ADC AK5572 boards are available again, in slightly modified version 1.2. Despite a rather long list of changes there are no differences in performance and no major changes in functionality.
Audio ADC with superb performance figures in a compact form factor. Suits audio recording kit, Hifi systems, or audio measurement applications.
- Up to 768 kHz / 32-bit audio
- Very high (measured) performance, typically:
- 121 dBA dynamic range / SNR (124 dBA in mono mode)
- -113 dB THD+N (-1 dBFS, 1 kHz)
- -117 dB THD (-8 dBFS, 1 kHz)
- -130 dB crosstalk (10 kHz)
- Balanced differential input
- Stereo or mono operation
- I2S output; Master or Slave
- HW configurable (supports I2C as well)
- Assembled boards available
- Simple balanced buffer with very high performance
- Noise level: -117 dBV A-weighted (v2.0B)
- THD+N ratio at 2 Vrms output signal: -119 dB (v2.0B)
- Two versions can be populated:
- v2.0A – traditional balanced output with inverted signal on cold lead
- v2.0B – simplified output with ground on cold lead
Original Addon BalOut was designed for H-DAC but as there has been interest in those boards, this new version is easier to use in other applications:
- No filter components
- Normal opamps instead of fully differential opamp
- Separete input signal pinheaders
- Mounting holes
- Reference designators on silk screen and cheaper 2-layer board
HP Buf headphone amplifier’s already excellent THD+N figures can be pushed extremely low by replacing OPA2134s with LM4562s. This gives huge performance boost:
- 5-8 dB lower noise floor, depending on gain setting
- Up to 12 dB better THD+N
- For example, THD+N at 100 mW into 32 Ω went down from 0.00065 % (-104 dB) to 0.00017 % (-115 dB)
- Very high performance preamplifier; measurement results with H-DAC and 2 Vrms output:
- Dynamic range / SNR: 116 dB (A-weighted)
- THD+N ratio: -102 dB (2.0 Vrms / 1 kHz, 48 kHz sample rate)
- Crosstalk at 10 kHz: -113 dB
- Very high performance headphone amplifier
- Dynamic range / SNR: 115 dB (A-weighted)
- Maximum output power / THD+N ratio:
- 22 mW / -98 dB into 560 ohms
- 230 mW / -85 dB into 33 ohms
- More gain can be added for higher output power
- Software controlled (Arduino compatible)
- Balanced outputs (XLR) on-board and unbalanced connectors (RCA) on H-DAC board
- Takes supplies and audio signals directly from H-DAC via pinheaders
- 10×10 cm 4-layer PCB shaped to fit tall components on H-DAC board; PGA4311 volume control, LM49724 and LM4562 opamps (or any with the same pinouts), TPA6120A2 headphone amplifier, optional THAT1606 balanced drivers
H-PreAmp is an addon board for H-DAC, transforming the fixed-output DAC into a very high quality preamplifier with integrated headphone amplifier. H-DAC and H-PreAmp together provide single-ended (RCA) and balanced (XLR) outputs as well as headphone amplifier.
- Very high performance; measurement results with coaxial S/PDIF input:
- Output level: 2.0 Vrms
- Dynamic range / SNR: 122 dB (A-weighted)
- THD+N ratio: -103 dB (0 dBFS/1 kHz signal, 48 kHz sample rate)
- Crosstalk: -128 dB at 1 kHz, -112 dB at 10 kHz
- Supports S/PDIF, Toslink, USB, and external I2S inputs
- Unbalanced outputs (RCA) on board, balanced (XLR) addon available
- Hardware-controlled – no need for microcontroller (but one can be added with addon)
- Can be powered by AC or DC supply
- Addon available to transform H-DAC into preamplifier/headphone amp
- New output stage addons can be easily designed to experiment with components and circuits
- CS8416 S/PDIF-receiver, PCM1794A DAC, LM4562 opamps (or any SO-8 dual opamp), PCM2707C USB-audio, LM2940/LM2990, TPS73633, TPS79133, and REG103 regulators
H-DAC is a high-performance 192 kHz / 24-bit capable DAC board with TI PCM1794A DAC. The board has two coaxial S/PDIF, two Toslink, and one I2S input that can be either on-board 48 kHz / 16-bit USB receiver or an external I2S-device. Input selection and settings are controlled with jumper links that can be replaced by mechanical switches or microcontroller addon board.
- LM4562 and NE5532 show almost identical performance in I/V stage, while OPA2134 is 2 dB weaker.
- LM4562 is the best performer in differential amplifier.
- The best solution is to use NE5532 in I/V-stage and LM4562 in differential amplifier as it gives almost identical performance to all-LM4562 implementation
- Differences in distortion are mostly due to odd left/right channel differences of PCM1794A.