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# nihtila.com

DIY electronics

## Sitemaps

- [XML Sitemap](https://nihtila.com/sitemap.xml): Contains all public & indexable URLs for this website.

## Posts

- [Updates and new Kaamos Tech store](https://nihtila.com/2023/09/30/updates-and-new-kaamos-tech-store/) - I am glad to announce the next step in nihtila.com and break the long silence. I have re-designed some of the boards that have been out of stock for long time and there are completely new designs in the pipeline as well. I have opened a new website and online store kaamostech.com for selling them
- [W-Input S - I2C controlled version of W-Input](https://nihtila.com/2020/12/28/w-input-s/) - This is a software-controlled version of W-Input compact S/PDIF receiver board. It offers basically the same features but requires control and setup via I2C bus. Note that control software is not provided but is required to get any audio out. Flexible digital input board combines I2S input and S/PDIF inputs One I2S input / passthrough
- [W-DAC S 4493 - I2C controlled version of W-DAC 4493](https://nihtila.com/2020/12/28/w-dac-s-4493/) - This board is a software-controlled version of W-DAC 4493, plus a few tricks added to improve it's practical performance and usability especially in preamplifier applications. Another new feature not possible in HW-controlled version is DSD support. Here are the new features summarised: I2C-controlled - requires a microcontroller (e.g. Arduino) or any I2C host for control
- [ADC AK5572 v1.2 available](https://nihtila.com/2020/07/05/adc-ak5572-v1-2/) - 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. Note that there is also v1.3 now. It is the same as v1.2 except the PCB is green. Changes are: XLR-connectors now fit completely on
- [Wee DAC addons - XLR output and extra S/PDIF inputs](https://nihtila.com/2019/11/05/wee-dac-addons/) - There are several addon boards for Wee DAC to expand feature set: W-Output XLR - Balanced XLR output for W-DAC W-Output XLR Mute - Balanced XLR output with Mute relay for W-DAC W-Input+ Combo - Extra Coaxial and Toslink S/PDIF inputs for W-Input W-Input+ Combo XLR - Extra AES/EBU XLR and Toslink S/PDIF inputs for
- [Elecrow PCB long term review](https://nihtila.com/2020/08/06/elecrow-pcb-long-term-review/) - I have been using Elecrow for years as my PCB supplier for DIY projects, consisting of over two dozen designs. I have tried assembled PCBs as well so I thought of writing about my experiences with Elecrow and overall ordering PCBs from China. Recently I have started using JLCPCB as well and I will come
- [JLSounds I2SoverUSB and miniDSP MCHStreamer USB-to-I2S boards with W-DAC](https://nihtila.com/2020/04/11/jlsounds-i2soverusb-and-minidsp-mchstreamer-usb-to-i2s-boards-with-w-dac/) - Two examples of USB to I2S boards have been tested with W-DAC. They both have very extensive but also different feature sets. Key takeaways from measurements are: Both can get the best performance out of W-DAC 4493: -115 dB THD+N and 121 dBA dynamic range Lack of galvanic isolation in MCHStreamer may become problematic though
- [ADC AK5572 - Very high performance audio AD-converter](https://nihtila.com/2020/02/02/adc-ak5572-very-high-performance-audio-ad-converter/) - Design See schematics PDF at bottom of the page or schematics walkthrough in the video above. Input circuit consists of simple high-pass and low-pass filtering and input protection, followed by buffers and finally differential amplifier for pre-ADC low-pass filtering and also biasing the input at half-rail. There is some level of input protection but it
- [Tip 4: Building a DIY reflow oven from two toaster ovens and Controleo3 kit](https://nihtila.com/2020/04/08/tip-4-building-a-diy-reflow-oven-from-two-toaster-ovens-and-controleo3-kit/) - When you mainly want to design new things, experiment, and measure, soldering hundreds of components is not the most interesting thing to do. Therefore, somewhere in last autumn I decided I will build a reflow oven. I ordered a Controleo3 kit but it took a couple of months to actually start it, and even building
- [W-DAC 4493 - Very high performance compact DAC](https://nihtila.com/2020/02/27/w-dac-4493-very-high-performance-compact-dac/) - Superb performance: THD+N ratio: -115 dB (1 kHz -1 dBFS) THD ratio: -121 dB (1 kHz, -2 dBFS) Dynamic range / SNR: 121 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 6
- [W-Input - Compact digital input board](https://nihtila.com/2019/11/05/w-input/) - 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
- [Final W-DAC 4493 development update](https://nihtila.com/2020/02/29/final-w-dac-4493-update/) - Finally it seems W-DAC shows superb and most of all consistent performance across boards. I needed to have a break for a few months from all of this as I got quite frustrated after manufacturing a batch of boards and then not meeting the performance I'd seen in tests before. Going after -115 dB THD+N
- [Bit-perfect ASIO drivers to solve issues with Windows audio quality](https://nihtila.com/2017/01/16/bit-perfect-asio-drivers-to-solve-issues-with-windows-audio-quality/) - By default, Windows audio quality can be technically inferior as has been shown in this measurement. ASIO drivers or similar can improve audio output significantly by bypassing Windows resampling and other not-so-well implemented audio processing stages. This post arose as a consequence of testing the USB-input of H-DAC. Its PCM2707C-circuit is capable of "only" 48 kHz
- [Hypex UcD180 Power Amplifier](https://nihtila.com/2014/11/19/hypex-ucd180-power-amplifier/) - This is not my own design but incorporates OEM/DIY modules from Hypex to make up a rather impressive stereo power amplifier: 2x Hypex UcD180HG HxR audio amplifier modules delivering 2x 180 W @ 4 Ω or 2x 120 W @ 8 Ω Hypex SMPS400A180 switched mode power supply designed for UcD180s with power rating of 400 W
- [SharcDSP - miniSHARC-based 8-Channel Digital Signal Processor](https://nihtila.com/2014/11/24/sharcdsp-minisharc-based-8-channel-digital-signal-processor/) - Digital signal processor designed for my 4-channel DIY system. 6 digital stereo inputs: 2 toslinks, 2 coaxial RCAs, 1 coaxial BNC and AES/EBU (XLR) 4 coaxial BNC stereo outputs offering 8-channel output where channels are mixed/filtered from two input channels All electrical connectors are transformer-isolated Can be used for crossover filtering for multi-way active speakers,
- [Dual Trafo Board - Small dual transformer board](https://nihtila.com/2017/01/01/dual-trafo-board-small-dual-transformer-board/) - Placeholders for two small, approximately 10 VA, dual-secondary PCB transformers One transformer in series configuration for dual (analog) supply One transformer in parallel configuration for single (digital) supply Independent circuits, no common ground Supports the most common transformer pinouts Fuses, rectifier bridges, and filtering capacitors Dual Trafo provides three unregulated low power voltage rails for mixed
- [H-DAC - High performance 192 kHz / 24-bit DAC with addon options](https://nihtila.com/2017/01/15/h-dac-high-performance-192-khz-24-bit-dac-with-addon-options/) - 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 BalOut - Balanced output addon for H-DAC](https://nihtila.com/2017/01/16/addon-balout-balanced-output-addon-for-h-dac/) - Very high performance; does not become bottleneck of H-DAC system Noise level: -117 dBV (A-weighted) THD+N ratio at 2 Vrms output signal: better than 109 dB Crosstalk at 10 kHz: 113 dB Balanced output buffer with low-pass filter Optional high-CMRR balanced drivers Takes power and audio signals directly from H-DAC 5x4 cm 4-layer PCB, LM49724 opamps (or any
- [Addon H-PreAmp - Preamplifier/headphone amplifier addon for H-DAC](https://nihtila.com/2017/01/25/addon-h-preamp-preamplifier-headphone-amplifier-addon-for-h-dac/) - 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
- [Smart PSU 3 - 3-channel linear DC power supply with monitors](https://nihtila.com/2017/01/26/smart-psu-3-3-channel-linear-dc-power-supply-with-monitors/) - Three linearly regulated fixed outputs One dual supply intended as analog supply One single supply intended as digital supply Common ground Undervoltage, overcurrent, and overtemperature monitor and protection Maximum 1 A per channel, depending on the design and cooling Output relays Software-controlled monitors (Arduino compatible) Can also be used without microcontroller 2x LT3081, LT3091, ATmega328P
- [Simple PSU 3 - 3-channel linear DC power supply](https://nihtila.com/2017/02/01/simple-psu-3-3-channel-linear-dc-power-supply/) - Three linearly regulated voltage outputs One dual supply for analog voltage supply One single supply for digital voltage supply Separate grounds Fuses, rectifier bridges, filter capacitors, and regulator circuits 2x LM317, LM337 (or any pin-compatible) SimplePSU3 contains three simple 3-pin adjustable regulator circuits. Its one dual (analog) supply and one single (digital) supply suits especially
- [PSU Pre 2016 - External power supply for DAC-preamplifier](https://nihtila.com/2017/02/05/psu-pre-2016-external-power-supply-for-dac-preamplifier/) - Dual Trafo Board and SmartPSU3 modules Two 3-channel power outputs for DAC-preamplifiers, total current capability being approximately: +14 V, 250 mA -14 V, 250 mA +7 V, 500 mA Over-current, under-voltage, and over-temperature protection provided by SmartPSU3 Error codes blinked by the front LED This is the device where Dual Trafo Board and SmartPSU3 were originally designed
- [Addon H-Filter - Simple through-hole balanced preamplifier addon for H-DAC](https://nihtila.com/2017/02/06/addon-h-filter-simple-through-hole-balanced-preamplifier-addon-for-h-dac/) - High performance; H-DAC + H-Filter system performance measured with fixed resistors: SNR: 119 dB (A-weighted) THD+N ratio (1 kHz / 2 Vrms): -100 dB Crosstalk: -112 dB at 1 kHz, -100 dB at 10 kHz I/V-stage, filters, output stage, and opamps implemented with through-hole components for easy experimentations Balanced outputs (XLR) on-board, uses unbalanced connectors (RCA)
- [HP Pre 2016 - DAC-preamplifier with headphone amplifier](https://nihtila.com/2017/02/12/hp-pre-2016-dac-preamplifier-with-headphone-amplifier/) - H-DAC and Addon H-PreAmp encased and used along with PSU Pre 2016 external power supply Very high performance DAC-preamplifier with headphone amplifier Compact and simplified design yet extensive list of features Coaxial, optical, and USB inputs DAC filter response switch Balanced (XLR) and unbalanced (RCA) outputs, approximately 2 Vrms output level HP Pre 2016 and PSU
- [Addon H-MCU - Microcontroller addon for H-DAC](https://nihtila.com/2017/02/18/addon-h-mcu-microcontroller-addon-for-h-dac/) - Provides microcontroller interface to H-DAC jumper-link pinheader Can be made Arduino-compatible with external USB-serial interface board Addon H-MCU is designed to help use H-DAC in projects where I use microcontroller for selecting input and filter settings. It makes it possible to switch input and DAC filter with external remote signals. Design and schematics This is
- [miniD Preamp - Tiny miniDSP-based 4-Channel Preamplifier](https://nihtila.com/2018/01/08/minid-preamp-oled-tiny-minidsp-based-4-channel-preamplifier/) - This is an updated version of my old miniD preamp from 2014 combining miniDSP and 4-channel DAC-preamplifier Small 4-channel preamplifier with digital signal processor and digital-to-analog converter DSP can be used for crossover for 2-way speaker or between speaker and subwoofer, and/or digital room correction 4 digital SPDIF stereo inputs and one analog input 4-channel
- [HP MoBo - Modular headphone amplifier motherboard](https://nihtila.com/2018/02/04/hp-mobo-modular-headphone-amplifier-motherboard/) - Motherboard for modular headphone amplifier system Motherboard with inputs, outputs, power distribution, and signal routing for amplifier daughterboard Balanced input Balanced and unbalanced outputs Output mute circuit Requires separate amplifier board HP MoBo is the basis of a modular headphone amplifier design. It provides input and output connections and simple power supply components (external power
- [HP TPA - Simple IC amplifier board for HP MoBo](https://nihtila.com/2018/02/04/hp-tpa-simple-ic-amplifier-board-for-hp-mobo/) - Amplifier daughterboard for HP MoBo modular headphone amplifier TPA6120A2-based simple-IC headphone amplifier amplifier Balanced input, balanced output Jumper link for extra gain option; default 0/10 dB SNR: 116-122 dB A-w depending on the gain and load combination THD+N ratio at 100 mW 300 Ω: 0.0015 % / -96 dB 32 Ω: 0.006 % / -84
- [HP Buf - High-current buffered amplifier board for HP MoBo](https://nihtila.com/2018/02/04/hp-buf-high-current-buffered-amplifier-board-for-hp-mobo/) - Amplifier daughterboard for HP MoBo modular headphone amplifier High-power high-performance balanced headphone amplifier daughterboard for HP MoBo Balanced input, balanced output Jumper link for two gain options, default 0/10 dB Jumper link for two output impedance options OPA2134 opamps followed by BUF634 or LME49600 buffers SNR: 113-121 dB A-w depending on the buffer, load, and
- [Modular HP Amp 2017](https://nihtila.com/2018/02/04/modular-hp-amp-2017/) - Modular headphone amplifier based on HP MoBo motherboard and changeable amplifier daughterboards: HP TPA - simple TPA6120A2-based amplifier HP Buf - BUF634- or LME49600-buffered amplifier Balanced input Balanced and unbalanced headphone output Output mute circuit Part of multi-component system with external power supply Design Modular HP Amp 2017 is based on HP MoBo encased in
- [Analog MV8-OP1 clone for Roland MV-8000/8800](https://nihtila.com/2018/04/09/analog-mv8-op1-clone-for-roland-mv-8000-8800/) - 6-channel analog output module for Roland MV-8000/8800; mimics analog part of Roland MV8-OP1 module Digital signal and supply connector with identical pinout to the original Same output level as the original High performance SNR: 118 dB (A-weighted) THD+N ratio: -103 dB min, -93 dB max Crosstalk: -112 dB max First I must say I have never
- [Wee DAC update 1 - First measurements](https://nihtila.com/2019/01/13/wee-dac-update-first-measurements/) - 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 First round of measurements I have
- [DAC digital filters part 2 - deeper dive into AK4490 and AK4493 filters](https://nihtila.com/2019/10/18/dac-digital-filters-part-2-deeper-dive-into-ak4490-and-ak4493-filters/) - This post delves into digital filters in AK4490 and AK4493 DACs used in W-DAC boards and provides extensive measurement results of the filters in time and frequency domain. This is not only relevant to these specific DAC chips and filters but general information on DAC digital filters from audio perspective. This is a practical approach
- [Coming soon - Wee DAC sneak peek](https://nihtila.com/2019/01/02/coming-soon-wee-dac-sneak-peek/) - 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
- [Wee DAC update 2 - Improving AK4490 performance on test board](https://nihtila.com/2019/02/10/wee-dac-update-improving-ak4490-performance-on-test-board/) - 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
- [Wee DAC update 3 - New LDO and AK4493 tests, and new boards designed](https://nihtila.com/2019/04/13/wee-dac-update-new-ldo-and-ak4493-tests-and-new-boards-designed/) - 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 Unfortunately due
- [Wee DAC update 4 - v1.1 boards](https://nihtila.com/2019/05/11/wee-dac-update-4-v1-1-boards/) - 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 Wee DAC development and measurements started with v1.0 boards followed by test boards measurements and now we have improved v1.1 boards ready. Changes in v1.1
- [Wee DAC update 5 - almost there!](https://nihtila.com/2019/08/19/wee-dac-update-5-almost-there/) - 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. Current status The downside of doing these projects in free time is that
- [W-DAC 4490 - Very high performance compact DAC](https://nihtila.com/2019/11/05/w-dac-4490/) - 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
- [SPDIF TX - I2S to S/PDIF converter](https://nihtila.com/2020/02/03/spdif-tx-i2s-to-s-pdif-converter/) - Design See schematics below or schematics walkthrough in the video above. I2S input can be a single header for stereo use or dual header for mono use. In both cases all clocks are coming from the board and buffered. Only Data direction is from source to SPDIF TX. In stereo mode Data goes directly to
- [Wee DAC baseboards](https://nihtila.com/2019/11/05/wee-dac-baseboards/) - Wee DAC is a flexible modular system and there are several different baseboards for different configurations depending on the system requirements: DAC with S/PDIF inputs or only I2S-input Two channel DAC or four channel (2x stereo) I2S DAC Number of S/PDIF inputs Vertical or horizontal stack of boards Configuration options There are four different boards
- [USBHI - USB-interface for headset](https://nihtila.com/2018/03/26/usbhi-usb-interface-for-headset/) - Simple USB audio interface for headset Based on PCM2912A reference design; single IC providing: USB-interface 2-channel DAC and headphone amplifier 1-channel ADC and microphone bias TRRS jack for headset, or headphones and microphone can be wired out separately CTIA or OMTP type jack can be selected with jumper link Not for higher end audio but
- [Tip 3: Robust high-bandwidth passive DIY probes](https://nihtila.com/2019/03/16/tip-3-robust-high-bandwidth-passive-diy-probes/) - These DIY probes are great addition to oscilloscope or other measurement instrument due to: Easy to build Low cost High bandwidth Robust Can be equipped with suitable connector or soldered directly on circuit under test Introduction Before presenting this great tip I must admit I did not come up with this idea. This type of
- [Headphones showcase at the Bristol Show](https://nihtila.com/2019/02/24/headphones-showcase-at-the-bristol-show/) - I went to the Bristol Hifi Show on Friday, mostly focusing on headphones. This is not a collection of reviews but a few notes about the more interesting higher end headphones on the market. The Bristol Show (previously Sound & Vision - The Bristol Show) took place this weekend at the Marriott City Centre hotel
- [Audiolab M-DAC measurements part 2 - digital filters](https://nihtila.com/2019/01/28/audiolab-m-dac-measurements-part-2-digital-filters/) - I bought a second hand M-DAC a while ago to have a well-known commercial reference in terms of measurements and sound. After teardown it is time for measurements. The first part focused on the base performance and this second part dives into the digital filters and their impact on measurements. In the first part all
- [Tip 2: Beware of ground issues when using laptop on bench](https://nihtila.com/2019/01/05/tip-2-beware-ground-issues-when-using-laptop-on-bench/) - Care must be taken when using ungrounded devices, such as laptop, on measurement bench There may be tens of volts difference between mains earth and ground of the ungrounded device It is not dangerous to you but to sensitive electronics it can be Easy solutions exist but sometimes problems may be tricky to identify Background
- [Audiolab M-DAC measurements part 1 - base performance](https://nihtila.com/2018/10/29/audiolab-m-dac-measurements-part-1-base-performance/) - I bought a second hand M-DAC a while ago to have a well-known commercial reference in terms of measurements and sound. After teardown it is time for measurements. This first part consists of basic performance measurements. I chose M-DAC as my reference for several reasons. First of all, it has been very popular and highly
- [Desktop Bass Stands with Tang Band W6-1139SIF and Linkwitz Transform](https://nihtila.com/2018/10/18/desktop-bass-stands-with-tang-band-w6-1139sif-and-linkwitz-transform/) - 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
- [Audiolab M-DAC teardown](https://nihtila.com/2018/09/06/audiolab-m-dac-teardown/) - I bought a second hand M-DAC to have a well-known commercial reference in terms of measurements and sound. Obviously I needed to open it and see what's inside. This is not a detailed reverse-engineering report but a glance inside with plenty of photos. Measurements are coming later. Introduction Audiolab M-DAC is one of those DACs
- [Few assembled Addon Balout v2 boards available](https://nihtila.com/2018/09/05/few-assembled-addon-balout-v2-boards-available/) - I have a few assembled and tested Addon BalOut boards available, with or without XLR connectors.
- [Addon BalOut v2 - Balanced output board](https://nihtila.com/2018/04/09/addon-balout-v2-balanced-output-board/) - 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
- [PCM1794A output stage opamp measurements: LM4562, NE5532, and OPA2134](https://nihtila.com/2017/01/08/pcm1794a-output-stage-opamp-measurements-lm4562-ne5532-and-opa2134/) - 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
- [New projects coming - hopefully with assembled boards](https://nihtila.com/2018/08/18/new-projects-coming-hopefully-with-assembled-boards/) - Last year and this spring I spent a lot of free-time on DIY electronics and as my full-time job is also electronics related, I needed to take a few-month break. I just didn't feel interested, inspired, or motivated anymore. During the time off I focused a bit more on my photography hobby. I hoped that
- [Benefits of balanced headphones interconnection](https://nihtila.com/2018/08/06/benefits-of-balanced-headphones-interconnection/) - In balanced connection both speakers are individually connected to amplifier using two wires for each channel Crosstalk can be improved by tens of dB by using balanced interconnection Common-impedance coupling seriously limits crosstalk in conventional unbalanced headphones Balanced output can be easily and cost-effectively added on designs; inverted signal is not required Here is a
- [Tip 1: Component check on printed paper before PCB order](https://nihtila.com/2018/05/03/tip-1-component-check-on-printed-paper-before-pcb-order/) - Easy and quick way to check new footprints, that you definitely read all datasheet measures correctly when drawing the footprint, is to print the layout on paper and fit components on it. It is highly recommended to check new footprints before sending PCB files for manufacturing. I check all new footprints, whether I have created
- [HP Buf improvements - 500 mW into 32 Ω headphones with 0.00015 % THD+N!](https://nihtila.com/2018/02/21/hp-buf-improvements-500-mw-into-32-ω-headphones-with-0-00015-thdn/) - 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
- [OnePlus 3 volume control step size and output level measurements](https://nihtila.com/2017/03/27/oneplus-3-volume-control-step-size-and-output-level-measurements/) - OnePlus 3's 16-step volume control has too coarse steps - 5 dB in the middle volume range. Maximum output level is -1.5 dBV (around 95 dB THD+N ratio), providing over 20 mW into a typical 32-ohm headphones - more than enough for any portable headphones. I've had my OnePlus 3 phone since last October. Generally
- [DAC digital filters and their impact in time and frequency domains](https://nihtila.com/2017/01/07/dac-digital-filters-and-their-impact-in-time-and-frequency-domains/) - Many DAC chips and devices using those chip have user selectable options for digital filter response to fine-tune tonal characteristics. I will take PCM1794A used on H-DAC as an example and see what effects these filter types have on impulse and frequency responses. This is just scratching the surface of the topic by briefly introducing some
- [Understanding audio measurements: noise, SNR, and dynamic range](https://nihtila.com/2017/01/08/understanding-audio-measurements-noise-snr-and-dynamic-range/) - SNR is a ratio of two measurements, level and noise measurements, expressed in dB. Signal level, measurement bandwidth, and weighting filter must be defined. Dynamic range is like SNR but noise is measured in the presence of small signal; results should be the same. Noise is one of the most important performance figures and typically
- [Understanding audio measurements: THD+N vs. amplitude and frequency](https://nihtila.com/2017/01/08/understanding-audio-measurements-thdn-vs-amplitude-and-frequency/) - Presents the unwanted part of signal - something that was not put there and should not be there. THD+N vs. amplitude graph is important as it reveals SNR, dynamic range, and THD+N ratio; all are expressed as ratio compared to a specified signal level. The difference between THD+N level and THD+N ratio must be understood. Signal level,
- [Understanding audio measurements: Crosstalk](https://nihtila.com/2017/01/08/understanding-audio-measurements-crosstalk/) - Expresses "leaking" between channels; it is measured by driving a stimulus signal in one channel while listening to the other. Crosstalk is expressed as a ratio between the quiet undriven channel and the stimulus in the driven channel, and given in decibels. In stereo system, crosstalk is measured by driving a stimulus signal in one
- [Designing Arduino-compatible board](https://nihtila.com/2017/01/25/designing-arduino-compatible-board/) - I have stated some of my boards as "Arduino-compatible" as many other DIY and commercial electronics you can find nowadays. Simply put it means that you can develop Arduino programs (sketches) for that board with the Arduino IDE. Here are some information and references how to make a board Arduino compatible and what it means.
- [PCM1794A left/right channel distortion difference](https://nihtila.com/2017/01/12/pcm1794a-leftright-channel-differences/) - Basically in all of my PCM1794A measurements I have seen something strange going on in the distortion figures between left and right channels. Right channel is constantly weaker but the results are very consistent between measurements, parts, and even different opamp models, while left channel shows better performance but the results are very inconsistent. I will
- [LME49724 vs. OPA1632 in Addon BalOut](https://nihtila.com/2017/01/16/lme49724-vs-opa1632-in-addon-balout/) - Following performance figures have been measured in Addon BalOut module: Both opamps are so good that it is difficult to measure differences directly. LME49724: Noise level: -117 dBV (A-weighted), THD+N ratio: at least -109 dB (1 kHz, 2 Vrms), around measurement instrument limits. OPA1632: Noise level: -118 dBV (A-weighted), THD+N level: at least -109 dB (1 kHz, 2 Vrms), around measurement
- [Site update and upcoming projects](https://nihtila.com/2018/01/01/site-update/) - Once again I will try to start updating the site a bit more often. To encourage myself to do so, I have updated the theme to something that is easier to manage and I am familiar with - the excellent Soledad I am also using in my Sunday Photographer photoblog. Although there hasn't been many
- [Win an oscilloscope in Keysight Scope Month - like I did last year!](https://nihtila.com/2017/03/10/win-an-oscilloscope-in-keysight-scope-month-like-i-did-last-year/) - It is March again, meaning Keysight are having their Scope Month where they give away impressive number of free oscilloscopes. You still have plenty of time to win as they draw names every day in March to give away their new 1000-series entry level scopes. While the scopes are significantly cheaper models than last year,

## Pages

- [Homepage](https://nihtila.com/) - Welcome This is a personal electronics website showcasing DIY projects, measurements, modifications, reviews and investigations, focus being mainly on audio. While this is all hobby-based, I have been selling very small quantities of boards to fund the hobby and future developments. In September 2023 I opened a new website kaamostech.com and will continue releasing new
- [Buy boards and PCBs](https://nihtila.com/shop/) - In September 2023 I have finally opened a new website and online store in kaamostech.com where you can find all the boards I currently sell with up-to-date stock. I have a small amount of older bare PCBs left and will try to write a list here later on. In the meantime, if you are after
- [My design philosophy](https://nihtila.com/general-info/design-philosophy/) - Audio electronics is one of the most controversial fields of electronics. High quality audio and hifi contain lots of strong beliefs and opinions and excess marketing jargon. Perception of sound and its quality is something we cannot express in numbers but is instead highly subjective matter, making it prone to strong arguments and debates. In
- [About](https://nihtila.com/about/) - I opened this website in 2013 to show my audio electronics projects and also to use it as a portfolio when looking for a job. After adding the initial content I did not really keep updating the site. After moving to a new country and somehow settling down, I got active in hobby electronics in
- [Wee DAC system](https://nihtila.com/wee-dac-system/) - Very high performance modular DAC system High system level flexibility Reusable boards Very high performance DACs, up to THD+N ratio: -115 dB THD ratio: -121 dB Dynamic range / SNR: 121 dBA Crosstalk: -125 dB, 10 kHz 32 bits / 768 kHz DAC (using direct I2S) Optional balanced output Range of inputs available Coaxial and
- [Store](https://nihtila.com/store/)
- [Cart](https://nihtila.com/cart/) - [woocommerce_cart]
- [Checkout](https://nihtila.com/checkout/) - [woocommerce_checkout]
- [My account](https://nihtila.com/my-account/) - [woocommerce_my_account]
- [Thank you](https://nihtila.com/thank-you/) - Thank you for your support! I am honestly grateful for that. It feels great someone appreciates the work you spend so much time on. It gives motivation to continue. Please feel free to provide feedback and suggestions in contact form. Thank you!-Tomi
- [Support](https://nihtila.com/support/) - DIY electronics is still a hobby for me, something I do beside my day job. Everything seen on this website has started from a personal interest or need. However, nowadays I also try to think of selling potential when designing a board. Even if I design it for myself, selling a couple of boards helps
- [Books, links, and articles](https://nihtila.com/general-info/bibliography/) - Besides direct links to product pages and datasheets in project pages, here is a list of literature I think is worth going through or know their existence. Besides my studies, at least some of these have been my source of information when designing all these projects. This is also my personal link list, occasionally I need
- [Assembly instructions](https://nihtila.com/general-info/assembly-instructions/) - Updated 18.2.2017 Unfortunately I do not have detailed instructions for each board and I expect potential builder to have relevant electronics skills. If there will be enough interest I may try to write better instructions for more complicated boards. General instructions Good basic electronics skills are expected: Good soldering skills Use decent soldering iron with small
- [General info](https://nihtila.com/general-info/)

## Categories

- [News](https://nihtila.com/category/news/)
- [Projects](https://nihtila.com/category/projects/)
- [Learning](https://nihtila.com/category/learning/)
- [Measurements](https://nihtila.com/category/measurements/)
- [Audio Theory](https://nihtila.com/category/learning/audio-theory/)
- [Reviews](https://nihtila.com/category/reviews/)
- [Kit](https://nihtila.com/category/kit/)
- [H-DAC](https://nihtila.com/category/projects/hdac/)
- [Audio Measurements](https://nihtila.com/category/measurements/audio-measurements/)
- [PSU](https://nihtila.com/category/projects/psu/)
- [Devices](https://nihtila.com/category/projects/devices/)
- [Microcontrollers](https://nihtila.com/category/learning/microcontrollers/)
- [Modular HP Amp](https://nihtila.com/category/projects/modular-hp-amp/)
- [Tips](https://nihtila.com/category/tips/)
- [Teardown](https://nihtila.com/category/learning/teardown/)
- [Speakers](https://nihtila.com/category/projects/speakers/)
- [Benchmark](https://nihtila.com/category/measurements/benchmark/)
- [Wee DAC](https://nihtila.com/category/projects/wee-dac/)
- [Development](https://nihtila.com/category/development/)
- [Obsolete](https://nihtila.com/category/obsolete/)

## Tags

- [genelec](https://nihtila.com/tag/genelec/)
- [DAC](https://nihtila.com/tag/dac/)
- [impulse response](https://nihtila.com/tag/impulse-response/)
- [measurement](https://nihtila.com/tag/measurement/)
- [noise](https://nihtila.com/tag/noise/)
- [SNR](https://nihtila.com/tag/snr/)
- [THD+N](https://nihtila.com/tag/thdn/)
- [dynamic range](https://nihtila.com/tag/dynamic-range/)
- [LM4562](https://nihtila.com/tag/lm4562/)
- [OPA2134](https://nihtila.com/tag/opa2134/)
- [NE5532](https://nihtila.com/tag/ne5532/)
- [crosstalk](https://nihtila.com/tag/crosstalk/)
- [fft](https://nihtila.com/tag/fft/)
- [weighting](https://nihtila.com/tag/weighting/)
- [measurement bandwidth](https://nihtila.com/tag/measurement-bandwidth/)
- [H-DAC](https://nihtila.com/tag/h-dac/)
- [signal processing](https://nihtila.com/tag/signal-processing/)
- [LME49724](https://nihtila.com/tag/lme49724/)
- [OPA1632](https://nihtila.com/tag/opa1632/)
- [PCM2707C](https://nihtila.com/tag/pcm2707c/)
- [Windows audio](https://nihtila.com/tag/windows-audio/)
- [oversampling](https://nihtila.com/tag/oversampling/)
- [USB-audio](https://nihtila.com/tag/usb-audio/)
- [asio](https://nihtila.com/tag/asio/)
- [foobar](https://nihtila.com/tag/foobar/)
- [ministreamer](https://nihtila.com/tag/ministreamer/)
- [asio4all](https://nihtila.com/tag/asio4all/)
- [resampling](https://nihtila.com/tag/resampling/)
- [distortion](https://nihtila.com/tag/distortion/)
- [Keysight](https://nihtila.com/tag/keysight/)
- [scope month](https://nihtila.com/tag/scope-month/)
- [oscilloscope](https://nihtila.com/tag/oscilloscope/)
- [contest](https://nihtila.com/tag/contest/)
- [OnePlus3](https://nihtila.com/tag/oneplus3/)
- [microcontroller](https://nihtila.com/tag/microcontroller/)
- [PGA4311](https://nihtila.com/tag/pga4311/)
- [TPA6120A2](https://nihtila.com/tag/tpa6120a2/)
- [THAT1606](https://nihtila.com/tag/that1606/)
- [PSU](https://nihtila.com/tag/psu/)
- [transformer](https://nihtila.com/tag/transformer/)
- [CS8416](https://nihtila.com/tag/cs8416/)
- [PCM1794A](https://nihtila.com/tag/pcm1794a/)
- [board](https://nihtila.com/tag/board/)
- [LT3081](https://nihtila.com/tag/lt3081/)
- [LT3091](https://nihtila.com/tag/lt3091/)
- [audio performance](https://nihtila.com/tag/audio-performance/)
- [audio measurement](https://nihtila.com/tag/audio-measurement/)
- [Addon H-PreAmp](https://nihtila.com/tag/addon-h-preamp/)
- [Schaeffer AG](https://nihtila.com/tag/schaeffer-ag/)
- [PSU Pre 2016](https://nihtila.com/tag/psu-pre-2016/)
- [HP Pre 2016](https://nihtila.com/tag/hp-pre-2016/)
- [Dual Trafo Board](https://nihtila.com/tag/dual-trafo-board/)
- [SmartPSU3](https://nihtila.com/tag/smartpsu3/)
- [Wordpress](https://nihtila.com/tag/wordpress/)
- [Soledad](https://nihtila.com/tag/soledad/)
- [volume control](https://nihtila.com/tag/volume-control/)
- [volume step](https://nihtila.com/tag/volume-step/)
- [output level](https://nihtila.com/tag/output-level/)
- [phone](https://nihtila.com/tag/phone/)
- [opamp comparison](https://nihtila.com/tag/opamp-comparison/)
- [I/V-stage](https://nihtila.com/tag/i-v-stage/)
- [differential amplifier](https://nihtila.com/tag/differential-amplifier/)
- [Addon BalOut](https://nihtila.com/tag/addon-balout/)
- [fully differential amplifier](https://nihtila.com/tag/fully-differential-amplifier/)
- [channel difference](https://nihtila.com/tag/channel-difference/)
- [decibels](https://nihtila.com/tag/decibels/)
- [white noise](https://nihtila.com/tag/white-noise/)
- [digital filter](https://nihtila.com/tag/digital-filter/)
- [image frequencies](https://nihtila.com/tag/image-frequencies/)
- [noise shaping](https://nihtila.com/tag/noise-shaping/)
- [filter delay](https://nihtila.com/tag/filter-delay/)
- [through-hole](https://nihtila.com/tag/through-hole/)
- [Bruno Putzeys](https://nihtila.com/tag/bruno-putzeys/)
- [Arduino-compatible](https://nihtila.com/tag/arduino-compatible/)
- [USB](https://nihtila.com/tag/usb/)
- [S/PDIF](https://nihtila.com/tag/s-pdif/)
- [192k/24b](https://nihtila.com/tag/192k-24b/)
- [balanced](https://nihtila.com/tag/balanced/)
- [bootloader](https://nihtila.com/tag/bootloader/)
- [programmer](https://nihtila.com/tag/programmer/)
- [AVR dragon](https://nihtila.com/tag/avr-dragon/)
- [FT232](https://nihtila.com/tag/ft232/)
- [preamplifier](https://nihtila.com/tag/preamplifier/)
- [headphone amplifier](https://nihtila.com/tag/headphone-amplifier/)
- [LM317](https://nihtila.com/tag/lm317/)
- [LM337](https://nihtila.com/tag/lm337/)
- [audio fundamentals](https://nihtila.com/tag/audio-fundamentals/)
- [switch noise](https://nihtila.com/tag/switch-noise/)
- [pops and clicks](https://nihtila.com/tag/pops-and-clicks/)
- [Hypex](https://nihtila.com/tag/hypex/)
- [Class D](https://nihtila.com/tag/class-d/)
- [power amplifier](https://nihtila.com/tag/power-amplifier/)
- [UcD180](https://nihtila.com/tag/ucd180/)
- [SMPS400A180](https://nihtila.com/tag/smps400a180/)
- [miniSHARC](https://nihtila.com/tag/minisharc/)
- [signal processor](https://nihtila.com/tag/signal-processor/)
- [miniDSP](https://nihtila.com/tag/minidsp/)
- [Room EQ Wizard](https://nihtila.com/tag/room-eq-wizard/)
- [UMIK-1](https://nihtila.com/tag/umik-1/)
- [miniD](https://nihtila.com/tag/minid/)
- [OLED](https://nihtila.com/tag/oled/)
- [SRC4392](https://nihtila.com/tag/src4392/)
- [PCM4104](https://nihtila.com/tag/pcm4104/)
- [OPA1662](https://nihtila.com/tag/opa1662/)
- [sample rate converter](https://nihtila.com/tag/sample-rate-converter/)
- [remote control](https://nihtila.com/tag/remote-control/)
- [modular](https://nihtila.com/tag/modular/)
- [BUF634](https://nihtila.com/tag/buf634/)
- [LME49600](https://nihtila.com/tag/lme49600/)
- [mute circuit](https://nihtila.com/tag/mute-circuit/)
- [balanced audio](https://nihtila.com/tag/balanced-audio/)
- [current limit](https://nihtila.com/tag/current-limit/)
- [HP Buf](https://nihtila.com/tag/hp-buf/)
- [HP TPA](https://nihtila.com/tag/hp-tpa/)
- [HP MoBo](https://nihtila.com/tag/hp-mobo/)
- [Hifiman HE-560](https://nihtila.com/tag/hifiman-he-560/)
- [balanced headphones](https://nihtila.com/tag/balanced-headphones/)
- [common-impedance coupling](https://nihtila.com/tag/common-impedance-coupling/)
- [USBHI](https://nihtila.com/tag/usbhi/)
- [ADC](https://nihtila.com/tag/adc/)
- [microphone](https://nihtila.com/tag/microphone/)
- [headset](https://nihtila.com/tag/headset/)
- [PCM2912A](https://nihtila.com/tag/pcm2912a/)
- [AK4396](https://nihtila.com/tag/ak4396/)
- [multi-channel](https://nihtila.com/tag/multi-channel/)
- [Roland](https://nihtila.com/tag/roland/)
- [MV8-OP1 Clone](https://nihtila.com/tag/mv8-op1-clone/)
- [PCB](https://nihtila.com/tag/pcb/)
- [manufacturing](https://nihtila.com/tag/manufacturing/)
- [design check](https://nihtila.com/tag/design-check/)
- [footprint](https://nihtila.com/tag/footprint/)
- [assembled board](https://nihtila.com/tag/assembled-board/)
- [Elecrow](https://nihtila.com/tag/elecrow/)
- [M-DAC](https://nihtila.com/tag/m-dac/)
- [NE5534](https://nihtila.com/tag/ne5534/)
- [ES9018](https://nihtila.com/tag/es9018/)
- [teardown](https://nihtila.com/tag/teardown/)
- [WM8805](https://nihtila.com/tag/wm8805/)
- [speaker](https://nihtila.com/tag/speaker/)
- [subwoofer](https://nihtila.com/tag/subwoofer/)
- [Linkwitz Transform](https://nihtila.com/tag/linkwitz-transform/)
- [room correction](https://nihtila.com/tag/room-correction/)
- [acoustics](https://nihtila.com/tag/acoustics/)
- [acoustic measurements](https://nihtila.com/tag/acoustic-measurements/)
- [Tang Band](https://nihtila.com/tag/tang-band/)
- [WinISD](https://nihtila.com/tag/winisd/)
- [Wee DAC](https://nihtila.com/tag/wee-dac/)
- [mains](https://nihtila.com/tag/mains/)
- [grounding](https://nihtila.com/tag/grounding/)
- [earth](https://nihtila.com/tag/earth/)
- [lab](https://nihtila.com/tag/lab/)
- [probe](https://nihtila.com/tag/probe/)
- [high bandwidth](https://nihtila.com/tag/high-bandwidth/)
- [AK4490](https://nihtila.com/tag/ak4490/)
- [headphones](https://nihtila.com/tag/headphones/)
- [event](https://nihtila.com/tag/event/)
- [review](https://nihtila.com/tag/review/)
- [AK4493](https://nihtila.com/tag/ak4493/)
- [LDO](https://nihtila.com/tag/ldo/)
- [W-DAC](https://nihtila.com/tag/w-dac/)
- [AK4115](https://nihtila.com/tag/ak4115/)
- [AES/EBU](https://nihtila.com/tag/aes-ebu/)
- [Toslink](https://nihtila.com/tag/toslink/)
- [baseboard](https://nihtila.com/tag/baseboard/)
- [breakout board](https://nihtila.com/tag/breakout-board/)
- [PSU board](https://nihtila.com/tag/psu-board/)
- [AK5572](https://nihtila.com/tag/ak5572/)
- [audio analyser](https://nihtila.com/tag/audio-analyser/)
- [I2S](https://nihtila.com/tag/i2s/)
- [reflow oven](https://nihtila.com/tag/reflow-oven/)
- [prototyping](https://nihtila.com/tag/prototyping/)
- [JLSounds I2SoverUSB](https://nihtila.com/tag/jlsounds-i2soverusb/)
- [miniDSP MCHStreamer](https://nihtila.com/tag/minidsp-mchstreamer/)
- [I2C](https://nihtila.com/tag/i2c/)
- [hybrid volume control](https://nihtila.com/tag/hybrid-volume-control/)
- [PCB design](https://nihtila.com/tag/pcb-design/)
- [PCB assembly](https://nihtila.com/tag/pcb-assembly/)
- [Digital Audio Receiver](https://nihtila.com/tag/digital-audio-receiver/)
- [digital volume control](https://nihtila.com/tag/digital-volume-control/)