夏季 DAC 原理和製作班 (AD1955) 5-SEP

Dear all,

The SMD close up will be post tonight.

You may no need to soldering all SMD first. It will hard to test at finish.
Please wait me 1 day.

The soldering guide will be update and send to you at 7-SEP.

Some error found and update the excel file now.

KK.

For all.

1. No need to soldering FB101-104, 201-202. We need to test the power supply first, if OK, then soldering it.

2. No need to soldering U302, U322, U303, U323 (5V LDO) in DAC section first.
We need to make sure the main power supply voltage is OK then solder it back.

3. No need to soldering U206, 207 (3.3V LDO) in Digital receiver section first.
We need to make sure the main power supply voltage is OK then solder it back.

4. No need to soldering U208-210 (5V LDO) in DIR section first.
We need to make sure the main power supply voltage is OK then solder it back.

KK

SMD soldering guide.

1N4148 SMD x 16 pcs.
1. Pre-soldering one side on PCB
2. Pick the diode and soldering it on PCB. (Pay attention on the direction)
3. X 16 process
4. Check it.
5. Soldering the another side.

SMD soldering guide II

SOIC
1. Pre-soldering one side, one point on PCB
2. Pick the device and soldering it on PCB. (Pay attention on the direction)
3. Soldering the another corner side.
4. Check it the direction again, try to position the IC as center as possible.
5. Soldering the solder mask to cover all pin.
6. Left hand to carry the PCB and have position approx of 45' degree, the right hand side to "tall" the solder mask, from top to down (Check with the movie)

Soldering Movie here

If not clear, I am seeking a place to let you download the original 15M

Sunday will post RESISTOR...........

Youtube movie link:

http://www.youtube.com/watch?v=Wa4kI62aZL4

http://tw.youtube.com/watch?v=wQXhny3R7lk

Resistor soldering:

1. Find the resistor according to the EXCEL worksheet, and match with PCB label.

2. Blend the leg at 90 degree.

3. Place on PCB (through hole) with same direction label. (see the photo for reference)

4. Soldering and cut the leg.

5. If you need to upgrade USB input module, no need to soldering the R211-R214

6. R551, 501, 401, 451 for IV conversion.

7. R422,R423, R522,R523 is for Un-balance out config, no need to soldering any resistor.

USB module for IIS.

1. You need USB module (TI PCM2706 / 2707)
2. Don't soldering R219-222.
3. Additional 10 wire need to soldering.
a) 4 wire is the input from IIS output (U204 26C32) to USB module in.
b) 4 wire is the output from USB module to PCB R219-222 terminal.
c) 8V power from Digital side.

When not connect USB wire from PC to DAC, the IIS data will be read from original IIS port.

When USB wire with PC is plug, the 5V will trigger the IIS data latch to USB stream.

The PCM2706/7 is USB1.1 device, 12Mbit throughput, (1200K / 8 = 150KB)if you output WAV file, it is not OK, may be not smooth.

And please set the USB device output at 44.1KHz at control panel.

It is a 256FS device, 44100 x 256 = 11.2896MHz.
AD1955 can support.

Monday schedule.

IC socket and resistor array.

1. Insert the IC socket follow the silk screen direction on PCB
2. Soldering one point first.
3. Make sure the socket as close as to PCB.
4. Soldering another one point, like SMD method.
5. Double check it is correct orientation, and close to PCB.
6. Soldering the remain pads.

For the resistor array, the Pin 1 is label by a white solid dot. Or you can refer to my diagram attached.

Please note:
1. Please let me know your progress by posting your photo, I can make a short comment to you.
2. I will take a rest at TUE night, so may be no any photo update at tomorrow night.
3. WED will be post :
Socket, Transistor soldering photo.

KK.

0.1uF and 0.01uF soldering
0.1uF label = 104 or = 100n or = 0.1 on the top of component, depends on the vendor

Simple placing the 0.1uF on the PCB (label by 0.1uF text), insert by same direction, easy to debug and professional looking.

0.01uF soldering
0.01uF label = 103 or = 10n or = 0.01 on the top of component, depends on the vendor

Simple placing the 0.1uF on the PCB (label by 0.01uF text), insert by same direction, easy to debug and professional looking.

Most of the 0.01uF are soldering at left hand side of the AC input (Parallel with Rectifier)

Soldering the TO-92 package transistor / mosfet

Mosfet 2SK246

TL431 Voltage reference

MJE253 PNP Power Transistor (need blend the leg with 90 degree)

2SC2240 NPN transistor

Pay attention :
1. Their model no. (Check in the photo attached)
2. The direction. Follow the shape in PCB is OK
3. They are not the same, cannot interchangable, don't solder at wrong location.
4. There are 5 MJE253 are need to mount on PCB. Pay attention on the mounting screw, please use M3 longer one (Come with 5 pcs), another side lock with the M3 NUT
The another 4 shorter M3 screw is for using mount on Heatsink (Another 2 pcs of MJE253 and 2 pcs of 780X series, will describe later)

There are another small signal transistor need to soldering.

Q201 : 9012 PNP transistor

Q202 : 9014 NPN transistor

Q601 : 2SB647 PNP transistor

Output stage transistors

1. There are 4 type transistor need to soldering
2SA970 x 8 pcs PNP transistor
2SC2240 x 8 pcs NPN transistor
2SD667 x 4 pcs NPN transistor
2SB647 x 4 pcs PNP transistor
Identify and classify it.

2. Soldering 2SA970 on PCB first.

3. Soldering 2SC2240.

4. Soldering 2SD667

5. Soldering 2SB647

Analog output terminal & Digital input terminal


Do you know why need to face opposite?



Power supply input terminal
It is placing at original direction.

When you wathing this photo, you will know why I need to face the Analog and Digital input terminal in reverse.

When you install the PCB to metal chassics, you need to consider the open a square hole to let this RJ45 out of the chassics.

If soldering the Analog and Digital terminal at original position, you are hard to install the wire to the terminal. Reverse the direction is easy to install any thick wire.

Header soldering.

1. Insert the header.
a) 3 pin for Optical input module.
b) 3 pin for XLR/OPT selection
c) 2 pin for Input selector (connect to alum front panel)
d) 5 pin and 8 pin for connect the LED / LCD display board.

For USB module user:

Need R211,212,213,214

Don't need R219,220,221,222


If you no need USB in, soldering all R219-222.

Relay is too easy, no need to teaching.

Multi-Turn resistor

100R (label as 101), Left channel 2, Right channel 2.


2K (label as 202), locate in analog power supply stage.

Final stage for default user :

1. 0.47uF (label as 470nF on top of components)

2. 2200pF (label as 2200 on top of component)

3. 680pF (label as 680, Orange-Brown colour)

Finally, install all your default E-cap, default diode.

The heatsink install is show in picture.


END OF DEFAULT SOLDERING GUIDE

kk sir .

可否介紹下怎樣裝BY229&MBR1060,(PLAN A)
最好同時有相片參考

THANKS
DYNA

Schottky will install at final stage.

Dyna, let you take the look first, I will re-order the sequence at tonight.

High grade audio E.Cap.

Sanyo OS-CON

MUSE KZ series (Top Performance)

11 pieces of OS-CON location,

Please pay attention.

I change two MUSE and two OS-CON to difference location.

For AD1955, it need Analog power supply VA, so I use MUSE instead of OS-CON.

Simply say: you solder the 11 OS-CON at correct location (same as my photo is OK)

KK sir .

Thanks for your photo .
我己咩零件都焊上版,其實有無問題?
定到測試時一定會PK呢?

THANKS
DYNA

No need to solder the LM1117 (total 9 pcs)

Otherwise, it cannot test.

If you can confirm :
1. The components soldering on PSU is correct.
2. Components function is OK.

Otherwise...

KK.

[quote:851ef79776="kk_ho"]No need to solder the LM1117 (total 9 pcs)

Otherwise, it cannot test.

If you can confirm :
1. The components soldering on PSU is correct.
2. Components function is OK.

Otherwise...

KK.[/quote]

KK sir

OK~己起返九副X上來,
別外如我加個USB codec是否R219至R222都要起返出來?

THanks!!!
DYNA

別外如我加個USB codec是否R219至R222都要起返出來?
// YES

Hi KK sir,

I am using default plan since I want to look for my dream component set myself. However it is really extremely hard to find all the components I desired in the market. Therefore I asked you and william for the upgrade plan late on yesterday. But William replied both upgrade plan A and B were not complete right now (some missing parts in both plans) because I was too late to request.

"Both heads cannot reach the shores", "兩頭唔到岸", 好慘! 頭髮白晒!

I think I cannot complete soldering my dac before Monday. 仲撲緊零件

BUT I would come on SEPT 15 to look at you testing for other c chings. I think I have no problem testing mine at home since in fact I have built several dac before: (3623, 8412, 8420, 5843, pcm63pk, 1704.......) If not many issues, I could handle the test at home.

話晒都係紅褲仔出身麻 !

If possible I would bring a small bottle to take some cleaning fluid home to wash the PCB myself. I know the washing procedure.

I also need to take LM1117 back and hope I can solder more b4 come to HK tomorrow.

autumnleafcat, we have complete plan A available, if you need, you can take it tomorrow.

KK also mentioned that he will have addl Plan A & Plan B available tomorrow, first come first serve....

All,

Yes, First come first serve for additional Plan A, B.

For the cleaning PCB liquid, not allow to take away. It is a controlled material.

KK Sir,

Big Problem!!, I have broken one leg of isolation plate  KA7809 in heatsink, do you have extra one? need urgent help......

Sugargar

Your broken Heatsink Leg ? or 7809 Leg ? or Isolated plate ?

There are no need isolated plate for 7809,5.

KK Sir,

Please see photo


Sugargar

KK Sir,

I've ordered LED Display for 1955 Pro but can I add $150 upgrade to LCD display? Last time watched the real case and LCD display seems very cool!!

As I am going to use 3 transformer in the DAC, want to ask if I use 18W, 12V(0.75A) x 2 transformer for digital parts in PCB, is the power sufficient to support the LCD display?  

Sugargar

Sugar and all,

I've ordered LED Display for 1955 Pro but can I add $150 upgrade to LCD display? Last time watched the real case and LCD display seems very cool!!

// OK. Can reserve.

As I am going to use 3 transformer in the DAC, want to ask if I use 18W, 12V(0.75A) x 2 transformer for digital parts in PCB, is the power sufficient to support the LCD display?  

// Enough. But our R-CORE is 28VA !!! Alot of margin.
Please check with attached photo, Sony CDP-X5000 consumption is 13W MAX, but it use R-50 (65VA MAX) for much much margin.

Also inlcude Schottky diode 10100 (10A @ 100V)

KK Sir,

Can I use 1A600V Schottky diode to replace MUR420?  Is it better?

Raphael

KK sir,

I've checked 1645 and 10100 spec and found that the reverse leakage current of schottky is surpprissingly high (4mA @ 20V reverse voltage), though it has favorable low (0.57V) forward voltage drop at large 16A foward current. That means even when the diode is switch-off, there is still 4mA current flowing from the 4700uF to the power transformer.

10100 is even worse

MUR420 seems normal on reverse current (in uA microamp range)

From the diagrams above, in order to use Schottky with least reverse current, the Schottky may use heatsink to keep it cool in operation.

Let me check and measure...

But the sound actual is good.

Maybe the forward characteristic of rectifying diode is more important than reverse characteristics. Letting more peak current to charge up the 4700uF capacitor compensates the minor 4mA loss in diode off.

Cat,

Please check one of the top SACD model in SONY.

They use 10200.

Don't ask me which SACD model la....

Down 1 grade....

What happen?

Give you SMD package of diode...

The diagram shows the current waveform of Schottky diode (grey color).

The diode is only conducting for a relatively small period in the cycle. But the forward current is huge in magnitude (10A peak can be expected).

Therefore the diode forward characteristics is critical. Lower voltage drop of Schottky not only means lower diode power loss but also ensures a practical low impedance path and fast switching response for the high current spike charging up the 4700uF capacitor (Close to idea diode).

When reverse bias, the 4mA leakage can be considered as a 5kohm load across the 4700uF capacitor (R=20V/4mA). Not a great issue in fact.

Having recongnized the result above, if we incorporating Schottky in our design, we should also employ higher current rating transformer so that to provide the high peak current in diode conduction. Otherwise, transformer becomes the limiting factor in the system.