Aqua Hifi Formula Optologic DAC

Device Type: Digital to Analog Converter
Availability: Authorized Dealers
Price: $14,000
Full Specifications
Product Manual

It means light. Light is used to couple the digital to the analog boards instead of metal/wire so that electrical noise stays away from the analog circuitry where it can do all kinds of harm we can hear. The "A" in DAC stands for Analog which seems to go without saying but some people get stuck on the "D" making the false assumption that digital is "perfect". As perfect as free-range unicorns.

Italy's Aqua Formula Optologic DAC is a discrete resistor ladder DAC (R2R), look ma no off-the-shelf DAC chips, just like my resident totaldac and the recently reviewed and much loved Holo Audio Spring DAC (Alex liked it so much, he bought one). More to the point, AudioStream reviewer Ola Björling reviewed the Formula's less expensive stablemate, the Aqua Hifi La Scala MkII Optologic DAC, and I think it's safe to say he liked it, too.

A reader recently asked, "What is it about ladder DACs?" to which I wanted to reply, "It's the way they sound."

Here's Ola on R2R tech.:

The R2R design principle uses a repeating cascaded structure of resistor values R and 2R (or even just R, if you’re ok with using more of them), and fewer components in total compared to some other designs. Fewer resistors to match means more precision, but R2R constructions require incredibly accurate component matching for the most significant bits, and that demand only rises with word length. On the positive side, a DAC designer employing this approach has much more wiggle room for creativity and fine tuning than with a chip, and in this case the “optologic” part has to do with the resistor ladder D/A conversion being optically rather than electrically connected to FPGA’s that process the signal further.
Isn't that a nice concise explanation? I think so. In brief, the digital signal in the Formula is processed by FPGAs (Field Programmable gate Array) which Aqua has programmed to pass data without upsampling. It's here, at the FPGA's output that the opto-bit comes into play as the connection between the FPGA and the four resistor ladder boards is all glass. Light. There are a total of six digital inputs with single-ended and transformer-coupled balanced outputs. I used the latter for the entirety of this review because properly implemented balanced outputs are better than single-ended. The Formula can pass PCM sample rates up to 384kHz (via USB, Ethernet and S/PDIF max out at 192kHz) and DSD64 (via DoP).

Being just-a-DAC, the Formula's face is pretty simple consisting of power, mute, and phase switches on the left, eight green LED-lit sample rate indicators, and a series of switches for selecting the input. There's also an included, and nicely built, big IR remote. So, no volume control and no headphone amp which is perfectly A-OK by me. YMMV. In terms of looks, the Aqua's aluminum faceplate (available in satin silver or satin black) and anti-resonant Nextel cabinet is understated and cool (looking, imo). At nearly 20 pounds, it's also reassuringly beefy (see the Aqua website for details about all of the high-grade parts inside, which includes separate power supplies for the analog and digital bits).

The company likes to stress the modularity of their DACs and I would too as offering owners the ability to enjoy future upgrades is where it's at. There's nothing worse than buying something only to learn that it has become the old model within a few months of purchase. Talking modular, the Formula's inputs are just that and Aqua also offers AT&T (ST Fiber) and Optical Toslink input modules if you so desire.

Do Not Resist the Ladder
I spent weeks and weeks listening to the Aqua Formula Optologic DAC for two reasons; this is what I typically do with review gear and, more to the point, I enjoyed the heck out of listening to it. The Formula is a tight, clear, and refined music maker. I can hear why people like it and why some people, like AudioStream contributor and full-time Digital Audio Review(er) John Darko loves the Aqua La Scala MKII Optologic (OK I don't think he said "love" but the La Scala sits at the top of the DARKO DAC Index in the Premier League). It was due, in part, to John's prodding that this review happened.

When I say the Formula is a music maker, I mean it. I'm going to let Alex Halberstadt say what I mean (from his Holo Spring DAC review):

Because even the best digital had what I came to think of as a look-but-don’t-touch quality. It’s as if you were a shabbily-dressed tourist walking through a store that displayed beautiful, expensive objects in locked glass cases. You could see them but could never handle them. Not a single digital component allowed me to connect to my music, to physically revel in it, something I could dependably pull off with even a modest turntable. (Later, I was surprised and weirdly delighted to discover that Michael Lavorgna used a similar metaphor—a sheet of glass separating the listener from the music—when describing his experience with most digital playback.)
Yea what he (and I) said! The Aqua Formula joins the rarefied air of music making DACs that shatter digital's glass. Because I listened to the Formula for weeks and weeks, I heard a lot of music through it. All kinds. Even more kinds than "large-scale classical", "female vocals", "jazz", and "Hotel California". I like to joke about being an audiophile because there's much about our fine hobby that's worth laughing about. One of them is the notion of "test tracks" or the proverbial short short list of music we use to put gear through its paces. Serious stuff. Here's what I think; the more we rely on "test tracks", the farther we get from the entire point; the enjoyment of music. Music being plural and much broader than any short short list.

Boris' new one, Dear, is body-crushing goodness (how do they get that tone?) and my system in the barn with the Formula converting digital to analog made for some real drama. The big question on my mind, and I'd imagine some of yours, was—how does the Formula match up to my totaldac D1-six which comes it at $14k and change? With Boris playing I had to know so I switched to the d1-six which was connected to the microRendu/USB, while the Formula had been riding AES/dCS all-the-way. A simple switch of source in Roon and input on my Ayre and I was comparing in no time flat. Let me also add it had been weeks since I listened to my DAC so the differences were rather dramatic.

The totaldac offers up a larger, more colorful, and more vivid sound image as compared to the Formula. It's as if my music was more fully formed to my liking with the French DAC whereas the Italian sounded a bit cooler and in more control. I'd almost go as far as to suggest that by comparison, the totaldac is more rapturous and the Formula more business. Yea, my preferences lean heavily toward rapturous but that doesn't mean yours does and it also doesn't mean that we have a winner. What we have is difference.

I would also call the Aqua Formula a master of the infinitely small, where nothing goes unnoticed. To clarify, I'm not talking about detail or digital etch, I'm talking about musical information that can get buried in the mire of reproduction. This ability allows the Formula to present a wonderful sense of scale and along with it, drama. Nice.

For fun, I switched inputs on the DACs, moving the Formula to microRendu/USB and the totaldac to dCS/AES and the differences I described remained. I prefer AES, when available, as properly-implemented AES is a better link than USB. "Oh, wait a minute." someone said continuing, "USB goes all the way to 384kHz while AES maxes out at a measly 192!" Piffle! (I say). No really, piffle. And I say piffle because focusing on sample rates instead of the quality of the DAC with all music is like focusing on the ingredients in a wedding cake to decide if you are going to like your blind date.

I Want To Take You Higher
If you are looking for a DAC and have 14,000 clams (or more) to spend and want to listen to your music and enjoy every last bit of it, I'd recommend listening to the Aqua Hifi Formula Optologic DAC. I wouldn't be surprised to learn you love it.

Also in-use during the Formula review: totaldac d1-six, dCS Network Bridge, microRendu/UltraCap LPS-1 power supply

Associated Equipment

Alex Halberstadt's picture

Free-range unicorns.

JIMIXY's picture

Will you review any Denafrips DACs? eg, Pontus

Michael Lavorgna's picture
I was trying to imagine what you meant to type ;-)

This company is new to me. I will check them out. Thanks!

JIMIXY's picture

Definitely worth looking into, a great deal of grassroots hype developing around this company, mainly due to the quality for the money alleged and due to the four models being R2R and native DSD compatible and three of them also having a switch to compare Oversampling (OS) and Non Oversampling (NOS) methods.

Denafrips Pontus (2nd up model of four) pictures here -

pdxdon's picture

These days, I mostly listen to Tidal, since I love having access to so much. The quality of the music making (by the artist and my system) is variable, but I am curious. To get my system to really sing and get my monkey mind to revel in the sensations still requires me being present and a fairly high level of recording quality. I can also enjoy a lower standard of recording, just in a different way (there is an analogy to sex here). Being content is not a bad thing since you can't be driving 200 mph in a Lamborghini all the time. The gear is good if it lets you reach "the clouds and the rain" occasionally.

bobflood's picture

that so many of these DACs come with such stratospheric prices. Is this DAC really 6x better than the Holo DAC Level 3 that you reviewed and referenced in this review? It should be at least 3x better at nearly 6x times the price! JA was right when he said that soon most high-end product will not even be visible to most potential buyers.

Michael Lavorgna's picture
If something strikes you as having a "stratospheric price" just move on to something that doesn't.
bobflood's picture

misunderstand my intent. I was merely questioning the value proposition not the right of manufacturers to charge what the market will allow or the right of anybody to buy whatever they feel is a good value for them.

In the past, I have purchased equipment in this bracket and might again if I should find something that I think is worth the price. I will be replacing a very high-end DAC that is aging out and I will look at both the high-end and more moderately priced alternatives and I will decide based on the value proposition that is best for me.

Michael Lavorgna's picture not determined by the price of something. As you say at the end of your comment, "for me", which says it all.


GarkM's picture

Is the DAC mostly the cause for the "breaking the glass" or does the rest of your system deserve some of the credit?

To my surprise recent use of JPlay software has increased my connection to the music over previous budget digital audio. I'm using:

JPlay ($115) > AQ Jitterbug ($50) > iFi Nano iDSD LE ($130)

Also experimenting with Raspberry Pi solutions but so far no reach out and touch.

Michael Lavorgna's picture
While I kind of squirm when I hear that, in this case it's an OK answer: My room and system certainly play a part in the entire picture but those things remain (fairly) constant so I can focus on DACs and such.
R1200CL's picture such an expensive DAC. I find that strange. Also how volume is controlled is essential as I understand you may loose bits if done wrong or in the cheap way. Maybe something to be discussed in a separate article.

One of the best reviews I ever read.