DACO is a digital-to-analog converter with a tube output stage, designed and manufactured in Poland by IGS Audio. The digital section is built around a dual AK4493SEQ conversion chip (AKM) – among the more highly regarded DAC silicon in the hi-fi segment – managed by an AK4118 digital receiver (AKM) and a QCC5125 Bluetooth receiver (Qualcomm). After conversion, the analog signal passes into a tube output buffer built around a pair of NOS military-grade 6N6P-VI valves (alternatively 6N30P), operating without global negative feedback. The buffer is transformer-balanced at both input and output with full galvanic isolation from the output stage. All transformers are custom-designed and supplied by UTM Industry. A linear power supply with a GZ34 tube rectifier and ultra-low-noise filtering stabilises the voltage rails feeding the tube and analog stages.
Digital input architecture – what DACO accepts and at what resolution
DACO accommodates five types of digital input: AES/EBU, S/PDIF, ADAT, USB, and Bluetooth. The USB input handles PCM up to 384 kHz and DSD64, DSD128, DSD256, and DSD512 – the full range of hi-res formats available from streaming services and local digital libraries. AES/EBU, S/PDIF, and ADAT inputs support PCM up to 192 kHz. Bluetooth via the QCC5125 Qualcomm chip covers up to 96 kHz, which in practice handles LDAC hi-res streaming. A 2-inch OLED display on the front panel shows the active input and current sample rate; an input selector and IR receiver window add remote control operation. The 380×290 mm enclosure is machined from 3 mm aluminium CNC and weighs 6 kg.
Tube output buffer and analog performance
The 6N6P-VI tube is specified for exceptionally linear operation and low self-noise – in the context of a DAC output stage, this translates to wide soundstage, micro-dynamic resolution, and the absence of the flattening effect common in cheaper solid-state output stages. Designing without global NFB preserves the full sonic character of the tubes while maintaining distortion at THD below 0.03% at 1 kHz and 0 dBFS. Frequency response extends from 8 Hz to 80 kHz (±1 dB); dynamic range measures 112 dB per AES17. RCA output delivers 2.5 V RMS unbalanced; balanced XLR output provides 5 V RMS. Power consumption is 45 W.
KEY FEATURES
- Dual AK4493SEQ DAC (AKM) + AK4118 digital receiver (AKM)
- Tube output buffer: 2× 6N6P-VI or 6N30P NOS military-grade
- No global negative feedback
- Transformer-balanced tube buffer I/O with galvanic isolation
- Linear power supply with GZ34 tube rectifier, ultra-low-noise filtering
- Inputs: AES/EBU, S/PDIF, ADAT, USB, Bluetooth (QCC5125 Qualcomm)
- USB: PCM up to 384 kHz, DSD64/128/256/512
- Outputs: RCA 2.5 V RMS, XLR 5 V RMS (balanced)
- 2-inch OLED display, IR remote control
- Frequency response: 8 Hz – 80 kHz ±1 dB
- Designed and manufactured in Poland
TECHNICAL SPECIFICATIONS
- Type: digital-to-analog converter with tube output buffer
- DAC chips: 2× AK4493SEQ (AKM, dual)
- Digital receiver: AK4118 (AKM)
- Bluetooth receiver: QCC5125 (Qualcomm)
- Buffer tubes: 2× 6N6P-VI or 6N30P (NOS military-grade)
- Power supply rectifier: GZ34 (tube)
- THD: below 0.03% (1 kHz, 0 dBFS)
- Dynamic range: 112 dB (AES17)
- Frequency response: 8 Hz – 80 kHz ±1 dB
- USB input: PCM 44.1–384 kHz, DSD64/128/256/512
- AES/EBU, S/PDIF, ADAT inputs: PCM 44.1–192 kHz
- Bluetooth: PCM 44.1–96 kHz
- RCA output: 2.5 V RMS (unbalanced)
- XLR output: 5 V RMS (balanced)
- Power consumption: 45 W
- Enclosure: 3 mm CNC aluminium, 380 × 290 mm
- Weight: 6 kg
- Manufactured in Poland
