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CHEAP DAC KIT MINI2496 AK4396

DAC AKM AK4396

Introduction
       Stems from the desire to make DIY dac, with the first project-based DAC chip TDA1541 philips version of NOS (non over-sampling). My first project delayed first because of time, distance, and components. A strong desire to make the dac does not stop at all, so I decided to create an alternative DAC from AKM AK4396 chip based (Asahi Kasei Microdevices). I think this chip is "worth" from economic side,the price of this dac  will not hurt your wallet.

     If you follow the supplied kit from ebay seller is not totally wrong, don't forget to choose presoldered kit smd ic component (cirrus logic 8416, AK4396, hex inverter HC04) because this is the most difficult part soldered. Also don't forget to buy R-Core transformer that sugested with dac kit, good transformer to pair with this dac (after report of impression in diyaudio.com forum).

Some dac data copied from seller : 

• 128x Oversampling
• Sampling Rate: 30kHz ~ 216kHz
• 24Bit 8x Digital Filter (Slow-roll-off option)• Ripple: ± 0.005dB, Attenuation: 75dB
• High Tolerance to Clock Jitter
• Low Distortion Differential Output
• DSD data input available
• Digital de-emphasis for 32, 44.1, 48kHz sampling
• Soft Mute
• Digital Attenuator (Linear 256 steps)
• THD + N:-100dB
• DR, S / N: 120dB
• I / F format: MSB justified, 16/20/24bit LSB justified, I2S
• Master Clock: Normal Speed: 256fs, 384fs, 512fs, 768fs or 1152fs
Power: Dual 13-15V + Single 9-15V or dual 13-15V only

This is bareboard dac AK4396 unpopulated with simple signal/power trace route and Bill Of Material (BOM)  (credit to dario aka. cleve fremen of diyaudio.com) :

PCB with traces signal and power section

Link of Bill Of Material : 
on Scribd:  BOM AK4396 and AK4393/4395
on Mediafire : BOM

Please  notice to follow on BOM , that different value of resistor and capacitor LPF's section, in AK4396 use  : 2,4K ,150R  resistors and 680 pF capacitors.

LPF Section AK4393/4395 and AK4396 Comparison

On the output stage we have some option to applied :
- Opamp output
- LOT's (Line Out Transformer)
- Tubes output
- Capacitors output

I decide to choose first option opamp output stage because easy to implementation, simple, minimum workspace, also cheap. If don't like the signature of sound easily can swap out for change (use dip socket). This time i give a try opamp from Linear Technology LT 1361 (dual).

Tweaking

According to the BOM above, we can make some tweaking on parts : resistor, electrolytic and film capacitor, diode and regulator then applied to the specific section, especially LPF and Regulator.

My DAC AK4396 on the way of tweaking.

Update 02 October 2012

DAC AK4396 near final tweaking

1. Change Regulator 7809,7812 and 7912 to LM317 and LM337 (lower noise)

2. Change Standard Diode Bridges to sinterglass diode Telefunken (tfk) BYW54 (2A)

3. Change film caps on LPF section to sprague orange drop 330nf

4. Change PSU capacitor to Nichicon FW 4700 35v

Here the easy way to change regulators 7809/7812 and 7912 :

Change regulator 7912  to LM337

 Note  : To reach 12v on 7812 change R2 to 36k. or use LM 317/337 calculator. to find right combination between R1 and R2. 

Change regulator 7809  to LM317