Ferrum Wandla D/A preamplifier

I can roll out of bed and install a $10,000 phono cartridge while finishing my coffee, but I postpone DAC installations until I am in the exact right mood to handle the potential stress—especially DACs with a touch screen and a complex menu. To my delight, Ferrum Audio's new Wandla digital converter was completely stress-free to install. It took only minutes to connect the USB-C cable, the Cardas Audio Clear Beyond interconnects, and 24V DC power adapter.

Connecting the power adapter caused a power-switch symbol to appear on the front panel touch screen. The moment I touched it, I smiled like the Cheshire Cat, because I saw a USB-C symbol, a loudspeaker symbol, three dots in a box, and a volume control bargraph. That told me the Wandla recognized my chosen input and was waiting for a signal. All that remained was for my Roon Nucleus+ server to recognize and enable the new DAC, which it did without prodding or reprimand. For me, that was a wow moment, a good start to what promised to be an interesting review.

I reviewed Ferrum's first product, the trailblazing HYPSOS stand-alone power supply, and their second, the OOR headphone amp in Gramophone Dreams #57 and found them both to be smart and good-sounding—an auspicious start for this new company from Eastern Europe. These first products led with style and followed with innovation and thoroughly considered engineering. The software control in the HYPSOS felt like it was designed by engineers who knew what they were doing and finished the job. In today's feature-obsessed marketplace, that's rare.

Ferrum products are made in Poland at an engineering and manufacturing company called HEM that was founded at the beginning of this century. For its first 20 years, HEM was a highly respected "OEM" making digital and amplification products for other companies. The HYPSOS was their first product under their own Ferrum banner. Since my OOR and HYPSOS reports, Ferrum has introduced two more products: the $1795 ERCO DAC/headphone amp and the $2795 Wandla DAC/preamp, which I will be describing here.

The Ferrum Wandla is a two-channel digital/analog converter that comes in a stylish-looking, modestly proportioned chassis measuring 8.6" wide, 8.1" deep, and 2" high and weighing only 3.9lb. The Wandla's chassis matches cosmetically and stacks perfectly with Ferrum's HYPSOS power supply, which is recommended with the Wandla but not required.

The Wandla's conversion job is handled by an ESS Sabre ES-9038PRO chip, which, according to the ESS data sheet (footnote 1), "handles up to 32-bit 768kHz PCM, and DSD256 via DoP and native DSD1024 data in master or slave timing modes. Custom sound signature is supported via a fully programmable FIR filter with 7 presets."

The Wandla offers three of those ESS filters plus two "HQ" filters created for Ferrum by renowned filter maker Signalyst, known for their work on the HQPlayer app. These filters are called HQ Apodizing and HQ Gaussian. The others are ESS Linear Phase, ESS Minimum Phase, and ESS Apodizing.

The Wandla sports a full roster of back-panel digital inputs: AES3, supporting PCM rates up to 24/192 and DoP up to DSD 64; TosLink (PCM up to 24/96); electrical S/PDIF on RCA (PCM up to 24/192); USB-C (PCM up to 32/768, DSD up to DSD 256); HDMI ARC (PCM up to 24/192); and I2S (PCM up to 32/768, DSD 256). The Wandla offers full MQA decoding.

The Wandla has one analog input; the single-ended signal stays analog and becomes "truly balanced" internally; the Wandla's analog circuitry is fully balanced. There are two analog output pairs, one RCA and one XLR.

In a Positive Feedback interview (footnote 2), Ferrum Founder and CEO Marcin Hamerla stated, "Perhaps the most important part of the Wandla is the completely new I/V circuit, i.e., the current-to-voltage converter, which connects the DAC IC to the rest of the converter circuit. Our new I/V chip, completely developed at HEM, is the main element responsible for the Wandla's sonic signature."

During my auditions, I presumed that the main cause of the Wandla's high ease-of-use factor was that "All software, including the USB interface, was developed in-house at HEM." Say amen, brothers. The warranty is for three years.

Listening with line-wart supply
Before the Wandla arrived, I had already decided to start my auditions with compositions featuring impact and rhythm, with drums playing heavy beats loud. I decided this because DACs employing sigma-delta chips, and especially the esteemed ES9038PRO used in the Ferrum, have higher punch, slam, and PRaT factors than most NOS R-2R DACs, which in my systems show good PRaT—but not conspicuous PRaT—and direct my attention more toward lyrics and melody.

I started this month's auditions with the Wandla connected directly to the Feliks Audio Envy 300B headphone amplifier, which I auditioned for this month's Gramophone Dreams column. I opened the Envy's volume control to full and operated the Wandla's with its sturdy palm-sized remote. This simple system exhaled resolution and clarity.

I played the marching Mamady Keïta composition "Djabara" off Keïta and Sewa Kan's album Wassolon (24/96 FLAC, Mamady Keita/Qobuz). This drum-powered track revved my brain completely. The Wandla playing Wassolon using its wire-wart power supply seemed well-suited for this kind of music, as were HiFiMan's reference-quality HE-R10P planar magnetic headphones, which, in concert with the DAC and amplifier, brought a high level of verity to Wassolon's voices, drum, and bird sounds.

In lieu of audience applause or jangling keys, I use bird sounds to test a component's ability to reproduce complex, low-level harmonics. With the Ferrum DAC, these drum and bird sounds felt immediate and vital, but the body of the sound felt brittle and pinched.

Drums enjoy being sigma-delta-ed, and so do pianos. The Wandla driving the Feliks Envy powering my HiFiMan R10P planar magnetic headphones turned high-speed rhythms, fast turns, and airy piccolos into a delirious aural fantasy.

My lifelong crush, Martha Argerich, delivered a dazzling version of Tchaikovsky's Nutcracker Suite, arranged by Nicolas Economou, on Winter Music (16/44.1 FLAC, UME/Tidal). PRaT was off the charts. Thrills came easily. But compared to the considerably more expensive Denafrips Terminator Plus, melodies felt inhibited, and there was a subtle but distinct metallic hardness that infused the body of every note. Reverb tails were shortened. When I double-checked these observations with JPS Labs' Diana headphones and through my Heretic AD614 speakers, that metallic hardness was still there. Those experiences inspired me to connect Ferrum's HYPSOS power supply.

Help from the HYPSOS
My Cheshire Cat smile returned when I connected the Wandla to Ferrum's hybrid digital-analog HYPSOS power supply. The OLED display lit up, indicating that the HYPSOS had recognized the Wandla and was feeding it 24V DC without stress or menu-reading meltdowns. (The Wandla will work with any DC voltage between 22V and 30V.) I only like digital when the sound is stress free, and when the software makes my life easier, not more cussingly convoluted. The Wandla-HYPSOS hookup made menu-surfing a pleasure.

The $1195 HYPSOS mated instantly with the $2795 Wandla, creating a hip-looking two-chassis $3990 DAC. The HYPSOS's effect on sound quality was immediately obvious. That hardness was relieved. Martha Argerich's Winter Music became supple and distinctly more three-dimensional with clear, vibrating open spaces between notes.

This power supply upgrade is something I wish every audiophile could experience. It is not subtle, and it leaves no doubt about how much a component's source of energy affects the flow, luster, and body of reproduced music. I am curious to see if John Atkinson will detect a difference in the Wandla's measured performance using the optional HYPSOS.

Checking for accuracy of tone, I played violinist Midori's intense Bartók Violin Concerto No.1 Op.21, with Zubin Mehta and the Berlin Philharmonic (16/44.1 MQA Sony Classical/Tidal). My secondary goal was to compare the Wandla's MQA rendering to my memories of how spectacularly the dCS Bartók Apex played it—but alas! The Midori Bartók sounded off. The Wandla's touchscreen indicated that the Wandla was switching between MQA and straight 16/44.1, and that's what it sounded like. I checked Roon, and it showed it was inputting "MQA Studio." I tried another MQA file, this one featuring French pianist Samson François playing Debussy (16/44.1 MQA Parlophone/Tidal), and it behaved the same way.

After raising my eyebrows and shrugging my shoulders, I moved on to a 16/44.1 version of Samson's Debussy on Qobuz, and there, the sound was nothing short of glorious: full, bright, alive, and colorful. Listening with the Feliks Envy and the HiFiMan R10P planar magnetic headphones, the Wandla's tone was good, emphasizing the tinkly side of the keyboard. With Meze Elite planar magnetics, the left-center of the keyboard came forward, adding weight to the sound. The Elite's refined resolution made sustain and reverb tails into events worth savoring. The JPS Labs Diana headphones added more torque to the bass region.

Footnote 1: See esstech.com/wp-content/uploads/2021/03/ES9038PRO-Datasheet-v3.7.pdf.

Footnote 2: See positive-feedback.com/high-fidelity/ferrum-wandla-dac.

Aleje Jerozolimskie 475
05-800 Pruszków
(631) 246-4412

Glotz's picture

I wish I had the dosh for this and the power supply. Those filters seem like some next-level engineering. Another listen at AXPONA is in order for sure. Thanks for the review and your succinct conclusion- a great way to spend 1/3 to get $10k sound.

Purité AUDIO's picture

Doesn’t it work without Cardas Clear Beyond Belief cables?

Glotz's picture

Elvis Costello just approved of the latest iteration. The cables work fine.

kai's picture

I had liked to see measurements published comparing between HYPSOS and the wall-wart supply.
Or maybe just clearly mentioned if there aren’t any differences.

BTW: There’s a little typo in the underline of Fig. 18: “… output power into 8 ohms” should be 100 kOhms.

Anton's picture

"The distortion in both output types was extremely low at all audio frequencies, and the second- and third-harmonics lay at or below a vanishingly low –120dB (0.0001%) into high impedances (fig.19). This was the case with both the HYPSOS and wall-wart supplies.

Even when powered by its wall-wart supply, the Ferrum Wandla performed supremely well on the test bench with both analog and digital inputs, especially with the HQ Gauss reconstruction filter. It boasts very high resolution, very low distortion and noise, and a bombproof output stage."


I agree with you, it is very interesting to compare with and without things. On a slight tangent: pre and post "break in measurements" of things, especially speakers, could be very enlightening!


John Atkinson's picture
kai wrote:
I had liked to see measurements published comparing between HYPSOS and the wall-wart supply. Or maybe just clearly mentioned if there aren’t any differences.

The only difference I found and wrote about was that the random noisefloor, which was already low with the HYPSOS supply, was 6dB lower with the wall-wart. All other measurements were identical.

kai wrote:
BTW: There’s a little typo in the underline of Fig.18: “ . . . output power into 8 ohms” should be 100k ohms.

Thanks. I have fixed it.

John Atkinson
Technical Editor, Stereophile

georgehifi's picture

"was 6dB lower with the wall-wart. All other measurements were identical"

No need then to blow $1200 for the Hyposos power supply, the wall wart should be better, looking at the measurements.
Any wattage specs on the wall wart??

Cheers George

Ktracho's picture

I'm wondering if you tried using the Wandla as a preamplifier. Can it do double duty, or would you still need a separate preamp to get great sound if your other source is, say, a phono preamp?

John Atkinson's picture
Ktracho wrote:
I'm wondering if you tried using the Wandla as a preamplifier. Can it do double duty, or would you still need a separate preamp to get great sound if your other source is, say, a phono preamp?

The Wandla's measured performance as a line preamplifier is beyond reproach.

John Atkinson
Technical Editor, Stereophile

MBMax's picture

I continue to search for that next level with my fairly large CD collection, within my $ comfort zone of course. This Wandla would be stretching it, but I am really intrigued by the filter and voltage flexibilities and their impact on sound.

So... Herb, you auditioned many streaming selections in 16/44.1. Helpful.

For you, and others with streaming experience, what have you found with streaming versus CD's in general? IOW, can I generally extrapolate Herb's 16/44.1 streaming experience to what my CD experience might be?

Currently, depending on the disc, I switch between my old Marantz SA-8004 on board DAC and my MHDT Orchid R2R DAC. Both are quite nice. Both leave me feeling there's more to be had from my CD's. Friends, please tell me to knock it off if I'm just falling victim to audiophilia nervosa...

Meanwhile... thoughts on getting the most out of my CD's welcomed.

Jason Victor Serinus's picture

Speaking personally, I play files and stream music in all resolutions rather than play silver discs. It's easier, consumes far less space, and sounds great. As to which sounds better in 16/44.1, file playback / streaming the same files from Qobuz or Tidal / playing the discs, it depends on the quality of your playback software and hardware. On my system, the order of sound quality, with the best on top, is:

Files stored on my Innuos Statement Next-Gen's internal SSD
Files streamed from Tidal and Qobuz
Files sourced by my NAS which is powered by a Ferrum Hypsos hybrid power supply.

Note that my streaming network is highly optimized with an optical interface and top-quality ethernet, USB, and power cables. It has taken a lot of time and money to get where I'm at.

Short answer: There is no absolute "this sounds better than that." You need to experiment and listen.

I hope this is helpful.


MBMax's picture

But in a more immediate sense, what I am really after is how to optimize what I currently have, i.e. a few thousand CDs (along with probably 3K LP's, and a hundred or so reel to reel tapes).

I have heard enough goodness out of the variety of affordable DAC's and players I've owned that I can tell there is more to be had. The greatest change (mostly, but not always, for the better) I've experienced has come from the R2R ladder DAC rabbit hole. More analog sound though at times with the loss of some detail and vitality.

So, because of the significant differences experienced, I suspect I can do still BETTER, but my budget is not 5 figures deep for DACs, dedicated transports, separate power supplies, etc.

I guess my real question is this then: based on the experiences of my fellow music lovers reading this, what have you found (IF anything) that generally takes CDs to the next level? And, by the way, my food chain upper end in toto for DACs, USB cables, S/PDIF cables, power cables, etc. runs to maybe $5K for the sake of my marriage, budget, and conscience.

I have been tempted to jump into the Benchmark pool, the Bryston pool, and some other pools, but hesitate because, though auditions and 30 day trials abound, I have found that I really have to LIVE with a piece of gear for the long haul to truly know...

You pays your money, you takes your chances. For that reason, and that fact that most DAC reviews don't spend much time on CD reproduction specifically, I reach out.

No expectations, just sharing. Thanks for the feedback thus far...

Mark in Santa Cruz

Jason Victor Serinus's picture

I'd check out Herb's reviews of lower priced DACs. Also consider that the very first power cable in your chain has ramifications totally down the line.

Easiest solution. Many of your CDs are undoubtedly streamable, and some of those streams will be hi-rez. Put Qobuz, Tidal, or Roon on your computer, get a better cable interface, and connect to a streaming DAC.

Here's to long-lived relationships, with music helping to magnify the joy.


Jason Victor Serinus's picture

Some of my colleagues swear by its sound. And it costs far less than Roon.

MBMax's picture

And this brings me alllll the way back to what motivated me to write in the first place: this DAC under review by Herb is quite intriguing specifically because of the fact that the user has a lot of options to shape the sound.

Maybe I should just take the leap... (insert shrug and forehead smack emojis here).

Jason Victor Serinus's picture

See my assessment of the Ferrum front end at the Warsaw show. I was surprised by how good it sounded. You can always go with just the DAC and then spring for the Hypsos later on. If you don't hear the difference immediately, perhaps you can return. I'd check with them.

MBMax's picture

Taking a flyer on a Wadla with the ridiculously gracious encouragement of my wife along with Herb and Jason.

We shall see... er hear. Looking for endgame DAC for CD's. Perhaps?

And thanks for the tip on Audirvana. Will check it out!

Glotz's picture

Will charge you for the restock fee the last time I checked when I bought my HPA4 and when I returned cables that I didn't need. Important note to factor in when buying from them. You should be quite happy with their products, though I realize you would be looking at DAC3 family.

MBMax's picture

Thanks Glotz.

Hopefully the Wandla is a winner in my system and a return or resale is unnecessary.

Was leaning toward trying a DAC3 but... the flexibility of the Ferrum as extolled by Herb tipped me that way.

Also, research quickly revealed that an in-shop audition of this kit is nigh impossible anywhere near me. So I'm jumping in!

Jason Victor Serinus's picture

Now I wait in suspense to learn if it gives you what you want, or if the entire experience leads you to question the feedback and opinions of HR and JVS. Once your new baby settles in, please send an email and let me / us know. If you can't find our addresses, write us c/o stletters@stereophile.com.

Thank you,

MBMax's picture

You're a good cheerleader JVS.

Over the many years, I've never been misled by wise ol' Herb or the late, great Art D. As for you JVS, I've never really had the chance to test your audio judgment and wisdom, mainly because I'm in a much lower audiophile price orbit. But your feedback here was a good nudge.

Will report back when the new unit is broken in and making music. I'm looking forward to some fresh deep dives into my Mercury Living Presence boxes in particular, followed by a lot of Bill Evans, Joe Henderson, Lee Morgan, and many more.

This is a great hobby and dare I say family, conflicts, warts, and all.

Jason Victor Serinus's picture

Do check out Tom Fine's latest remasterings of the MLP catalogue.

georgehifi's picture

Your Orchid dac is similar to the Pagoda save that uses the TDA1541 chip while the Pagoda uses the PCM1704 chip (which I think is the better) but the way both are implemented leaves a lot to think about, as the distortion figures are through the roof at nearly 1.5%!!!!! and below 80dB dynamic range. I would look to a new dac that is at least <.005% to get more enjoyment from your CD collection.

Cheers George

ok's picture

streaming = casual
vinyl = natural
cd = intense

georgehifi's picture

streaming = casual
vinyl = natural
cd = intensely natural, if done well.

Cheers George

Jim Austin's picture

Thanks to everyone who has participated.

Jim Austin, Editor