Ferrum HYPSOS - Part 1

I've been looking forward to this test for over a year. During the development of the HYPSOS hybrid power supply, the first-ever Ferrum product, I was in constant contact with the developers. I was able to test an HYPSOS with beta firmware back in September. However, the impressive listening experience didn't make the wait any easier.

So, just before the turn of the year, the time has finally come. The Hifistatement editorial team received two copies of the new Ferrum HYPSOS. I am very pleased that one of the two hybrid power supplies has landed with me. After the first impression on the last development metres, I simply didn't want to miss out on a test. A second power supply unit was delivered to Dirk Sommer. In this article you will read both his and my verdict on the HYPSOS. It's no secret that Dirk's stereo system puts mine in the shade by a long way. But that's precisely why it's interesting to examine the PSU in two completely different set ups and on devices in different price categories. We also arranged a Skype interview with Marcin Hamerla, CEO of HEM and founder of Ferrum.

Marcin Hamerla and his team at HEM are not unknown in the hi-fi scene. The company based near Warsaw is the manufacturer of Mytek. The Mytek's converters are very much appreciated by the editorial staff. For example, a Mytek Brooklyn DAC + is permanently playing in my chain. A Brooklyn Bridge, a Brooklyn AMP, and a Liberty DAC were also on test. A Manhattan DAC II plays in Dirk Sommer's living room chain. By producing Mytek devices, HEM has accumulated a wealth of experience that is not limited to converters. As a result, the creation of Ferrum was only a matter of time. HEM's new, proprietary product line offers room for innovation and fresh ideas. The first of its kind is Ferrum's HYPSOS hybrid power supply. It is supposed to combine the best features of a switching power supply and a linear power supply. It is an ambitious goal. After all, a purely linear power supply is the optimum for hi-fi enthusiasts, at least so far. Whether this will change from now on, you can find out in this article. Variable output voltages of five to 30 volts at up to six amps or 60 watts speak for themselves. But how exactly switching and linear power supply come together in the HYPSOS and what other special functions it offers, we will let Marcin and the head of the development department explain in an interview later.

Ferrum, the eponymous element iron is not only found in the product logo, which contains the element abbreviation for iron from the periodic table, but also on the front of the power supply unit. The backlit logo is framed by a rust-red iron plate and unmistakably marks the HYPSOS as a Ferrum product. Marcin Hamerla's father worked as an ironsmith. Moreover, the Polish composer and piano virtuoso Chopinwas born not far from Warsaw in the small village of Żelazowa Wola. Żelazo means iron in Polish. The name Ferrum was therefore very obvious. It simultaneously transports a personal memory and a reference to an outstanding composer, thus to musicality itself. With the logo and iron element on the front, the power supply is a real design piece and not just a block that one would prefer to hide behind the rack. With its dimensions of around 22 by 20 by 5 centimeters, it has an identical footprint to my Brooklyn DAC +. Therefore, this invites you to place both devices on top of each other. In terms of temperature, this should not be a problem. I did not notice any disturbing interference in the converter. The front also has a centrally placed display and a rotary encoder on the right-hand side. On the back, there is the power connection, a USB socket for firmware updates, and a 3.5-millimeter jack as a trigger input. In addition to a quick start guide, the scope of delivery includes a power cord and two DC cables for connecting the power supply unit to components: one with a 2.5-millimeter plug and a second with a 2.1-millimeter plug. Both cables are a good 50 centimeters long and other configurations are available upon request. The cables stand out as unusual in a positive sense. You do not expect the usual thin DC cable with cold-pressed plugs, but a rather thick cable with four wires and a solid, self-locking plug for connection to the power supply unit itself. The connection cables perfectly round off the extremely high-quality haptic and optical overall impression of the HYPSOS.

When switching on the power supply for the first time, the desired voltage and polarity must be selected. For many units, the correct settings are already stored. All currently pre-configured device profiles can be found at the end of the article after the manufacturer's specifications. The list can be continuously extended by the Ferrum team by means of firmware updates. So please feel free to inform the team about your device request. Of course, you can also configure the HYPSOS manually if your device is not in the list. All you have to do is determine and set the required voltage and polarity. This information can usually be found on the back of the device or in the manual. If you are unsure, the manufacturer of your device or Ferrum will certainly help. One should not forget that an incorrect setting could destroy the device. That's why HYPSOS asks for each setting again and even offers a ten-second time window before the voltage is released, so that you can cancel the process if necessary. A profile is already stored for my Brooklyn DAC +, which I select by pressing the rotary encoder. The stored voltage and polarity are shown to me for confirmation. Only then does the HYPSOS release the voltage.

In the Skype interview, Marcin Hamerla was joined by Paweł Gorgoń, the head of the research and development department at HEM. Both answered a few questions about the creation of Ferrum and the HYPSOS. My questions about the technical details, on the other hand, were answered in advance by developer Maksymilian Matuszak via email.

Hifistatement: How did the idea to launch your own brand with Ferrum come about?
Marcin: HEM has been around for about 22 years now and we have about 25 people working for us. We have always worked with Mytek, but we also manufacture many OEM products for industrial audio applications. I am very lucky to have met many good and talented people on my way with HEM. Paweł, for example, originally begged me to hire him. It has since been reversed and I would beg him to work for me. He joined the company as a student and has proven to be very talented. He is now the head of the research and development department at HEM and our R&D brain. He is great with electronics, a good programmer, and very good at organizing employees.
Paweł: I would like to interject that the best thing about HEM is teamwork. I can't do everything on my own, so I'm happy to have a talented team of electronics specialists and programmers. Without them, the HYPSOS would not have been possible.
Marcin: A few years ago, the engineering team grew. Most of them are very young and audio enthusiasts. Sometimes they are real show-offs, hungry for success, and often unconventional. With a traditional brand like Mytek, there is not always room for this. That is why Ferrum is like a playground for my engineers and as a result, the HYPSOS was created. The idea for Ferrum is around two years old. The intensive brand development began a year ago. However, the development process of the HYPSOS only took about half a year. That has a lot to do with the high standard of the organization at HEM. The team and its communication and planning are very effective. This aspect is many times underestimated. It often represented the core difficulty of product development. The idea of the brand name Ferrum has different origins. One of them lies in the time of the Teuton tribes. The Vandals lived in what is now Poland at that time. There was a Vandal iron mine near my house. Even today you still need a permit to dig in the neighborhood, as relics from that time can be found everywhere. That's why there is an archaeological museum very close by, which we supported. This is one of the reasons for the name Ferrum.

Hifistatement: Were all HEM employees involved in the development of the HYPSOS or is there a core team?
Marcin: The development department, consisting of seven people, is of course largely responsible for HYPSOS. As I said, Paweł is the development manager and Max developed most of the entire HYPSOS hardware. He's also a good programmer but prefers to work with metal. Nevertheless, Ferrum would be impossible without the production, sales, and distribution departments. Every department and every employee is important.
Pawel: Max is surprisingly young in his early twenties but is an outstanding engineer.
Marcin: That's right. Family tradition. Even his father is a good engineer, and his son is even better.

Hifistatement: Is there a function or a characteristic of the HYPSOS that you are particularly proud of?
Pawel: I am simply very satisfied with the overall product.
Marcin: For me, the most important thing is the solid basic construction of the power supply. A special feature of the HYPSOS is the use of a lot of software compared to commercially available power supplies. Many parameters can be influenced in this way. Due to the solid basic construction, we were finally able to use software to exceed the originally intended output power. The finished HYPSOS delivers a continuous output of 80 watts instead of the planned 60 watts. The pulse power is even 200 watts. We still have to adjust the technical data on our website. (Editor's note: In the manufacturer's information, we accordingly state the value previously stated on the website).

When I asked my final question about the future of Ferrum and new products, Marcin kept a low profile. There are many ideas and a good team on top of that. So I would be very surprised if the HYPSOS was the last Ferrum product. Now for the technical details that Max explained via email.

Hifistatement: The HYPSOS combines the technology of a switched-mode power supply with that of a linear power supply. How do these two types work together in HYPSOS and what are the advantages of a hybrid power supply unit?
Max: We decided on a hybrid design for the HYPSOS because we wanted to keep the residual ripple and noise at the output low, but still wanted to have a large output voltage range. A linear regulator is the best to keep the noise down, but with the HYPSOS output voltage range the heat sink would be the size of the moon so we had to find another way. That's why we decided to keep the linear regulator but put an efficient stage with a switching regulator in front of our discrete low-drop-out voltage regulator (LDO), which keeps the voltage at the LDO constant and minimizes power dissipation. This allowed us to keep the power loss low, but the residual ripple at the output is greatly reduced because we are still using a linear regulator. As I said, it suppresses the residual ripple. Besides, we use a two-stage LC filter after the switching converter to further suppress the noise to smooth the voltage at the output of the regulator. All in all, we have succeeded in developing a power supply unit that has a lower power loss than a linear regulator. But we still have a fast transient response in switching current, low noise, and low ripple, as is the case with the linear regulator. This wouldn't be possible if we were just using a switching regulator.

Hifistatement: 4T Sensing Design and Spread Spectrum Mode are two special functions of the power supply. Please briefly explain to our readers how they work and tthe resulting effect on audio reproduction.
Max: 4 Terminal Sensing Design (4TSD) is a feature that greatly reduces the influence of the cable resistance on the voltage at the output of the cable. Most external power supplies measure their output voltage directly at their output, but not at the load, at the end of the cable. Therefore, the current supplied by the power supply is what causes the voltage drop across resistance of the cable. So, if the current supplied by the power supply is high, the voltage seen by the load may be lower than the voltage at the output of the power supply. For this reason, the HYPSOS is equipped with 4TSD, which measures the voltage directly at the output of the cable and not at the output of the power supply, so that the effect of the voltage drop on the cable is minimized. We use a 4-wire cable, with two wires for the power supply and the other two wires for voltage measurement. In this way, the high current only flows through the two wires that are intended for the power supply. Almost no current flows in the cores that are intended for voltage measurement so that there is no voltage drop in these measuring cables and the influence of the cable resistance is reduced to a minimum. This is very important as changing the supply current has much less impact on the output voltage and causes much less distortion when the 4TSD is activated. The spread spectrum mode is a possibility to reduce the high-frequency emission caused by the switching regulator. It modulates the switching frequency of the controller, which lowers the level of the main switching frequency ripple and its harmonics. As a result, there is less noise from the power supply that some amplifiers might modulate back into the audible range.

After the extensive interview and report on the functions and features of the power supply unit, we unfortunately have to keep you in suspense for a while. The listening report will follow soon. I hope you are no less in joyful anticipation than I was while waiting for the arrival of the HYPSOS for this review.

HYPSOS' Presets (12th of January 2021):
432 EVO Essence, Alpha Design Labs: GT40alpha, Stratos, Apogee Mini DAC, Arcam: airDAC, irDAC, irDAC II, rBlink, rDAC, rHead, rPlay, SonLink DAC, Audioengine: D2 24-Bit Wireless DAC, D2D Add-On for D2, Bel Canto: DAC1.5, CD2 CD Player 24/96, FM1 FM Tuner, Beresford CAIMAN SEG TC-7535, Cambridge Audio: DacMagic PLUS, DacMagic 100, iD100 Dock, Chord: Hugo M Scaler, Hugo TT2, Qutest, Creek: OBH-11 Mk2, OBH-15 Mk2, OBH-21 Mk2, Denon DA-300USB, Dynavector: P75 Mk3, P75 Mk4, Elac Discovery Music Server, exaSound: e22 DSD256 DAC, e28 DSD256 m-ch, Playpoint, e12 DAC, e20 DAC Mk III, FiiO QOGIR-E09K, Fram MIDI 120, Graham Slee: Accession, Elevator EXP, Reflex C, Reflex M, Revelation, Solo, iFi Audio: Pro iCan, iTube, iUSBPower, iCAN SE, iPhono2, iPhono, Pro DSD DAC, ZEN MINI, innuOS Wave Music, M2TECH: Marley MK2, Evo DAC Two, Evo DAC Two Plus, Young MK3, hiFace EVO, Martin Logan: ElectroMotion ESL, ElectroMotion ESL C9, ElectroMotion ESL X, ElectroMotion Theos, McIntosh: MB50, MS500, Melco: N100, S100, D100, E100, Meridian Audio: Media Core 200, Audio Core 200, Meridian Prime, Moon: 180 MiND Streamer, MOON 110LP, Mytek: Brooklyn Bridge, Brooklyn DAC+, Brooklyn DAC, Liberty DAC, Brooklyn ADC, Nuprime CDP-9, Paradigm PW LINK, Pathos Acoustics SRL: Aurium, Converto, Converto EVO, Ripstreamer PLAYER 64BITS ROON, RME -Audio Solutions: ADI-2, ADI-2 PRO FS, Roon Nucleus, Sonore: microRendu, ultraRendu, ultraDigital, SOtM: sHP-100, sMS-100, sMS-1000 A/D/U, sMS-200-ultra, sMS-200-ultra Neo, sMS-200, dx-USB HD, sDP-1000 DAC, Stax: SRM-212, SRM-252S, Uptone Audio REGEN, Wadia: di112, m330 media server, YULONG: A800 Class A, U100 USB, U18