GEEDIY 32Bit 1536KHZ DSD1024 I2S/DSD DAC Board Decoder Board Finished with AK4499EXEQ + AK4191EQ

GEEDIY 32Bit 1536KHZ DSD1024 I2S/DSD DAC Board Decoder Board Finished with AK4499EXEQ + AK4191EQ

Optional Versions:
* Finished Version: The finished board will only be shipped after testing! The board includes AK4499EXEQ and AK4191EQ chips. Finished boards are covered by a 30-day warranty from the date of purchase (any damage caused by the buyer is not covered). For users outside mainland China, the buyer is responsible for all shipping costs for warranty repairs.
* Semi-finished Kit: This version does not include the AK4499EXEQ and AK4191EQ chips. These two chips must be purchased separately by the user and soldered in. All other components are included! By default, only the SMD parts and a small number of through-hole components are pre-soldered. The remaining majority of through-hole components need to be soldered by the buyer. No warranty service.

Features:
* Optional main chips: AK4499EXEQ + AK4191EQ
* Independent power supply for each DAC chip
* Overall layout is based on the official Evaluation Board: Designed with reference to the official evaluation board layout (note: this is not a direct copy or clone — the overall structure follows the official design, but many modifications were made, it is not simply the official PCB reused). VREF uses two independent LT3042 regulators, and all other DAC chip sections are independently powered! The board supports switchable single-ended or differential outputs — you can switch between single-ended and differential with one action!
* The analog section of the DAC board is based on the official EVM design, ensuring more reliable performance.
* Op-amp configuration: IV conversion with OPA1612 ×2; single-ended output with OPA1611 ×2
* This version supports I2S/DSD decoding!
* Pure software control (onboard MCU)! Independent design for I2S/DSD signal input!
* I2S supports up to 32-bit data and 1536kHz sampling rate. DSD decoding supported: 2.8MHz, 5.6MHz, 11.2MHz, 22.5MHz, 45.15MHz (corresponding to DSD64, DSD128, DSD256, DSD512, DSD1024).
* Since the AK4499EXEQ + AK4191EQ adopt an entirely new design, all audio signals, whether I2S or DSD, can be automatically recognized losslessly (without affecting performance), so manual sampling rate control is no longer required!
* The board includes a mute function. And when used with the interface for Amanero, it can achieve noise-free track switching in DSD mode!
* It supports software-controlled volume (connect a 10K single-gang potentiometer to the VOL port; by default, if no potentiometer is connected, a jumper cap sets it to maximum volume).
* The differential (balanced) output or single-ended RCA output is switchable (via onboard relay). Since simultaneous output would affect performance, a switchable output design is used. Controlled via the XRSW port: default open = single-ended RCA output; shorting the XRSW port = XLR differential (balanced) output. The XRSW port can be connected to a latching or toggle switch for one-touch switching of output modes!
* PCB mainboard size: 16.6cm × 12.9cm

Test Parameters (tolerance ±1dB): 
* SNR: 126dB (balanced output), 125dB (RCA output)
* THD: –120dB, –123dB at Mode 2

Packing List:
* 1 × Finished DAC Board

Packaging Details:
* Weight: 0.52kg



Detailed Function Introduction & K-Port Function Overview (The K-Port works by controlling the onboard MCU, which in turn software-controls the DAC chips):
1. I2S Data Alignment Format Setting
Set via K-Port pins K1, K2, K3. See the diagram for details.


2. Digital Filter Setting
Set via K-Port pins K5, K6, K7. See the diagram for details.

Use only the first six digital filter settings. The last one, the Programmable Filter, requires special hardware and software and is generally not needed.

3. MCLK Signal Operating Frequency Setting
Set via K-Port pins K8, K9, KA. See the diagram for details.

Some MCLK frequencies outside the table can also work, but to ensure stability and compatibility, strictly follow the table's frequency range.

4. DSD Volumio Bypass Mode (Direct DSD Decoding)
Set via K-Port pin KB. When KB is open, normal mode is active; when KB is shorted, Volumio Bypass mode is enabled. In Volumio Bypass mode, the DSD filter can be used, but the DSD sampling rate is limited to a maximum of DSD512; DSD1024 cannot be used.

5. Synchronous/Asynchronous Mode Setting
Set via KC. When KC is open, synchronous mode is active (MCLK must be synchronized with BCK/LRCL/DCLK). When KC is shorted, asynchronous mode is active (MCLK does not need to synchronize with BCK/LRCL/DCLK).

6. DSD Filter Setting
Set via KD. When KD is open, the cutoff frequency is lower; when KD is shorted, the cutoff frequency is higher. The DSD filter only works in Volumio Bypass mode.

7. Enable or Disable Automatic DSD/PCM Recognition
Set via KF. When KF is open, automatic recognition is disabled; the DSD/PCM mode must be set via the DSDON signal or KG. When KF is shorted, automatic recognition mode is active. Since the chip's built-in automatic recognition is not 100% reliable, it is not recommended in scenarios where the signal changes frequently.

8. DSD/PCM Mode Setting
Set via KG. This function only works when automatic recognition is disabled. The DSD/PCM mode can be set using either the DSDON signal or KG:
* DSDON high (3.3V) = DSD mode
* DSDON low (0V) = PCM mode
* KG open = DSD mode
* KG shorted = PCM mode

Important: KG and DSDON signals cannot be used simultaneously. When using KG, disconnect DSDON; when using DSDON, disconnect KG. Failure to do so may damage the circuit.

9. Gain Setting
Set via K4:
* K4 open = high gain (3.75Vpp)
* K4 shorted = low gain (2.8Vpp)

High gain mode provides a higher SNR.

Note: Pin 7 (DATA2/NC/D2) of the I2S/DSD input port is unused; keep it open.

10. Mute Setting
Controlled via pin 8 of the I2S/DSD input port:
* High level input (3.3V) = mute
* Default open or low level input (0V) = normal playback

11. OSR Setting
Set via KE:
* KE shorted = OSR256 mode
* KE open = OSR128 mode. OSR128 mode has lower harmonic distortion.
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I2S Interface Definition:
* 1 DSDON/NC
* 2 GND
* 3 DATA/DSDL
* 4 BCK/DCLK
* 5 MCLK
* 6 LRCK/DSDR
* 7 NC
* 8 MUTE

DAC Board Power Supply Instructions:
* The analog op-amp section requires ±15V DC (DC ±15V MAX). Note: This is a dual ±15V DC input. Connecting AC or reversing the polarity may cause permanent circuit damage! For finished boards, doing so will also void the warranty. The maximum voltage range for the analog op-amp section is ±15V DC. Do not exceed this range, or the board may be damaged.
* Other power supplies: three sets of AC 9V (can also use DC 12V; polarity does not matter).
* Important: If the protection diode P6KE18A on the board is damaged (breakdown or burn-out), it is considered user-caused damage, and the warranty will be voided.

Note:
* Since the analog section of this board requires dual DC inputs, a rectified, filtered, and regulated power supply is needed. Users who require one may purchase it separately.
* As this board directly accepts I2S/DSD signals (without a digital receiver function), users who need coaxial or optical digital reception should purchase an additional module.
* Due to instability in the electronic components market, some components may be out of stock and substituted with other brands, but this will not affect actual performance. Please make sure that you don't mind before purchasing.
* This product does not provide schematics or other design documents! Only interface definitions are provided (described in the introduction or labeled on the board).