[SolarCetacean]

I'll be visiting LTA next Friday for a demo of the Z10e and Aero. I'll be bringing my Ferrum Erco Gen 2 for a DAC comparison and also because I'd like to evaluate the Z10e by itself. Headphones will be the Stax SR-X9000 and possibly the Shangri-La Jr and MDR-Z1R depending on how much I want to put in my car.

 

[George Hincapie]

I bit the bullet as well. Looking forward to re-creating my experience demoing the naked unit and a Z10e at LTA last year. Let's keep their staff busy fulfilling orders!

Nice - let's compare initial impressions.

 

[George Hincapie]

I'm interested in learning more about the chains that new Aero DAC owners will be deploying.

What I am considering is:

Roon Nucleus > Fibre > Rose RS-130 or Lumin U2 > LTA Aero DAC > LTA MZ3 > Headphones

The streaming transport is one of the final pieces in the puzzle. Costs are the same, technology is really similar, but physically different. The Rose is more visually appealing, the Lumin more functional.

Headphones wise, I am considering divesting my ZMF fleet. I just don't enjoy them as much as my Arya Stealth. I have never really been blown away by them sonically - perhaps sacrilege to admit. Please don't lynch me.

I want to audition HE1000SE and Audeze LCD-5. Susvara would be a great place to stop, but I don't think that MZ3 can't drive them to their full ability.

 

[SHXMD]

Interesting.

Will post after arrival of new Auralic S1 streamer and Aero settle in.

 

[George Hincapie]

Interesting.

Will post after arrival of new Auralic S1 streamer and Aero settle in.

I saw a YT review of the new Auralic two piece streamer. Looks very neat; almost dCs Lina like....

 

[Killerb]

I'm interested in learning more about the chains that new Aero DAC owners will be deploying.

What I am considering is:

Roon Nucleus > Fibre > Rose RS-130 or Lumin U2 > LTA Aero DAC > LTA MZ3 > Headphones

The streaming transport is one of the final pieces in the puzzle. Costs are the same, technology is really similar, but physically different. The Rose is more visually appealing, the Lumin more functional.

Headphones wise, I am considering divesting my ZMF fleet. I just don't enjoy them as much as my Arya Stealth. I have never really been blown away by them sonically - perhaps sacrilege to admit. Please don't lynch me.

I want to audition HE1000SE and Audeze LCD-5. Susvara would be a great place to stop, but I don't think that MZ3 can't drive them to their full ability.

I have Bluesound streamers for convenience of a single interface because I have three systems between home and office. I also like that they are small and can be hidden to reduce clutter. I would also be interested in opinions on sources into the Aero, my local shop is high on a Margules streamer so I plan to demo it.

 

[SolarCetacean]

Yesterday afternoon I spent several hours at LTA HQ demoing the Z10e and the Aero DAC. I also brought along my Ferrum Erco Gen 2 for comparison. The Z10e's independent, per-input volume control was very useful for volume-matched comparisons between them.

For reference, the Erco Gen 2 acquired a number of technologies that were originally developed for the Ferrum Wandla DAC such as an improved discrete I/V converter as well as an improved apodizing digital oversampling filter developed in conjunction with the creator of HQPlayer. So the comparison is between an ESS9028Pro-based DAC with a solid-state output stage plus mini-HQPlayer built-in and a non-oversampling R2R DAC with a tube output stage. I listened with the stock tubes, which are 12SN7s with the GE label on them.

I had the preconception going into the demo that the Aero would be "tube-like", warmer, softer, thicker, bassier, maybe a bit smoothed over or rolled off in the treble with a bit less detail. All of the adjectives that people like to use for tube gear. Well, the Aero didn't fit that mold. I could not hear any lack of detail vs the Erco, which is impressive. I thought that the Erco Gen 2 with its improved upsampling filter was a notable improvement in detail perception from the Gen 1 Erco, and the Gen 2's improvements were similar to what I heard when using HQPlayer on my PC audio setup. And the Aero matches it in detail without any oversampling, with tubes in the output stage, and with a legacy 18-bit R2R chip as its DAC.

I'll go into more detail on its sound in a future post, but I got an interesting tidbit from conversation with LTA's Nicholas about the input board on the Aero. As noted earlier in this thread based on pictures of the internals, the Aero uses an input board from HEM, which is the parent company of Ferrum Audio. I asked if it was possible to port the Wandla's digital filters to the Aero given the use of the board, but the Aero only uses the input controller board while the digital filters are implemented on a different board on the Wandla, so the hardware isn't available to use oversampling filters. Nicholas also said that it was nice to work with HEM, which I like to hear.

 

[George Hincapie]

Yesterday afternoon I spent several hours at LTA HQ demoing the Z10e and the Aero DAC. I also brought along my Ferrum Erco Gen 2 for comparison. The Z10e's independent, per-input volume control was very useful for volume-matched comparisons between them.

For reference, the Erco Gen 2 acquired a number of technologies that were originally developed for the Ferrum Wandla DAC such as an improved discrete I/V converter as well as an improved apodizing digital oversampling filter developed in conjunction with the creator of HQPlayer. So the comparison is between an ESS9028Pro-based DAC with a solid-state output stage plus mini-HQPlayer built-in and a non-oversampling R2R DAC with a tube output stage. I listened with the stock tubes, which are 12SN7s with the GE label on them.

I had the preconception going into the demo that the Aero would be "tube-like", warmer, softer, thicker, bassier, maybe a bit smoothed over or rolled off in the treble with a bit less detail. All of the adjectives that people like to use for tube gear. Well, the Aero didn't fit that mold. I could not hear any lack of detail vs the Erco, which is impressive. I thought that the Erco Gen 2 with its improved upsampling filter was a notable improvement in detail perception from the Gen 1 Erco, and the Gen 2's improvements were similar to what I heard when using HQPlayer on my PC audio setup. And the Aero matches it in detail without any oversampling, with tubes in the output stage, and with a legacy 18-bit R2R chip as its DAC.

I'll go into more detail on its sound in a future post, but I got an interesting tidbit from conversation with LTA's Nicholas about the input board on the Aero. As noted earlier in this thread based on pictures of the internals, the Aero uses an input board from HEM, which is the parent company of Ferrum Audio. I asked if it was possible to port the Wandla's digital filters to the Aero given the use of the board, but the Aero only uses the input controller board while the digital filters are implemented on a different board on the Wandla, so the hardware isn't available to use oversampling filters. Nicholas also said that it was nice to work with HEM, which I like to hear.

So did you order an Aero?

 

[SolarCetacean]

So did you order an Aero?

Not... yet. I'm looking to buy a house, and the market is pretty difficult right now. But once the dust settles from buying and moving and all that, I'm considering an LTA combo with the Z10e. It certainly has that sort of modern classy look to it that would fit well with the aesthetic I'd want in my house.

 

[SHXMD]

Nice but houses come and go!

Superior tube audio equipment designed over two years by people who care are forever!

 

[SolarCetacean]

So, on to my more detailed sound impressions. All of these impressions were with the SR-X9000 and the Z10e amp. The Aero used the balanced inputs while the Erco Gen 2 used the RCA inputs. I'll use a few broad buzzwords to start, then dive into each one. The Aero with stock tubes, compared to the Erco Gen 2, is more midrange-centric, slightly more forward, slightly more "raw"-sounding, and has a bit more body to the bass, and has some selective treble emphasis. I'll go through a few tracks that I used to come to these impressions.

* Nurko & NERIAH - "Love Is a Highway": This is a future bass EDM track with a lot of upper treble content as well as vocals that are a surprisingly useful benchmark for DACs. At 0:27, when NERIAH sings "somethiiiing inside", the Aero doesn't overly smooth it over and renders this bit of vocal rasp so it's like "somethi-i-i-ng inside". Some DACs or filter settings will be too smooth there and lose that vocal texture; the Aero does not. Vocals in general are a bit raspier, a bit more "raw" on the Aero. They're also slightly more forward, or at least they seem to "pop" a bit more on the leading edges of notes.
Then there's an odd thing I didn't expect; in the drop starting at 1:39, there's notably more treble energy on the Aero compared to the Erco. I had volume-matched the comparison using the Z10e so that in the verse and build-up the two DACs were volume matched when switching between them, but the drop was significantly more treble-heavy on the Aero than the Erco. The Aero sounded brighter while the Erco sounded more subdued in comparison. I didn't do an in-depth comparison on the Shangri-La Jr, but I'm quite curious because the Jr has more upper treble, so the Aero may not play well there.

* Dabin & Dia Frampton - "Bloom": Another EDM track, the rawer vocals and midrange emphasis of the Aero were clearly heard on this track. The sound was also slightly more forward, in line with the rawer sound. The Aero also had slightly more body to the bass notes starting at 1:00 and through 1:55. This extra body is despite the bass being slightly lower in presence/volume vs the midrange compared to the Erco's rendering of the song.

* Emma Hewitt - "Into My Arms": This an atmospheric indie pop song. Hewitt's vocals sound a bit more textured on the Aero with the sound overall a bit more forward vs on the Erco 2.

* Chelsea Guo - "La Gazza Ladra: Di piacer me balza il cor": A piano + vocal performance. The Aero was a bit more vibrant in the strikes of the piano keys.

* Pittsburgh Symphony Orchestra and Manfred Honeck - "Beethoven Symphony No. 9: Finale": The Aero rendered a bit more stridency in brass instruments in their entrance at 4:47, making them... brassier for lack of a better term. More lifelike I suppose.

Overall, the Aero makes the sound slightly more forward and slightly rawer, and with a smidge more body to some percussion notes. I found that it had the most consistently beneficial character with acoustic music like the last two test tracks I listed. With modern electronic music, I think the differences are sometimes more obvious, but possibly undesirable depending on taste.

The main bugbear I have is that I actual dislike forward vocals, and the Aero has the overall effect of projecting vocals slightly more forward. Fortunately, this forwardness is not coupled with any sort of loss of spatial layering. There's still layering despite the sound moving forward slightly. The X9000 is quite sensitive to forwardness and I've heard DACs like the Gen 1 Erco where the sense of frontal space and depth just collapses on the X9000 and I get a 2D sound sheet. The Aero avoids that pitfall.

In some respects, I find the Aero to share similarities with my Sony Walkman ZX707. It's analog stage also uses a non-feedback design and it too adds a bit of body to the sound while having some treble accentuations that often make the resulting sound a bit more lifelike, like cymbals have a small bit more splash and excitement. My Walkman however adds a notable warmth and bassiness to the sound which the Aero avoids.

One thing to note is that the Aero is quite sensitive to its source. I used the USB input to a PC running Roon, and initially Roon's Invert Phase option had been left on, probably from a prior listening test. Inverting phase on the input resulted in crackling distortion occurring from the Aero during certain tracks. I thought it was the Aero having trouble with digital clipping or intersample overs, but then I noticed that Roon's DSP was enabled and turning off the phase invert fixed the crackling.

Sound-wise, the Aero was a surprise to me. It certainly didn't fit my preconceptions of what a tube DAC would be. I certainly didn't expect a treble emphasis from it. I'll go into my broader musings about the Aero in another post, but I'm keen on giving the Aero another demo, because it is certainly an interesting sound.

 

[SolarCetacean]

My original plan going into the LTA demo was that the LTA chain would be a warm and smooth setup to complement another more energetic electrostatic setup. This demo cleared up my mistaken preconception. The Aero is not a warm, soft, and smooth DAC, at least with its stock tubes. It is on the same level of detail as the Erco Gen 2 and it can sometimes be brighter with more treble energy. This requires me to re-evaluate what role I'll use it for.

The main decision point I need to consider is what direction I want to go with my audio setups vs what the Aero offers. The Aero only supports PCM input up to 192 KHz, so it is not well-suited for use with HQPlayer. HQPlayer's DSD conversion would be unusable and its PCM upsampling would be stunted by the Aero's low supported sample rates. HQPlayer would work much better on a Holo DAC which is also non-upsampling R2R, but supports extremely high input rates as well as DSD input so that HQPlayer can flex its filters. If I went with the Aero, it would not be in a PC-based setup where HQPlayer is used. Besides, the Aero looks too nice to be plopped on a desk behind a keyboard. I'd want it in the living room or den where it can be part of the room's furniture.

The Aero, on the other hand, grants me the privilege of tube rolling I haven't been much of a tube-roller, but that's mainly because Stax tube amps (the only tube gear I own) are difficult to tube roll due to using uncommon tubes (6CG7) and not auto-biasing, so wrangling with single-turn potentiometers to get the offsets within range was not fun. The Aero allows both 12SN7 and 6SN7 tubes, which are more plentiful, and they seem to auto-bias, which takes the hassle out of switching tubes. I met the designer of the DAC and he had been trying out different tubes which supposedly have a smoother sound. He switched them back to the more detailed stock tubes before my demo. It was very quick and easy to switch out the tubes, and the DAC didn't need to remain off for 15 minutes before powering it back up again, which is nice for tube rolling.

I'll definitely look out for more demo opportunities because I'm intrigued by the Aero, but I need to figure out where and how it will fit with what I want from my audio gear.