AW-D1 Installation Guidelines

 by  Comzone

AW-D1 is an easy to build, first of all, Please go to the "Download Area" and download the Part List and Schematics. Then you must buy the necessary stuffs！Because of different peoples have different taste, Audio Workshop ONLY provides the basic stuffs such as PCB, ICs and Oscillators.

Power supply parts

AW-D1 is just a single DAC board. It needs an external DC power supply. D1's minimum requirements are 4 DC supplies. They are

1)Digital Part (VD)

2)Digital Receiver Analog part (VA1)

3)DAC Analog part (VA2)

4)Low Pass Filter Analog Part (VA3)

(Audio Workshop AW-R1 power supply is well suitable for AW-D1)

VA3 is designed for single channel, DIYer can use separated power supply into Left and Right channels. Voltage requirements are as follows:

VD: 5V

VA1: 5V

VA2: 5V (CS43122 use 5.5V)

VA3: ±12V to ±18V (Voltage is based on the max. voltage of each Op-amps used)

Because of the low power consumption, one can use easy made power supply. For me, that is LM317 and LM337. Also, you can try to use some high grade LT317 and LT337 as regulators.

D1 has 2 digital inputs, they are SPDIF Coaxial and Toslink Optical. Optical input will pass though C8 to CS8414's RXN, so the signal will be out of  phase. Coaxial signal will pass though C1 to 74HC04 NOT Gate for the signal rebuild ,so C1 and C8 should use some Low loss angle MKT / MKP Capacitors. Value should between 0.01uF to  0.047uF.

For Oscillator, Both Full Size and Half Size can be used. DIYer need only match the triangle mark which is printed on the PCB, of course, you can use much higher end TCXO! C5 is coupling capacitor, you can install the same type capacitor  as C1 and C8, or just short circuit (jumper it).

For input signal selection, I will not use single Jumper to do the selection. The method I used is "Low Loss Grounding Method". To choose optical input, please make  “short for optical” to short circuit and “short for coaxial” to open circuit. When use Coaxial, the method is just vice versa. The short coming is need to control 2 jumpers. The advantage is Lower Distortion because it minimize the loss for the jumper when the signal will not pass though the jumper. It also gives a convenient way for building the selecter when put the DAC into the case.

The PCB has two 1kohm resistors haven't R marks, please do not install it. R13, R15, R16 and R20 is just optional. R19 (10k) and C14 (47uF) is CS4396/CS43122's RC Auto Reset Circuit, but the setting marked on the PCB is so conservative. When CS8414 start to lock up the signal (i.e. LED start to ON = switch on the DAC / change disc), it may not be reset well and make the output volume extremely low (but it will be normal after 5 to 10 seconds). There are 2 methods to solve the problem. First, the easy way out Reset it manually. Second, change the values of R19 and C14. DIYer can try 5k and 10uF.

Because of the extremely high power sensitivity of CS4396/CS43122 chips. If the DC power haven't any Reverse Protection (i.e. a diode connected between input and output of the regulator), please connect R18 with a value not more than 10 ohm and cut the trace which at the bottom of the location of R18! It is because when I make the first Prototype, I use Switching Power Supply to test the board. Unfortunately, I make one CS4396 and one CS43122 burn !!!!! (This is the main reason why AW-D1 was delayed. And the second Prototype testing period is nearly 6 months!)

For Mode Setting part, there are 3 pins (M4, M3 and M2). You can refer to the Schematics. Normally, we just connect 3 1k ohm resister as the setting below (also shown on the figure above):

M4=Low; M3 = High; M2 = High

For the outputs of the DAC chip, there is a constant DC output. The voltage is about half of VA2 (for CS43122,that is 2.75V; for CS4396, that is 2.5V). So, coupling capacitor is necessary. C26 to C33 fill this function and they have great influence on the sound quality. You may use 2.2uF Electrolytic Capacitors parallel with 0.1uF Metallized Film Capacitors (MKT / MKP), OR use all MKT / MKP, OR use Oil Capacitors. It is the main advantage of DIY Audio. You can use different values and types of components with suits your individual taste! ……Build your own acoustic works！

You can see how I did on the figure above. I jump those capacitors (Short Circuit), because I want to listen the original sound of that DAC, and the coupling capacitor alter the sound. However, not all DAC can be short circuited. CS4396/CS43122 can handle it because of the true balanced output. The designed balanced Low Pass Filter can filter out the DC current.

For the components of Low Pass Filter, you can try to use better stuffs. Usually, expansive stuff used in the analog part is more difference/effective than in digital part. I usually use Holco resisters together with Silver Mica Capacitors.  In Op-amp, High price/preference ratio OPA134 is the best choice! Of course, OPA627 and AD797 can also be used.

The overall sound quality…… It must explored by yourself! Although this DAC at first seems more trouble than that of others, CS43122 only appears in the machine price above USD$2000.

Audio Workshop's goal is to share it to All DIYer worldwide at the lowest price possible!

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