Audio Database

Project D-1
Commentary

A D/A converter developed by combining the multi-bit inscription "TDA1541AS2 (double crown)" with the latest technology.

The Philips "TDA1541AS2" (Double Crown) is a real 16-bit dual DAC chip that guarantees 16-bit precision over a wide temperature range. To maximize the potential of this high-precision IC chip, we have developed an advanced original DSP, and by configuring an 8 fs digital filter, de-emphasis, invert circuit, and new feature "scaling", we have achieved excellent D/A conversion such as balance operation within one chip.

The I/V converter section and balance amplifier section are composed of Non-NFB circuits, eliminating the feedback loop to prevent digital noise from entering, and the adoption of Non-NFB power supply with temperature compensation greatly reduces internal transmission jitter caused by high-frequency characteristics and supply speed of the power supply section over the entire audible band.

To ensure that the D/A converter (/ A converter (16-bit) always has an appropriate full swing, it is equipped with a scaling controller that can change the scale of the signal (data) sent to the DAC input at the digital filter stage using the original DSP by + - 9 stages respectively (the value is determined unitarily in a normal digital filter IC).

The analog post-filter uses a second passive type with excellent phase characteristics and transient response.

The power supply consists of a 250 VA class large-capacity low-impedance wound power transformer, a high-speed 10A fast recovery diode, and a large number of parallel-connected low-magnification foil low-impedance chemi-cons.

For digital circuit boards, a four layer board with 35 micron surface and 70 micron inner layer copper foil is used. For analog / power circuit boards, a double-sided gold-plated board with a total thickness of 135 micron copper foil on one side is used.

It has a rigid and vibration-resistant chassis structure with a combination of a 3.2 mm thick copper-plated steel bottom chassis and side panels, rear panels and top panels made of extra-thick aluminum. The legs have a 3-point grounding with sintered alloy heavy insulators.

Equipped with seven digital inputs of three types : coaxial (BNC), optical, and balanced, and digital outputs of one each of coaxial and optical.
The digital output can be turned ON/OFF.

The sampling frequency is automatically switched to 32 khz, 44.1 khz and 48 khz.

The analog outputs include an XLR balanced output and a normal (positive phase) / inverted (negative phase) RCA unbalanced output.

Model Rating
Type D/A converter
Frequency characteristic 5 Hz ~ 15 kHz ± 0.5 dB (fs = 32 kHz)
5 Hz ~ 20 kHz ± 0.5 dB (fs = 44.1 kHz)
5 Hz ~ 22 kHz ± 0.5 dB (fs = 48 kHz)
Signal-to-noise ratio 100dB
Dynamic range 98 dB or more
Total harmonic distortion factor 0.005%(1kHz)
Channel separation 96dB(1kHz)
Digital input Coaxial : 0.5Vp-p/75 Ω
Optical:-19dBm
Balanced : 3-7Vp-p/110 Ω
Digital output Coaxial : 0.5Vp-p/75 Ω
Optical:-19dBm
Analog output Unbalanced : 2.5 Vrms
Balance : 5.0 Vrms
Pwer 100 VAC, 50Hz/60Hz
Power consumption 38W
Maximum external dimensions Width 440x Height 134x Depth 364 mm
Weight 17.0kg