˻ PREMIERE ˼

⌈ FERRUM is a Polish audio brand of the company HEM, one of the most experienced companies in this industry, designing and manufacturing devices for MYTEK for 20 years before it went to their own. The first Ferrum product was the HYPSOS power supply. The second project was the OOR balanced headphone amplifier, the third was the ERCO digital-to-analog converter, and the latest top DAC, the WANDLA model. We are testing it as the FIRST IN THE WORLD. ⌋

HERE IS SOMETHING TO IT that in the last two years several Polish audio companies have gained a recognition around the world. And it's not so much that they "found their way" to audio shops, but that they became interesting and sought after by audiophiles. Without looking at the archives, off the top of my head, I can point out Gigawatt and Pylon (seniors in this group), Fezz Audio (RED Dot award), Felix Audio (present in every magazine devoted to headphones), J.Sikora (the highest awards of the "Stereophile" magazine and others), as well as Ferrum. The latter has been appreciated not only with the STATEMENT In High Fidelity award, but its products can be found in many editorial offices around the world as a reference point.

As it is emphasized, the first product with the Ferrum logo that left the plant in Pruszków, where the company's headquarters is located, was a non-obvious one. It would seem that power supplies are the domain of Far Eastern companies that can make them faster and cheaper, in large quantities. However, the Polish manufacturer proved that an innovative layout and interesting design are the key to success. The HYPSOS hybrid power supply has seduced people around the world - there are several of them working in the hifistatement.net editorial office alone.

This power supply was presented at the end of 2020, and we premiered it in the December issue of HF (more → HERE) same year. Let's add that this device received the STATEMENT in High Fidelity award (German Edition 2021; more → HERE).

Equally popular was the Oor headphone amplifier, which was introduced in mid-2021 (more → HERE). We liked this device so much that it received our BEST PRODUCT 2021 award. The third device was even more ambitious - it was the ERCO, a digital-to-analog converter equipped with a headphone amplifier (more → HERE). It was also honored with the BEST PRODUCT award, this time for 2022 (more → HERE).

There is something about these devices that, on the one hand, attracts attention due to innovative techniques and interesting solutions, and on the other hand, is interesting because they offer high-class sound, extremely immersive, and at the same time neutral. Such a combination happens less often than we would like. Therefore, every time we meet it, we have to recognize it, because it's worth it.

Even more so if it is a product described by the manufacturer as a "flagship" and which in the brochure is described as one that "changes the rules of the game in the audio industry". Let me present to you the WANDLA digital-to-analog converter.

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| A few simple words…

MARCIN HAMERLA
founder, CEO

⸜ A team of engineers who developed WANDLA: (from the left) Maksymilian Matuszak – Hardware Designer, Paweł Gorgoń – chief of R&D and Marcin Hamerla – CEO

WOJCIECH PACUŁA When did you start the development of Wandla?

MARCIN HAMERLA There is no easy answer to that question. We started Wandla Project more then one time, because each time we had to suspend the work as we weren’t fully satisfied with the results. The final stage, that eventually resulted in adding a new DAC to our lineup, started right after we finished working on Erco, which means in April last year.

WP How does it differ from your previous products and Mytek products?

MH Wandla is the culmination of our experiences gathered during the 25th years of designing and manufacturing audio equipment. So technically it is completely different from what we did in Mytek, and on the other hand it is the culmination of our development including such well-known products as Stereo 192-DSD DAC or Brooklyn DAC+.

Wandla is an innovative product, in which innovations concern both the digital and analog stages of the converter. The digital one, which in the Brooklyn DAC+ consists of five main chips, has been integrated into a single chip, efficient enough to run our new upsampling filters, developed in collaboration with Jussi Laako, the creator of HQPlayer.

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 in HEM, is the main element 'responsible' for the Wandla's sonic signature.

⸜ Oleksandr Promovych and Andrii Matusiv – they are responsible for assembling devices from components

WP Where did the name come from?

MH Our product names come from various European languages. In this particular case, we used a German word, but written phonetically. 'Wandler', pronounced 'Wandla', simply means... converter!

WP What did you focus on when working on it? Was the USB input programmed by you? What about digital filters?

MH As the name of the device suggests, we put the main emphasis on the quality of the conversion. We did not want to build a Swiss army knife, but a device that would perform the function which it was built for in the best possible way. That is digital-to-analog conversion.

At the same time, Wandla is so well thought out that it can be used universally, in various contexts and setups. And last but not least one of the key features is the so-called user interface - an intuitive touch screen. All software, including the USB interface, was developed in HEM. Digital filters, a strong feature of Wandla, were developed - let me repeat - thanks to the help of the creator of HQPlayer.

⸜ Jarosław Jabłoński – one of the most experienced HEM engineers

WP How does the volume control work?

MH The device offers two volume controls, a digital and analog ones through a digitally controlled analog attenuator. Signals from digital sources can be adjusted in two ways. Signals from the analog input, obviously, only using the analog control, because in Wandla we don’t use analog to digital conversion. We generally suggest using the analog volume control. It sounds great!

WP Who designed Wandla?

MH The R&D team at HEM currently consists of 6 people. They all were involved in the design of Wandla. The head of our R&D department is Paweł Gorgoń, and the person responsible for hardware is Maks Matuszak.

WP Can you tell us anything about company’s future plans?

MH We are already working on a new product, but as always we will release information about it shortly before its premiere. Which this time will probably take place around November. ●

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▌ WANDLA

WANDLA IS A D/A CONVERTER. That's how it's promoted. Unlike many other products of this type, it is not equipped with a headphone output, clearly stating that it is a specialized device. For those who want to use it in a headphone system, the company offers the Oor headphone amplifier.

The device uses exactly the same housing as previous devices from this company. It is small, measuring 217.5 x 206.5 x 50 mm (W x H x D; without knobs, feet and sockets), and weighs less than 2 kg. The chassis is made of bent stainless steel powder coated with black varnish, and the whole thing is placed on small rubber feet. On the side, an element made of a cornet was added, with an illuminated with white light, logo of the company was laser cut, which is in fact a symbol of iron.

˻ ˻ FEATURES ˺ The Polish DAC offers as many as six digital inputs: AES/EBU, RCA, Toslink, two HDMI and USB. We can connect a TV to one of the HDMI inputs, equipped with an ARC return channel, and a file transport or CD to the other. This type of transports are offered by many companies from the Far East, but also by PS Audio. The USB input is unusual for this class of devices, because it features a USB-C type socket. The DAC decodes PCM and DSD signals and also offers an MQA decoder on all inputs.

In press materials, the manufacturer says that all inputs are "optimized for audio signals", and the USB input uses custom firmware:

• AES/EBU – PCM do 196 kHz, 24 bity, DoP 64,
• Toslink – PCM do 96 kHz, 24 bity,
• RCA – PCM do 196 kHz, 24 bity, DoP 64,
• USB-C – PCM do 768 kHz, 32 bity, DSD 256
• ARC – PCM do 196 kHz, 24 bity,
• I2S – PCM do 768 kHz, 32 bity, DSD 256 (compatible with PS Audio).

In addition to the digital inputs, there is also a stereo RCA analog input. There are two outputs with RCA or XLR sockets - the device is a fully balanced design.

˻ ˻ CONTROLS ˺ Controlling the converter is extremely simple, easy and pleasant - I say this from experience and it is not a fragment of the Ferrum advertising leaflet. The basis is a large, color touchscreen. There you will find information about the selected source, the type of digital signal and its parameters. And from the bargraph you can read the volume level. Because the Wandla is not only a DAC, but also a preamplifier. The volume adjustment can be performed in the digital domain - it is part of the ESS Sabre ES9038PRO chip, which was used - or in analog, in an integrated resistor ladder. The volume is controlled by a large volume knob or a nice metal remote control.

From the menu level, we can set the brightness of individual lighting elements, and also choose whether they will react to the brightness of the external light. There we will also select whether the analog output deliver fixed or adjustable signal level and select a digital filter. Interestingly, Ferrum refers to this section as "upsampling". The first two, "Gauss" and apodizing, are those prepared by Jussi Laako, and the next three were selected from the ESS lineup (their standard D/A chips feature seven filters to choose from) - they are linear phase, "minimum-phase" and, again, apodizing.

˻ ˻ TECHNOLOGY ˺ As Marcin Hamerla said, the main components of the DAC were programmed in-house by HEM engineers, the parent company of the Ferrum brand, except for Jussi Laako, employed especially for this project, the creator of HQPlayer, a software file player sold under the Signalist brand.

Last year, during the Munich High End Show, Marcin showed the Heart, an ARM chip in which many different functions were integrated, and which can be the basis of any D/A converter. Wandla is the first device it was applied in. This is where the Laako digital filters and the MQA decoder/renderer reside. This chip is to replace five other chips that have been used so far.

Information about the I/U converter is also very important. This is a system that converts the current signal available at the output of the converter into a voltage signal, which the output circuits work with and which is sent outside. This is an extremely difficult element of the D/A converter (I mean the device), which is why every good company prepares its own.

˻ ˻ POWER SUPPLY ˺ The Ferrum company started with the Hypsos power supply. All its products are prepared to be powered in this way. On the back of the Wandla DAC, next to the classic power inlet, we can also find a high-quality, screwed socket for a four-core Ferrum Power Link (FPL) cable with a 4T voltage sensing system, which allows for very precise matching of both devices. By default, however, Wandla is powered from an external switched-mode power supply, similar to the one we get with a laptop.

▌ SOUND

˻ HOW WE LISTENED ˺ The WANDLA DAC was tested in the HIGH FIDELITY reference system and compared to the D/A section of the Ayon Audio CD-35 HF Edition SACD player, which also worked as a transport, and to the Mytek Brooklyn Bridge file player. As usual, I was most interested in how the DAC deals with the signal from CDs, and this time it was equally important how it decodes the MQA signal, so I also used MQA-CDs.

Ayon’s digital output and the DAC's RCA input were connected with the RCA→RCA Acrolink Mexcel 7N-DA6100 II cable, and the DAC (and then the Hypsos power supply - see text) was powered using Harmonix X-DC350M2R Improved-Version cable. Ferrum stood on the top shelf of the Finite Elemente Master Reference Pagode Edition Mk II rack on its own feet. In my system I use RCA cables and this is how the DAC was tested primarily. It was connected to the Ayon Audio Spheris III preamplifier using Crystal Cable Absolute Dream cables. However, I listened to its XLR output using its volume control separately - the balanced signal was led directly to the XLR outputs of the Soulution 710 amplifier.

Recordings used for the test | a selection

⸜ THE ROLLING STONES, Exile on Main St., Atlantic/Universal Music Company (Japan) UICY-40001, Platinum SHM-CD (1972/2013).
⸜ JIMMY SMITH & WES MONTGOMERY, Jimmy & Wes. The Dynamic Duo, Verve Records/Universal Classic & Jazz UCCU-9240, „Universal Jazz The Best 1500 ⸜ No. 40”, CD (1966/2006).
⸜ MARK HOLLIS, Mark Hollis, Polydor 537 688-2, CD (1988).
⸜ DANIEL VARSANO, Satie, kopia z niewydanej taśmy analogowej z archiwum Fleminga E. Rasmussena, Gryphon Master CD-R.
⸜ MARTA ZALEWSKA, Marta Zalewska, Polskie Radio PRCD 2240, CD (2021).
⸜ KIM ANDRÉ ARNESEN, Tuvayhun. Beatitudes For A Wounded World, wyk. Nidarosdomens Jentekor & Trondheimsolistene, 2L 2L-171-SABD, Pure Blu-ray + SACD/MQA-CD (2022).
⸜ VARIOUS, Jazz Hi-Res CD Sampler, Universal UCCU-40126/7, CD + MQA-CD (2018).
⸜ VARIOUS, 2L MQA-CD, 2L 2L-MQA-CD-2021, MQA-CD (2021).

WE'VE BEEN TALKING ABOUT IT FOR A LONG TIME, but with devices like the Wandla, the same thought suddenly "pops" out of the memory compartment where I put it. I'm thinking about the sound of tube and solid-state devices becoming more and more similar. It is obvious that each of these techniques has its advantages and disadvantages, and it is equally clear that each of them has its supporters and opponents. However, I think that it must be objectively admitted that semiconductors now "sound" much better than they used to, and that in a blind test it would be difficult to distinguish them from tubes.

The tested DAC offered a very saturated and internally complex sound. There was no desire to selectively "push" sounds, simulating resolution, but there was a real resolution. The tonality was very well set, maybe not as low as in the D/A section of the Ayon Audio player, featuring, let me remind you, a tube output, but really low.

That's why WES MONTGOMERY's guitar from Jimmy & Wes. The Dynamic Duo had a very nice, soft and full "body". At the same time, it did not lose its clear attack - it is, after all, a guitar with a tube amp. The Hammond B-3 of the second leader, that is JIMMY SMITH, sounded in an open, slightly penetrating way when played in high registers, and warm and soft when played underneath the guitar as its background. It was really a very good presentation of this album.

So the timbre was very well set, very natural, there was also a high resolution. But what will probably appeal even more is the tonality itself, but combined with very high dynamics. The album in question begins with an introduction in which part of the brass section plays on the left, it vibrates in the middle, and the percussion is on the right. They dialogue with each other and exchange leadership. The Polish DAC showed their "game" right away, because it perfectly sensed the differences in energy - stronger when a given section came to the fore, and slightly less so when it receded. Which showed that Wandla has a unique ability to play energetic sound and is able to manage this energy.

The DAC has a slightly stronger upper midrange than the reference system, but it has more body than with the Mytek Brooklyn Bridge file player. THE ROLLING STONES from Exile on Main St., in the version released in 2013 on the Platinum SHM-CD, had an energetic "flow", but without brightening the treble. This recording is characterized by quite high compression and is quite dark, in the sense that there is not much information in the treble. Also Jagger's voice is cut off top and bottom. It's a blues album, that's why it's all about rhythm and harmony.

The Wandla managed to stop the excessive brightening very efficiently, but also did not darken the image, so to speak. Its sound is open, stronger than in the reference player, that's for sure. The energy of the midrange and treble is high. Thanks to maintaining the right proportions, the timbre is not distorted here. It is a rich and strong timbre. The DAC is an excellent energy transmitter, but the energy is supported by the filling, not the attack itself.

OPENING THE ONLY solo album by MARK HOLLIS, the leader of the Talk Talk band, the introduction with piano and vocals was played extremely emotionally. The instrument, recorded from a certain distance, so playing mainly in the midrange, and placed close in front of the Hollis microphone - together it gave a minimalist, i.e. very, very credible image. When, in turn, in the second track Watersheed in the right channel you can hear the guitar, it has incredible energy and is a bit warm at the same time.

So the Polish DAC sounds the way only tube devices should sound a few years ago. It plays, to a large extent, as if we were listening to vinyl. In the sense that it is a high-octane sound with saturated colors. Also the bass has "power" and is fast. Its lowest part does not go as low as in Ayon, but it is much better than from Brooklyn.

The soundstage is very deep, and its differentiation is exceptionally good. Stereophony is not extended far to the left and right, and this is because the device focuses on direct sound. Reverbs, reflections and other spatial effects are present. But you can also hear that the DAC focuses on what the instrument is, and not its acoustic environment. This is why we have such high energy and such a good view of the whole.

˻ ˻ MQA-CD ˺ MQA has had some bad press lately. Many sound engineers, including "our" Paweł Bemol Ładniak, consider it a humbug and a cash grab (more → HERE ⸜ PL). Others such as Dirk Sommer and journalists at hifistatement.net, as well as some editors of other magazines, including John Atkinson, former editor of Stereophile magazine, are strongly in favor of this solution. Originally developed for file transfer over the Internet, it has also found its application in the physical world, in the form of MQA-CDs (more → HERE).

In Japan, discs of this type are released by Universal Music Japan, in Europe by Swedish 2L, and in the USA by, among others, Impex, either as MQA-CDs or as hybrid SACDs with a CD layer encoded in MQA. It usually has DXD parameters, i.e. a resolution of 24 bits, 352.8 kHz. It is a lossy encoder, but - as I said - it has its advantages. Among them, the most important is the ability to correct time errors ("time blurring"), also "backwards", i.e. those resulting from the coding of an analog signal into a digital one.

The Wandla decodes the MQA signal from all inputs, which allows it to play this type of discs from the CD transport. And this is exactly how MQA can really appeal to you. While FLAC files usually sound better than MQA, with physical discs we get a sound in which the instruments have a clear attack, are clearly arranged in space, and at the same time are dense and strong "in themselves", so to speak. The level of sound achievable from CDs and SACDs played on the Ayon player is quite absorbing, but let's remember about the huge price difference between these sources. Taking this into account, let's say that if I had the Polish DAC, he would necessarily buy a CD transport for it, since it sounds great with Compact Discs, it will sound even better with MQA-CDs.

˻ ˻ FILTERS ˺ The differences between HQ Gauss and apodizing filters are not big. However, they will help you adjust the DAC to your preferences. The first one results in a more direct "here and now" sound. The presentation is still saturated and has great energy. It also has a stronger treble, or at least its attack. The apodizing filter sounds a bit more distant, with better differentiated distances between the instruments.

The linear phase filter, or ESS filter, sounds yet differently. It sounds darker than the two previous ones, and the upper midrange is less accentuated with it. The "Minimum Phase", in turn, extinguishes some energy, but also smooths the treble. Bass has a softer attack with it and is not as precise. The ESS apodizing filter is more similar in tonality and energy to its HQ counterpart. Usually this is my favorite filter. Here, however, it is a bit too aggressive, as if the energy recovered by the lack of pre-impulse ringing was taking some sounds out of the mix.

So I was surprised to find that I liked the filter described as HQ Gauss the most. It had, in my opinion, the best set timbre, and was incredibly energetic at the same time. And it was with it that the sound was truly three-dimensional, not only on stage, but also within a given instrument. Differentiation was also the nicest with it.

˻ ˻ POWER SUPPLY ˺ Changing the power supply from impulse to linear, preferably from the top shelf, changes the sound of the Wandla more than changing the digital filters. This is a really important and desirable upgrade.

The Ferrum Hypsos power supply, which I received together with Wandla, did not yet have the voltage preset loaded for this device. An update of its software will probably be available soon - it is performed via the USB port. However, since the voltage and current requirements of the tested converter are identical to those of the Erco converter, I selected this device in the menu, and then increased the supply voltage from the nominal 24 V DC to 28 V DC.

Wandla listened to in this way sounded much denser and lower. The energy remained, and so did the above-average ability to differentiate dynamics. The timbre darkened - in a way that we expect from a high-end device. Because in this configuration it is a real high-end. With beautiful timbres, dynamics and a realistic soundstage. Subsequent discs listened to in this way showed another dimension in each of these elements. They were more immersive and I really enjoyed that.

▌ Summary

Wandla with the switched-mode power supply, with which we buy it, is great, it is a device that deserves the RED FINGERPRINT award. But with the Hypsos it is a top-shelf system, which cannot be awarded less than the GOLD FINGERPRINT.

▌ DESIGN

The FERRUM WANDLA DAC features a housing identical to the that of previous devices of this company. It's a steel chassis with a thin aluminum front baffle. The device rests on small rubber feet. The nice XLR and RCA connectors come from Neutrik, with large conductive elements, Teflon dielectric, and they are fully gold-plated. The DC power inlet, where we plug the DC power cable in, is exceptionally good even compared to the other connectors. Both it and the plugs of the power cable come from WEiPU (Series 12). I will add that the socket has a bayonet latch.

Almost the entire circuit has been assembled on a single, multi-layer PCB, occupying the entire housing of the converter. The exception is the Heart, a compute "brain" board with filters, control circuit, etc., this module has its own smaller PCB. The ST Microelectronics ARM chip works here, replacing - as the manufacturer says - as many as five previously used chips. It was programmed by HEM in-house. The signal from the S/PDIF inputs goes to the Burr-Brown DIX41921 digital receiver, and from the USB directly to the ARM chip in which the algorithms are stored that allow the conversion of the USB signal into a "understandable" one for the DAC. This section is already known from the Erco DAC, but here it functions as a standalone unit.

The DAC chip is the ESS Sabre ES9038PRO, and after it there is the proprietary I/U converter chip. It uses four integrated circuits per channel, mainly Burr-Brown’s. The next step is two, one per channel, great-looking integrated resistor ladders, MUSES72323V-TE1 from Nisshinbo Micro Devices, which are its flagship products. The analog input is buffered in the LT and Burr-Brown circuits. The volume control section is bypassed by activating large, hermetic relays, also visible on the output of the device. On the side, there is a a complex power supply, additionally stabilizing the power supply. ●

▌ Technical specifications (according to the manufacturer):

Digital inputs:
• AES/EBU – PCM up to 196 kHz, 24 bits, DoP 64,
• Toslink – PCM up to 96 kHz, 24 bits,
• RCA – PCM up to 196 kHz, 24 bits, DoP 64,
• USB-C – PCM up to 768 kHz, 32 bits, DSD 256
• ARC – PCM up to 196 kHz, 24 bits,
• I2S – PCM up to 768 kHz, 32 bits, DSD 256 (compatible with PS Audio).
MQA: decoder & renderer (all inputs)

Analog input: RCA
Analog input Vmax: 9,5 V RMS (recommended 2-3.5 V RMS)
Input impedance: 47 kΩ
Output level (0 dBFS, 1 kHz):
• XLR – 9.3 V RMS
• RCA – 4.65 V RMS
Frequency range: 10 Hz – 200 kHz (+/- 0.1 dB)
THD:
• DAC -121 dB (0.00009%); THD+N: -115 dB (unweighted)
• analog input -123 dB (2 V RM)
Dynamic range: 127 dB
Output impedance: XLR – 44 Ω | RCA – 22 Ω

Power consumption: 10 W (idle), 15 W (max)
Dimensions: 217.5 x 206,5 x 50 mm (W x H. x D; without knob, feet and sockets)
Weight: 1.8 kg