Ferrum Audio ERCO Gen 2

The Ferrum Audio ERCO Gen 2 is the second generation of the Polish brand’s entry-level DAC/headphone amplifier. This version features a complete software overhaul and changes to the analog circuit. The device retains a compact desktop form factor and incorporates the in‑house‑developed SERCE digital platform, as well as a redesigned current‑to‑voltage conversion stage. It is offered with an upgrade program for owners of the original ERCO. This fully balanced DAC/headphone amplifier can be used for headphone listening or to drive active speakers.

Gen 2 upgrades: from software to circuitry

The second generation of the ERCO is more than a simple firmware update. The complete reprogramming involves implementing a new bootloader in the deep memory layers, going far beyond a conventional update.

Digital improvements

Since the ERCO’s digital hardware is very similar to that of the SERCE board, Ferrum was able to port the entire SERCE software stack to the ERCO. The Gen 2 unit therefore behaves exactly as if it were based on SERCE.

The HQ Apodizing digital filter has been added, identical to the one available on the WANDLA and preferred by its users. The ESS filters have been bypassed, including MQA processing for non‑MQA signals. This apodizing filter, developed by Jussi Laako of Signalyst (creator of the HQPlayer software), corrects certain artifacts introduced during recording or mastering, in particular intermodulation and intersample distortion.

Intermodulation and intersample distortion have been reduced, and output levels have been adjusted to comply with the Red Book standard on line output while achieving maximum output power on the headphone outputs.

Maximum resolution now reaches PCM 768 kHz and DSD 512, versus PCM 384 kHz and DSD 256 on the original model.

Analog improvements

After designing the new current‑to‑voltage (I/V) converter for the WANDLA, Ferrum acquired extensive experience in this field. The ESS DAC chip in the ERCO Gen 2 is a more compact version of the one used in the WANDLA (ES9028PRO vs ES9038PRO), but the original ERCO used an I/V converter designed in the “pre‑WANDLA” style.

The ERCO Gen 2 benefits from major updates to the I/V converter based on this expertise, delivering a more detailed, natural, and engaging sound signature.

Ferrum Power Link: optimized power with HYPSOS

The ERCO works properly straight out of the box with the supplied power adapter, but it is designed to go beyond this level when paired with the HYPSOS power supply via the proprietary Ferrum Power Link (FPL) cable.

Ferrum Power Link uses four conductors: two to deliver DC power and two to provide feedback, keeping the voltage perfectly stable at every moment. This technique eliminates the detrimental effects of cable resistance and improves transient response.

This connection allows HYPSOS to measure the voltage directly at the powered device rather than at the power supply output, ensuring more accurate regulation.

Design and ergonomics: functional simplicity

The ERCO Gen 2 retains the same dimensions as the HYPSOS, OOR, and the original ERCO: 21.7 × 20.6 × 5 cm. Weighing 1.8 kg, the unit remains stable on a desktop or when stacked on top of the HYPSOS.

The front panel has a minimalist layout: the backlit Ferrum logo (with adjustable brightness or switchable off), the 6.35 mm jack output, the balanced 4.4 mm output, the input selector with a status LED color‑coded to the detected format, the gain selector, and the analog volume potentiometer.

The indicator light next to the input selector changes color depending on the format and resolution of the digital file being played.

The rear panel houses the XLR and RCA outputs, the analog RCA inputs, the digital inputs (optical, coaxial, USB‑C), the bypass switch, the logo brightness control, a trigger output, and the two power inputs (5.5/2.5 mm DC connector and 4‑pin FPL).

Upgrade program for original ERCO owners

Ferrum has set up a program allowing owners of the original ERCO to upgrade their unit to Gen 2 specifications. This upgrade requires complete reprogramming and circuit modifications, which must be carried out by Ferrum‑certified technicians.

For ERCOS purchased after July 1, 2023, the upgrade is free of charge (excluding outbound shipping costs). For units acquired before this date. Owners must contact Ferrum via their website to obtain shipping instructions to their local distributor or to the European headquarters in Poland.

Technical specifications

Digital-to-analog conversion

• DAC chip: ESS Sabre ES9028PRO
• PCM sampling rates: 44.1 – 768 kHz
• DSD sampling rates: 2.8224 – 24.576 MHz (maximum DSD512)
• Maximum resolution: PCM up to 768 kHz / 32-bit, DSD up to 512 kHz
• High-quality digital filters optimized to fully exploit the DAC chip
• Enhanced SERCE DSP with oversampling and HQ apodizing digital filter by DDF
• Optimized current-to-voltage (I / V) conversion for better efficiency and increased linearity in the analog stage

Headphone amplification

• Fully balanced proprietary headphone amplifier
• Balanced headphone output power: 1.2 W into 300 Ω, 6.1 W into 50 Ω
• Single-ended headphone output power: 300 mW into 300 Ω, 1.7 W into 50 Ω
• Total harmonic distortion (THD) balanced headphone: < 0.00018% / -115 dB
• Total harmonic distortion (THD) single-ended headphone: < 0.00032% / -110 dB
• Input impedance: 47 kΩ
• Headphone output impedance: < 0.3 Ω
• Preamplifier output impedance: 22 – 44 Ω

Audio performance

• Dynamic range: 129 dB in analog, 117 dB in digital (A-weighted)
• Frequency response: 10 Hz – 30 kHz (± 0.05 dB), 10 Hz – 200 kHz (± 1 dB)
• Transparent sound signature to reduce listening fatigue
• Performance close to WANDLA with improved MQA rendering and digital processing

Connectivity

• Digital inputs
  • USB-C: PCM 768 kHz / 32-bit, DSD512, DoP256
  • Coaxial S / PDIF: PCM 24-bit / 192 kHz, DoP64
  • Optical S / PDIF: PCM 24-bit / 96 kHz, extendable to 192 kHz depending on cable
  • MQA support on all digital inputs
• Analog input
  • RCA: Red Book 2 V RMS recommended, PRO level supported
• Headphone outputs
  • Balanced 4.4 mm (TRRRS) jack
  • Single-ended 6.35 mm (TRS) jack
• Line outputs
  • Balanced XLR
  • Single-ended RCA

Power supply and physical dimensions

• Power consumption in standby: < 15 W
• Power supply: 100 – 240 VAC to 22 – 30 VDC
• Power connectors: 5.5 / 2.5 mm and 4-pin FPL
• Dimensions: 21.7 x 20.6 x 5 cm
• Weight: 1.8 kg

Exclusive technologies

• Fully balanced architecture: end-to-end balanced circuit, even after RCA inputs
• Ferrum Power Link (FPL) for stable power and feedback
• Hybrid discrete / IC design for the best possible analog quality
• Digital inputs optimized for USB-C, coaxial and optical S / PDIF

Key improvements

• Optimized current-to-voltage (I / V) conversion for better efficiency and increased linearity
• Enhanced SERCE DSP with oversampling and HQ apodizing digital filter
• Increased maximum resolution: PCM up to 768 kHz, DSD up to 512 kHz
• High-quality digital filters optimized for the DAC chip
• Performance close to WANDLA with improved MQA rendering and digital processing
• Fully symmetrical end-to-end circuit