheon

8 Likes
223

Well this is interesting, relocated the AIC to be near the TotalDAC, and it’s a very different Amp on the total DAC.
The Pacific clearly does not like it, I know the lampizator DAC’s struggle with low impedance amps, but the AIC a is supposed to be 50 Ohm input impedance, I’ve never heard such a dramatic change in the character of an amp.
The overly slow relaxed presentation is basically completely gone.

10 Likes
224

Photo from lampi hq

IMG-20221227-WA0000(2)
IMG-20221227-WA0000(2)1600×1200 202 KB

9 Likes
225

Interesting I know the Pentode based Lampizators have a different volume control design that alleviates at least some of the issue.
I guess it’s also possible the Levante behaves differently.
Or the tubes in the Pacific make a difference.

I mean this was not a subtle difference.
And I just swapped the Viva back in to ensure my Pacific wasn’t just broken

It’s a bit odd that an amp like the AIC-10 would be a problem for the Pacific to drive, assuming the input goes right into the tube stage, the input impedance ought to be effectively just be the volume pot.

The most obvious explanation for what I heard would be input impedance that decreases drastically with frequency, which does happen with some SS devices like Mosfets where the impedance is largely due to the input capacitance, but with tubes it’s just not an issue for audio frequencies.

2 Likes
226

My suspicion of the Lampi DHTs is that there’s quite a bit of variance in output impedance and voltage based on the tubes, more so than the non DHT stages.

I don’t sense anything particularly lacking in my Lampi-Rivera setup.

3 Likes
227

Yeah I’m sure it’s more a Pacific/AIC issue than a Lampizator/AIC issue.
Could also be just the 242’s, they have pretty high plate resistance, and that will affect the output impedance detrimentally.
Unfortunately I’ve moved it now, and I’m not moving it back to see if a Pacific Tube swap fixes it.
But I’ve never heard it have these sorts of issues with another amp. Or for that matter hear this dramatic a mismatch with any other pair of components.

Clearly neither component is broken, they just don’t like each other.

Anyway its a much better sounding amp with the TotalDac, I would personally probably still keep the Viva over the AIC, but it’s a much closer call.

I think the AIC has better definition in the midrange, especially in the mid bass, the mids are rich (though not in the tube sense of the word), it’s got a blacker background that the Viva, and it has solid macro dynamics.
Viva though wins out in Macro, might miss a little something in resolution, but it’s close, presents with a much more open airy stage, has it’s own lush midrange (though the presentation is different).

3 Likes
228

From Stereophile’s measurements for Levante:

The unbalanced input impedance was 44k ohms at 20Hz and 1kHz with the Mullard tubes, dropping to 36k ohms at 20kHz. The balanced input impedance was 42k ohms across the audioband. With the JJ tubes the unbalanced input impedance was 34k ohms at 20Hz and 1kHz, 30k ohms at 20kHz.

One of the things Lukas talks about in his Poseidon interview and I believe is also on the website is trying to solve input impedance mismatches that rarely happen between Lampi DACs and preamps. The Poseidon output impedance per phase is 400 Ohm

EDIT:
You can see it here in the design criteria for Poseido #6 and #7 (ignore the link title. Lampi are lazy)

2 Likes
229

It’s on the low side but not obnoxious, as I said it could be 242’s in my pacific.
Lampizator quoted me minimum input impedance of 20K Ohms with PX25’s they have like a 3rd of the plate resistance of the 242’s, so it’s quite possible 242’s are requiring higher.

I was also using SE on the pacific, which probably makes it worse, since you have in effect 2 tubes in parallel in balanced, and that basically 1/2’s the output impedance.

Yes I read something about part of the Horizon/Poseidon design is about better output impedance.

It’s more interesting that anything, as I said I’ve never heard such a dramatic mismatch. I’m glad I moved it to test on the TotalDAC now.

5 Likes
230

From Riviera about Levante:

generally speaking you can use any 12a*7 family tube without a risk of serious damage, but the levante is design to be used specifically with the 12AT7 and using any other tube will completely mess all specs.
We strongly suggest not to change the tube or to only stay strictly in the 12AT7 family where you can find anyway very good tubes (Mullard E180CC for example).

2 Likes
231

Weird they say that yet the e180cC/7062 differs to the 12at7…

E180CC/7972 has higher transconductance, and lower dynamic plate resistance - compared to the 12AT7. It also draws about 50 mA more heater current, and the glass bottle is about 3/8" taller than the 12AT7.

232

I believe the e180cc is close enough electrically to a 12at7 that it can be used as a low gain substitute for a 12at7. LTA said I could use it in my MZ3 (which used 12at7) but not in my Ultralinear+ (which used 12au7 & 12ax7).

My favorite tube in my MZ3 was actually a Miniwatt 18ecc (a substitute for a e180cc) in the 12at7 slot.

2 Likes
233

Good to know, I’ve run e180cc and now ecc40 in my levante (with adaptors).

I haven’t gone through the process in looking at how the specs compare between the two, my dealer tested the ecc40/adaptors in his levante before he shipped them (and he runs the same in his demo unit).

I do crave a set of fancy timber adaptors from the wbf seller at some stage

1 Like
234

Anyone notices a buzz or hum noise when using the speaker taps with Susvara? With the lcd24 its loud and can hear it even if music is playing so I stopped doing that, but with Susvara its way less and can hear it only when there is no music otherwise the music is louder than the buzz, sometimes the buzz is not there but its there most of the time.

The Amp is totally quiet from the headphones output. I’m using a generic low quality banana adapter got it just to test the taps before I invest, could this be because of the cable?

1 Like
235

There’s a lot of gain at the speaker taps, so it’s not surprising.
The headphone output is as I understand it run through a voltage divider, that will reduce everything including noise.
Bear in mind speaker sensitivity is quoted usually in db/w at 1m, headphones are quoted in dB’s/mW i.e 1000x more sensitive, so even very insensitive headphones like the Susvara, are far more sensitive than even the most sensitive speakers,
Tube likely has an impact, but it can also be just ground noise, which can be a function of the amp, the source, or just the way they end up connected.
It will go away if it’s the source, when you disconnect the source. Basically if it goes away with the input disconnected, it’s either the source or the way the source interacts with the Amp in your setup.
If it stays, it’s the noise floor of the amp, or the tube.
The one thing it’s almost certainly not unless it’s faulty is the cable to the headphones.

4 Likes
236

Thank you so much… Its the tube (Brimar cv4003), the stock JJ and Tele Ecc82 are quiet. Phew, would have never thought of changing the tubes.

On a side note, that Tele sounded mighty first time I plug it in a long time.

1 Like
237

I’ve had this happen with some tubes as well and noticed it more with Utopia than the much less sensitive Susvara. I ended up using the front output in some cases if I insisted on specific combinations.

5 Likes
238

First tube roll since I got the amp a month ago. Tungsram ECC40 (Foil Disc Getter, Long Welded Black Plate) NOS from 1952

IMG_3900
IMG_39004032×3024 719 KB

11 Likes
239

Got to hear Levante at @orrman place this weekend and directly compare it to AIC-10 with the same tubes, cables, and everything and figured I would post some impressions.

The Chain:

%%{init: {"flowchart": {"htmlLabels": false}} }%% graph LR K50[Antipodes K50] Lampi["Lampizator Poseidon<br> RCA 5u4g"] Levante["Riviera Levante<br> Dual G73r"] AIC["Riviera AIC-10-Bal<br> G73r"] Sus[Susvara] K50-->|FTA Sinope| Lampi Lampi-->|DHC Chimera XLR| Levante & AIC Levante & AIC -->|DHC Prion 4 Speaker adapter<br> -> DHC Chimera HP Cable| Sus

Everything was powered by Niagara 5000 with the only difference between AIC and Levante being Levante used a Riviera Power cable while the AIC used generic hospital grade one.

The Comparison

All of these notes are talking about on sus since we didnt use any other amps on the speakers to compare against. I would say the absolutely dominating trait of levante is “ease”. No matter what it does and what’s being ask of it, it sounds utterly effortless above the level of just having good flow or liquidity. I would call it a little relaxed as a result, but its in the absolute best way possible.

Compared to AIC (everything the same except for amp power chord from Niagara), clarity is a step up and stage is clearer as well. I am mixed on if stage was larger or not on an ultimate scale tbh, but I will say that levante utilized its stage more commonly. I do think that levante is a bit more relaxed than AIC, but in a way that feels like a direct step up from AIC, not in a bad way. AIC felt more likely to compress music slightly in comparison which gave some better slam and incision at certain times, but felt less true to what the music wanted.

Ultimately, same price for same price, levante is the very clear winner to me. I’m not exactly sure how much more I think the levante needs to be to not justify it for sus, but my gut check is if its more than 15-20% that would feel like pushing the limits for me. Obviously in terms of speakers its not the same math though.

9 Likes
240

Hello! Has anyone compared directly the Levante headphones output to the AIC-10?

I have two headphones, the RAAL 1995 Immanis and the Spirit Torino Valkyria. I drive the Immanis via the AIC-10 speaker taps and the Valkyria on the HP out, in HP-LOW mode.

After many years of forced hiatus, I have now the possibility of using loudspeakers again in my room, although headphones will likely be way more used given wife / condo neighbors constraints.

I would like to use a single amplifier for both headphones and loudspeakers, but if I keep the AIC-10 I will be forced to source very efficient speakers (say at least 93-94dB given my limited room size - 25sqm - and listening volumes) and with benign load, which would limit my choices significantly.

With the Levante I would have plenty of options for loudspeakers selection, but I fear the headphones out would not perform on par with the AIC-10.

4 Likes
241

The headphones out on Levante is incomparable to the sound quality coming from the speakers taps and although I didn’t compare directly, felt worse than the hp out on AIC10.

I ran headphones from the speakers taps on Levante and it’s amazing.

4 Likes