Projects

Wee DAC

W-Input – Compact digital input board

by nihtila November 5, 2019

written by nihtila

Flexible digital input board combines I2S input and S/PDIF inputs
- One I2S input / passthrough
- One Toslink S/PDIF input
- One isolated coaxial S/PDIF input
- More inputs (Toslink / Coax / AES/EBU) can be added with addon board
I2S output (up to 192 kHz / 24-bit from S/PDIF)
High performance to match with high performance DACs
AK4115VQ S/PDIF receiver
Compact size at 70 mm x 50 mm
Can be used with W-DAC or any compatible I2S-input DAC
Wee DAC ecosystem offers numerous compatible boards
- S/PDIF input addon boards (Coax, Toslink, AES/EBU)
- DAC with balanced XLR addon
- Baseboards with or without power supply
Assembled boards available

November 5, 2019 4 comments

Wee DAC

W-DAC 4490 – Very high performance compact DAC

by nihtila November 5, 2019

written by nihtila

Very high performance
- THD+N ratio: -108 dB (1 kHz -5 dBFS)
- THD ratio: -115 dB (1 kHz, -10 dBFS)
- Dynamic range / SNR: 119 dBA
- Crosstalk: -125 dB, 10 kHz
- Comprehensive measurement data available
Unbalanced RCA, 2 V output level
- Balanced addon available
I2S input, supports up to 32 bits and 768 kHz sample rate
5 digital filters selectable with jumper links
AK4490EQ DAC, LM4562 opamps
Compact size at 70 mm x 50 mm
Can be used with any compatible I2S source or in Wee DAC system
Wee DAC ecosystem offers numerous compatible boards
- Balanced XLR addon
- S/PDIF input boards (Coax, Toslink, AES/EBU)
- Baseboards with or without power supply
Assembled boards available

November 5, 2019 0 comment

Wee DAC update 5 – almost there!

by nihtila August 19, 2019

written by nihtila

Progress has been slow due to other things in life but last few weeks have been busy on finalising everything. More measurements have been done and PCBs are finalised. First batch of boards is in production and should be available in September.

August 19, 2019 5 comments

Development Wee DAC

Wee DAC update 4 – v1.1 boards

by nihtila May 11, 2019

written by nihtila

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

May 11, 2019 7 comments

Development Wee DAC

Wee DAC update 3 – New LDO and AK4493 tests, and new boards designed

by nihtila April 13, 2019

written by nihtila

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

April 13, 2019 16 comments

Development Wee DAC

Wee DAC update 2 – Improving AK4490 performance on test board

by nihtila February 10, 2019

written by nihtila

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

February 10, 2019 7 comments

Development Wee DAC

Wee DAC update 1 – First measurements

by nihtila January 13, 2019

written by nihtila

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

January 13, 2019 3 comments

Development News Wee DAC

Coming soon – Wee DAC sneak peek

by nihtila January 2, 2019

written by nihtila

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

January 2, 2019 8 comments

Speakers

Desktop Bass Stands with Tang Band W6-1139SIF and Linkwitz Transform

by nihtila October 18, 2018

written by nihtila

Small sealed subwoofer stands for desktop monitor speakers

Tang Band W6-1139SIF 6.5″ woofer
Sealed cabinet with around 10 litre volume
Form factor to fit behind computer monitors; white paint and black fabric finish to fit desktop environment
Linkwitz Transform and digital room correction on miniDSP
Woofer size and cabinet size limit performance but gives solid boost for small speakers

October 18, 2018 4 comments

Projects

Addon BalOut v2 – Balanced output board

by nihtila April 9, 2018

written by nihtila

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

April 9, 2018 0 comment

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