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DACs — Concert Fidelity DAC-040Mk2 ULT1
Description, images, technical data and specifications
Concert Fidelity DAC-040Mk2 ULT1
Image source — © Concert Fidelity
The DAC-040Mk2 ULT1 is the two-input version of the valve-buffered DAC-040Mk2 from Concert Fidelity, hand built in Japan by founder Masataka Tsuda. It pairs the same Philips 16-bit non-oversampling chip found in the NOS model with both a USB port and a coaxial digital input. Tsuda began building valve amplifiers at 10, held a ham radio licence at 14 and spent 12 years at his father's precision machining firm before working in semiconductor and measuring instrument trading.
Key specs that matter
Digital connections comprise one USB 2.0 Type B socket and one 75 ohm S/PDIF coaxial input, supplied as a BNC connector or, as an option, an RCA jack. USB data is converted by a module that outputs I2S at 16 bits and 32, 44.1 or 48 kHz, followed by a digital isolator. The 16-bit Philips converter runs without oversampling, so samples reach the chip at their original rate without upsampling. The analogue output stage uses two 12AU7, also sold as ECC82, for amplification, plus one rectifier valve that may be a 6V4/EZ80 or a 6CA4/EZ81. A selector gives 6 or 12 dB of gain in the standard build, or 0 and 6 dB when the lower-gain option is specified. Analogue output is a single stereo pair on RCA sockets. The chassis is 450 by 310 mm in plan and 100 mm tall, and the net mass is 12 kg.
Engineering and use context
The digital isolator separates the USB receiver electrically from the converter stage, and a valve rectifier feeds the tube buffer. Concert Fidelity treats the DAC-040Mk2 as a build-to-specification platform, and Tsuda's approach, which he calls Direct Signal Path Technology, aims to cut the time the signal spends inside the circuit. Access to the gain tubes from outside the rear panel invites the owner to try different makes. No valves come in the box. Each unit is fitted with a mains transformer for its destination country, and running it on any other mains voltage falls outside the maker's guarantee.
Pairing
Having two inputs lets one ULT1 serve a CD transport on the coaxial socket and a computer on USB at the same time. The single-ended output suits the brand's CF-080LSX4 line stage, and the ZL-120FX2 monoblocks, which reach rated power from a 2 V input, complete an all-Concert Fidelity chain. Owners of an amplifier with high input sensitivity can order the 0 dB setting.
Alternatives
For DSD files and PCM beyond 48 kHz, the Concert Fidelity DAC-040Mk2 ULT2 swaps the Philips part for an AKM 32-bit converter in the same case.
Key specs that matter
Digital connections comprise one USB 2.0 Type B socket and one 75 ohm S/PDIF coaxial input, supplied as a BNC connector or, as an option, an RCA jack. USB data is converted by a module that outputs I2S at 16 bits and 32, 44.1 or 48 kHz, followed by a digital isolator. The 16-bit Philips converter runs without oversampling, so samples reach the chip at their original rate without upsampling. The analogue output stage uses two 12AU7, also sold as ECC82, for amplification, plus one rectifier valve that may be a 6V4/EZ80 or a 6CA4/EZ81. A selector gives 6 or 12 dB of gain in the standard build, or 0 and 6 dB when the lower-gain option is specified. Analogue output is a single stereo pair on RCA sockets. The chassis is 450 by 310 mm in plan and 100 mm tall, and the net mass is 12 kg.
Engineering and use context
The digital isolator separates the USB receiver electrically from the converter stage, and a valve rectifier feeds the tube buffer. Concert Fidelity treats the DAC-040Mk2 as a build-to-specification platform, and Tsuda's approach, which he calls Direct Signal Path Technology, aims to cut the time the signal spends inside the circuit. Access to the gain tubes from outside the rear panel invites the owner to try different makes. No valves come in the box. Each unit is fitted with a mains transformer for its destination country, and running it on any other mains voltage falls outside the maker's guarantee.
Pairing
Having two inputs lets one ULT1 serve a CD transport on the coaxial socket and a computer on USB at the same time. The single-ended output suits the brand's CF-080LSX4 line stage, and the ZL-120FX2 monoblocks, which reach rated power from a 2 V input, complete an all-Concert Fidelity chain. Owners of an amplifier with high input sensitivity can order the 0 dB setting.
Alternatives
For DSD files and PCM beyond 48 kHz, the Concert Fidelity DAC-040Mk2 ULT2 swaps the Philips part for an AKM 32-bit converter in the same case.
Specifications
Model name
DAC-040Mk2 ULT1
Conversion type
N/A
Engine
N/A
DSD compatability
N/A
Parameters
up to 16 bit / 48 kHz
Frequency response low +/- 3dB (Hz)
N/A
Frequency response high +/- 3dB (Hz)
N/A
Gain (dBu)
6dB and 12dB(Std) or 0db and 6db(Option)
Output Level (balanced) (V)
N/A
Output Level (single-ended) (V)
N/A
Input Impedance (balanced) (Ω)
N/A
Input Impedance (single-ended) (Ω)
N/A
Output Impedance (balanced) (Ω)
N/A
Output Impedance (single-ended) (Ω)
N/A
Analog outputs
N/A
Signal to Noise Ratio (dB)
N/A
Total Harmonic Distortion + Noise (% at 22 kHz)
N/A
Dimensions (mm)
450 X 100 X 310
Weight (kg)
12
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