Measurements on slightly larger v1.1 boards:
- Superb performance using the best configuration, peaking at -112 dB to -114 dB THD+N
- Excellent performance using cheaper components
- Lots of changes on PCBs
Follow-up on AK4490 test board measurements
- Comparing cheap LDOs to superb LT3042
- LP2992 shows excellent performance
- AK4493 vs. AK4490
- Even better performance
- Almost pin compatible
- New v1.1 boards in production
- Slightly larger but still ‘wee’
- Supports AK4490 and AK4493, and different LDOs
- Possibly two or three assembly versions with different price and performance
Measurements and experiments carried out on a more spacious AK4490 test board
- Better understanding on improving AK4490 performance
- Encouraging results regarding Wee DAC performance goals
- Massive boost of 10-15 dB in THD+N at low frequencies
- THD+N at 1 kHz measured beyond -110 dB on test board
- Does not mean Wee DAC will achieve these though
- Modifications will increase BOM cost so need to consider the benefits and find a good compromise
Summary of initial Wee DAC tests:
- Estimated performance:
- SNR and Dynamic Range: around 120 dBA
- THD+N: at least -105 dB @ 1 kHz, 0 dBFS
- This performance is not achievable on the first/current PCB revision; re-spin required
- More performance studies on AK4490 will be carried out before PCB re-spin
Currently on test bench is a new stackable modular DAC design, Wee DAC (maybe should have called it Tower DAC!), consisting of several modules:
- W-Input – S/PDIF input board with one coaxial and one Toslink input, and I2S output
- W-DAC – High performance 768 kHz 32-bit DAC with I2S input and single-ended analog output
- W-Output XLR – Balanced output module
- Several base board options, such as W-Breakout for signal breakout and W-PSU for individual power supplies
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