1diy group design & Learn Product Development - 100Wrms Power Amplifier

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Your comments are valuable to us.  Thanks.

Instead of customer,  why not a "co developer?"    This project is intended for a group design :  me, him, her, you, at sama-sama tayo na i-develope,   welcome and join to design a common platform of Learning HW, SW and systems integrations and systematical Product/Project Development,  so we can diy learn to implement it and handle future personal or customer project - - - - - -  empower our fellow hobbyist to become a real player.

Oh! I alloted 4 guys  and 1 girl for the component systems to help me developed this project, to make it sure that it is a "success project",  one handsome guy is in  Mindanao and the other in foreign countries,  kaya naman panay ang English.

I have one slot remaining,  and I am planning to send it to you, subject for approval by the team decision.  note,  I cannot send all materials,  systems,  etc.....  perhaps only some to get you going, see below,    

who's the girl?  

i think for now i can be part in the protection side of the audio system, psu protection from ovr voltage and over current, gfci, soft power on and power amps protections. all i need is to coordinate with the mcu guy to incorporate this protections.

[Dandy]

who's the girl?  

i think for now i can be part in the protection side of the audio system, psu protection from ovr voltage and over current, gfci, soft power on and power amps protections. all i need is to coordinate with the mcu guy to incorporate this protections.

Thanks sis Piona,  that is a big help....... great!  

hmmm, the girl?   her name is Anna and she's not here in Philippines, she is taking care of parts, making the BOM cost as low as practical.  

Here is an update for this project :
1.  I am waiting for the "bring up test"  items  for the EQUALIZER  (DR100W_EQ prototype)  from one of our friend.
2. Tonight or later this afternoon,  the test can be carried on
3.  The PT2389 protoype has been assembled on the Universal PCB

4.  Intial MMI on the  software  to control the DR100W_EQ is ready, waiting for the Integration of HW and SW.

[Dandy]

Test ITEMS for the Bring up Test:   
Here as follows  the test items intended for the DR100W_EQ  and its power supply (prototype on the Universal PCB).     Well,  the Digital Volume Control  is not included on this test,  it will come next after the test on  (a)  PT2389 preset Equalizer  and  (b) LM317 Power Supply.

EQ Bring Up Test items:

1. Standby mode,  IC  pin voltage
2. Input Power Supply Variation
a) +5Vdc

2) Input Sensitivity = __________mVrms
Vout max == __________Vrms 
Distortion at Voutmax =__________ %

b) +9Vdc
Input Sensitivity = __________mVrms
Vout max == __________Vrms 
Distortion at Voutmax = __________%


3. Power Consumption , +9Vdc
a) Standby, flat response at  input Sensitivity
b) Bass Boost
c) 3D

4. EQ Test   Gain versus Frequencies.
Flat, Rock, Classic, Pop, Jazz, Bass Boost -- > square wave signal at 100mVrms input

a)   80 Hz
b)   400 Hz
c)   1KHz
d)   10 KHz
e)   16 KHz

5. Signal distortion checking
a) Square Wave, ringing drop out, flatness  @ 100mVrms input


6. Functional test,  Audio signal with music +  just use Manual switch

7. Integration  :   Added the  MCU control to the PT2389 preset –Equalizer

8. Systems Test  :
DR100W_EQ + LM317 Power Supply  (prototype)   +  DR100W_CM (prototype using NE2ss board)   +   DR20W  Amplifier   :   music Test


Power Supply Bring Up Test Items :

1.  Voltage output
a)   Vout_normal  unloaded    =   _________Vdc
b)   Vout_normal  Loaded    =   _________Vdc
c)   Vout_shutdown =  ___________mVdc

3.   Nominal unreg Voltage input  to maintained  +9Vdc =    _________Vdc

4.   Current Consumption
a)   +9Vdc   = ____________ mA
b)   Shutdown  = ___________mA


Note:
LM317 shutdown, can be manually put the ADJ pin to GND,  no software provision control yet.

Alright!..!!!!   The HW team have an idea what to perform, - I hope those guys will not be too drunk or so busy to perform the “Bring Up Test” -  oh!!!!  Just today is ………………Friday, its party time.

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i think i will be scheduled for china this sept.

will u be there?

[Dandy]

i think i will be scheduled for china this sept.

will u be there?

no!!!!     my schedule to be in China will be on..... one of the biggest show on earth in HK, Guangzhuo, shenzhen, shang hai,  October 10, 2011 onward,  one month to save budget and plan for it.




Back to the topic...........   The HW team have partial result as of last night.   Here as follows :

DR100W_EQ  prototype,  only the PT2389  pre-set Equalizer is assembled


They used square wave input signal, 1 KHz  about 100mVrms


At flat response, the output is

It is not really “FLAT” ,  there is an introduction of frequency boost.  I supposed to believe,  “flat” means,  a replica of the input signal.   Well,  just keep it  that way, see some next test.

[Dandy]

EQ Bring Up Test Result    <edited to complete the Test item   >

1.   Standby mode,  IC  pin voltage   {TBA}
2.   Input Power Supply Variation
a)   +5Vdc
Input Sensitivity =   460 mVrms   sinewave 1 KHz
Vout max ==  1.1 Vrms  


b)   +9Vdc
Input Sensitivity =  1.78 Vrms  sinewave 1 KHz
Vout max ==   2.6 Vrms  
 


3.   Power Consumption , +9Vdc
a)   Standby, flat response at  input Sensitivity  :  31.1 mAmp
b)   Bass Boost    :    35 mAmp
c)   3D                 :   39 mAmp

{TBA}

4.   EQ Test   Gain versus Frequencies.
Flat, Rock, Classic, Pop, Jazz, Bass Boost -- > square wave signal at 200mVrms input ,  1KHz     <different waveform occur at different Frequencies,  for waveform reference, we refer it at 1 KHz>

a)   Flat  Response
      

The output (blue color) is compared with the input signal (yellow).  Originally, I though that output signal  comes with high Frequency component boost,  but not really.   Further test shows that, it is actually low frequency loss, which means at 1KHz, the Bass experienced loss  (cut).

      
b)   Rock


c)   Pops



d)   Classics


e)   Jazz



At Flat Response, this is how the Bass boost do :


From this waveform,  the Low Frequency (Bass)  is boosted (the right side of the square represent the low frequencies {Bass},  the lest side of the square wave represent the high frequency {Treble}),  in this waveform the turnover frequency is 1 KHz.


At Flat Response,  the 3D is activated    


It looks that it is “oscillating”,  ……….. but not really..!  Just,  this is how it appears.    With 3D sound,  in its general sense,  either  the L+R is added or subtracted,  then fed into phase reversal and other processing,  then fed-in back to the Left and Right Channels.   Combining a basic signal  and phase reversal signal will result into the waveform  shown above.


5.   Signal distortion checking
a)   Square Wave, ringing drop out, flatness  @ 200mVrms input


Exploded square wave output shows that there is a “ringing” on the rise edge of the signal.   With the condition on the Universal PCB, it would be difficult to locate the fault,  let me reserved to fix this on the actual PCB.


6.   Functional test,  Audio signal with music [DR100W_EQ prototype + DR100W_CM prototype with digital Class-T Power Amp ]
7.    Integration  :   Added the  MCU control to the PT2389 preset –Equalizer







Actual Listening test :
Music Source  :   MP4 Player
DR100W_EQ   :  set to  Flat, Rock, Pops, Classics, Jazz, blended with Bass Boost & 3D
DR100W_CM   :  Running Test Software to  control the  EQ
Power Amplifier  :    Digital Class-T Power Amplifier
Power Supply      :   Single +13.8V


 
Here is the MMI  <<just defined an interface how to access the tone, menu driven selection>>




 Note:
It used the NE2ss Trainer Board and convert it into a DR100W_CM prototype,  See the NE2ss specs and Trainer Board here,      http://www.1diycentre.com/DIYers_Space_files/Page850.htm      and   http://www.electronicslab.ph/forum/index.php?topic=21888.0



8.   Systems Test  :
DR100W_EQ + LM317 Power Supply  (prototype)   +  DR100W_CM (prototype using NE2ss board)   +   digital Class-T Power Amplifier   :   music Test / Noise Test
{TBA :  upcoming,  reserved for the test, including  the digital volume control }



Power Supply Bring Up Test Items :
Here is the LM317 assembled on the Universal PCB




  1.  Voltage output
d)   Vout_normal  unloaded    =   9.03 Vdc
e)   Vout_normal  Loaded    =    9.03Vdc
f)   Vout_shutdown =    1.25 Vdc

5.   Nominal unreg Voltage input  to maintained  +9Vdc =    11.8 Vdc

6.   Current Consumption
a)   +9Vdc   =   30 ~32  mA
Shutdown  =    0.6 mA

Well,  this is not good enough,  I expect  for a  standby current in the order of micro ampere,  0.6 mAmp high, let me consult the HW team if they can make a better solution   , any help is highly appreciated

[Dandy]

Good job  – the bring up test is a success.   There are 2 issues to look at :
1.   Output signal Ringing   <test on actual pcb>
2.   Shutdown Power Consumption   <check to improved it>

The live audio test shown above convinced the “test engineer” that  DR100W_EQ  is an add an value module  - - - -  a audio hobbyist should never missed to include into his Power Amplifier Systems.

I actually made the test last night along with other guys,  it is convincing of an acceptable perrmance with respect to no Equalization al all.   The most  noticeable big performance is the Bass Boost and 3D sound  (I think the 3D sound is as good as the surround sound of the DATC  with  TDA7442D  audio processor).

Observations :
1.   When changing the EQ,  On/off the Bass  ---à I can hear a bit click on the loud speaker  < could this be eliminated with the use of MUTE?>

[Dandy]

WHAT IS NEXT?
The next thing to do is to handle the  Digital Volume Control.

It was conceived to have only the digital  volume control controllable by I2C,  but further discussion with other guys  (our co-developers),  suggest to use the TDA7442D  which is the same digitally controlled surround processor used in the DATC Tone Control,  since  it was noted that we still have around 500 pcs on stock.   The idea is to consumed it,  and  used only the Volume Control function  or the Speaker Attenuation Control.  However,  it was noted that the part is SMT.

To shorten the decision,  from the PT2257  digital volume control - - -  original design,  it finally arrived to use the TDA7449  which is the same price.    

Why?
1.   The price is the same   <vendor reference>
2.   The TDA7449 comes with  Gain control, Volume, Bass and Treble control, Speaker Attenuation Control,    which has more option that the PT2257.  The idea is that,   with further  study or practice on the software programming (since, this is a part of diy Learning of Firmware programming),  there are more option to program
a)   Gain   0  to 30 dB
b)   Bass   :  +/- 14 dB
c)   Treble  :  +/- 14 dB
d)   Volume
e)   Speaker Attenuation

For the DR100W_EQ  shareware version, we will use only the function of  Volume Control,   thus, other options will be :
a)   Gain = 0 dB
b)   Bass = 0 dB
c)   Treble = 0 dB
d)   Speaker Attenuation = 0 dB
e)   Volume  =  0 dB  to  Mute     (indicated as Attenuation :  0 dB means  volume Max,   -80 db means  MUTE

For individual  like,  The Gain Control, Treble and Bass  can be included into the MENU of the MMI  in the DR100W_CM.   If a low  input signal can be boosted into several dB by adjusting the Gain.    If the EQ is not good enough,  you can still increase the Bass and Treble   (just don’t over drive the EQ).

Further Next?
It looks that,  To test it, we need to use  software control to go along with the digital volume control.   As I am looking at the  datasheet,  there is a default wake up setting on page 10,   like  :

 Input =  input 2
Gain   : 28 dB
Volume =  Mute

Nahhhh!   It is not possible,  since the Volume is already muted  upon power on.   I need a software control to UNMUTE it.

{{{This is reserved for the  TDA7449 Schematic}}}}

[Dandy]

There is no work in Philippine today  (August 29, 2011) ,  a leverage for our HW team.   Here,  is the TDA7449  Integrated into the existing PT2389 + LM317  PCB  (our DR100W_EQ  Prototype on the Universal PCB).


The wire with color red, black and yellow is for the I2C control.

The  Bass and Treble components were not installed,  it will just be controlled by software to set the parameter to  0 dB so there is no affect into the signal , no boost, no cut -- it is flat response.

Let see how it work,  a simple program to perform I2C protocol by the DR100W_CM  prototype, commanding the TDA7449 to:
1.   Select  Input 2
2.   Select Gain = 0 dB
3.   Volume  =  0 dB     (zero attenuation)
4.   Bass = 0 dB  :  Flat Response
5.   Treble = 0 dB   :  Flat Response
6.   Speaker attenuation =  0 dB

Using the NE2ss Trainer Board – converting it into a DR100W_CM prototype


The above picture is the integration of  TDA7449 hardware and its program.    

It is intended to test only the TDA7449 – a bring up test.    The PT2389 is not included in this test.

What is Next?
Let’s define the Bring-Up test items  for the TDA7449 - - - before we do electrical test.

[Dandy]

Test Item for the Bring-up Test for the TDA7442D :

1.   Sensitivity, sine wave, 1 KHz  =     __________ mVrms
2.   Max Output, sine wave, 1 KHz   =   __________Vrms
3.   Current Consumption @ rated supply (+9V)  =     ____________mAmp
4.   Current Consumption @ Shutdown supply (+9V)  =    _______mAmp (uAmp)
5.   Input / Output distortion , sine wave and square wave

Condition of TDA7449:
a)   Select  Input 2
b)   Select Gain = 0 dB
c)          Volume  =  0 dB
d)          Bass = 0 dB
e)   Treble = 0 dB
f)          Speaker attenuation =  0 dB


Note:
As I mentioned above,    we really need a program to make the TDA7449 to work.   So,  before we can test it,   let’s start  to know how we can set the Initial  data of TDA7449  after Power On.

[Dandy]

It’s  Software study time.      
 
To cut the discussion,  If you are a STARTER in Software for the Intel8051 core, I would like to refer you to  see this documents,  to get you going faster to know about
1.   Intel 8051 core MCU particularly the AT89S52
2.   BASCOM 8051 IDE  (Integrated Development Envirnonment)
3.   Programmer

Go to this link and download :   http://www.1diycentre.com/index_files/Page378.htm

a)   Simple MCU Programming Part –1
b)   Simple MCU Programming Part –3

Part 1 is the basics of the BASIC?
Part  3 is the implementation of those BASICs,  including the  EEPROM access,  see page 202.

Our main interest here is to make a program to control the TDA7449 – that means,  we need to know about I2C software control.  With BASCOM 8051 IDE,  that would be pretty simple.   Let see.

In part 3 of the Simple MCU Programming,  we access the EEPROM – AT24C16   which is an  I2C controlled.  Using the same program of I2C,  we can used it to access the TDA7449   or any I2C  component.

In Part 3 of Simple MCU Programming,  page  203 – the PDL  (Program Description Language)  is shown  in Figure 9-10.   In here,  the AT24C16 EEPROM  can be read and written.   But in the TDA7449 – it only need to write,  means,  to send the data  for the Input select, Gain, bass, treble, volume and speaker attenuation,  there is no provision to  read the data.

Please download the TDA7449 datasheet,  it discusses of the I2C protocol on page 9.   For our usage,  we need the specification of chipset ID or Address ,  you can see it on page 10 of the datasheet,   it says,  TDA7449  ID is  88 Hex,   this is the address we specify if we need to send data to the chip via I2C.   For the AT24C16,  the Id to read is  A1 hex and the ID to write is A0 hex.

[Dandy]

I2C  control  from the AT89S52 MCU:
From the  schematic diagram of the DR100W_CM  (control Module),   MCU pin 14 is the SDA (data) and pin 15 is the SCL (clock).   This I2C assignement is shared with the AT24C16 EEPROM.

To be more specific,  the port pins are :
P3.4 =  SDA
P3.5 =  SCL

This assignment of I2C is my own assignment,  based on the NE2ss Trainer Kit design, which I simply follow.  This assignment can be changed, you can use any port of the MCU for SDA and SCL.

The SCL and SDA should be connected to the SCL and SDA of the TDA7449.    To be specific

Pin 20 =  SDA     (connect to port P3.4, pin 14 of MCU)
Pin 19 =  SCL      (connect to port 3.5, pin 15 of MCU)

Programming Language Description (PDL).
In BASCOM 8051 / AVR,  you need to declare the port,  the chip address and data to be written into the I2C device.   Let’s see the PDL to write a data to the I2C device.

PDL:
I2C PORT CONFIGURATION
SUBROUTINE DIMENSION
DIMENSION OF VARIABLES
EEPROM ADDRESS/ID  DEFINITION
DATA DEFINITION / INITIALIZATION
CALL TDA7449
SUBROUTINE


I2C PORT CONFIGURATION:
'CONFIGURATION For the MCU port of AT89S52
Config Scl = P3.5
Config Sda = P3.4


SUBROUTINE DIMENSION:
Declare Sub TDA7449(address As Integer , Writevalue As Byte)


DIMENSION OF VARIABLES:
Dim Address As Integer
Dim Writevalue As Byte


Dim TDA7449_VOLUME     as Byte
Dim TDA7449_L_SPKRattn    as Byte
Dim TDA7449_R_SPKRattn    as Byte
Dim TDA7449_GAIN       as Byte
Dim TDA7449_INselect       as Byte
Dim TDA7449_BASS       as Byte
Dim TDA7449_TREBLE      as Byte

EEPROM ADDRESS/ID  DEFINITION:
Const Addresswrite = &H88
<<<this addresss is based on the TDA7449 datasheet page 10>>



DATA DEFINITION / INITIALIZATION:
‘The following Initialization define the address of the TDA7449 parameters
TDA7449_Inselect       =  00           ‘<select input 2>
TDA7449_GAIN      =  01         ‘<gain is 0 dB>
TDA7449_VOLUME        =  02          ‘<Volume is 0 dB, max volume>
TDA7449_BASS      =  04           ‘<Bass is Flat response>
TDA7449_TREBLE      = 05            ‘ <Treble is flat response>
TDA7449_L_SPKRattn   =   07          ‘<L_Speaker Attn is 0 dB,  no attm>
TDA7449_R_SPKRattn   =   06           ‘<R_Speaker Attn is 0 dB,  no attm>


<<<See the block diagram of TDA7449, see page 5.   The address is shown on  page 10.  The data is shown o page  11 to 13>>>>>



CALL TDA7449  SUBROUTINE to write the data:
Here is the actual  instruction to access the TDA7449 and write the data :

Input Select  (Select Input 2):
Writevalue = 0   <this data means, selecting Input 2>>>
CALL TDA7449(TDA7449_Inselect , Writevalue)


Input Gain:
Writevalue = 0   <this data means,  0 dB.  If the data is 08, it means +16 dB gain>>>
CALL TDA7449(TDA7449_GAIN, Writevalue)


Volume:
Writevalue = 0   <this data means,  0 dB.  If the data is 07, it means  7 dB attenuation
CALL TDA7449(TDA7449_VOLUME, Writevalue)

BASS::
Writevalue = 7   <this data means,  Flat response of BASS>
CALL TDA7449(TDA7449_BASS, Writevalue)


TREBLE::
TREBLE = 7   <this data means,  Flat response of TREBLE>
CALL TDA7449(TDA7449_TREBLE, Writevalue)


SPEAKER ATTENUATION:
Writevalue  = 7   <this data means,  -7 db speaker attenuation of left channel>
CALL TDA7449(TDA7449_L_SPKRattn, Writevalue)

Writevalue  = 7   <this data means,  -7 db speaker attenuation of right channle>
CALL TDA7449(TDA7449_R_SPKRattn, Writevalue)




SUBROUTINE:

Sub TDA7449(address , Writevalue )
    I2cstart                                                  'start condition
    I2cwbyte Addresswrite                         'slave address
    I2cwbyte Address                                 'memory location
    I2cwbyte Writevalue                            'value to write at memory location
    I2cstop                                                   'stop condition
    Waitms 10                                             'wait for 10 milliseconds
End Sub


<added>

The real Program using BASCOM 8051  <I2C  part only>,  is shown as follows :
‘==============================================================
‘                                        DR100W_EQ  I2C  Program
‘                                      *** The DR100W_conCEPT ***
‘==============================================================
‘This sample program is for accessing the DR100W_EQ specific to TDA7449
‘Will use the NE2ss Trainer Board --- converted into the DR100W_CM prototype
‘Will use the same I2C definition
‘
‘by:    DR100W_Concept_Team   (DCT)
‘Author   :   Software Team
‘
‘Perform by:
‘1diyTEAM
‘August 30, 2011
‘
‘==============================================================
‘   Compiler Directives
‘==============================================================
$regfile = "8052.dat"
‘use standard 8051 core for the Atmel AT89S52

$crystal = 12000000
‘use 12 MHz Crystal


‘==============================================================
‘   CONFIGURATION / DECLARATIONS
‘==============================================================
Config Scl = P3.5
Config Sda = P3.4

Declare Sub TDA7449(address As Integer , Writevalue As Byte)

Dim Address          As Integer
Dim Writevalue          As Byte

Dim TDA7449_VOLUME     as Byte
Dim TDA7449_L_SPKRattn    as Byte
Dim TDA7449_R_SPKRattn    as Byte
Dim TDA7449_GAIN       as Byte
Dim TDA7449_INselect       as Byte
Dim TDA7449_BASS       as Byte
Dim TDA7449_TREBLE      as Byte


‘==============================================================
‘   DATA INITIALIZATION
‘==============================================================

Const Addresswrite = &H88   ‘address of TDA7449   {write address}

TDA7449_Inselect       =  00           ‘<select input 2>
TDA7449_GAIN      =  01         ‘<gain is 0 dB>
TDA7449_VOLUME        =  02          ‘<Volume is 0 dB, max volume>
TDA7449_BASS      =  04           ‘<Bass is Flat response>
TDA7449_TREBLE      = 05            ‘ <Treble is flat response>
TDA7449_L_SPKRattn   =   07          ‘<L_Speaker Attn is 0 dB,  no attm>
TDA7449_R_SPKRattn   =   06           ‘<R_Speaker Attn is 0 dB,  no attm>



‘==============================================================
‘   MAIN PROGRAM
‘==============================================================
‘Input Select  (Select Input 2):
Writevalue = 0   ‘<this data means, selecting Input 2>>>
CALL TDA7449(TDA7449_Inselect , Writevalue)


‘Input Gain:
Writevalue = 0   ‘<this data means,  0 dB.  If the data is 08, it means +16 dB gain>>>
CALL TDA7449(TDA7449_GAIN, Writevalue)


‘Volume:
Writevalue = 0   ‘<this data means,  0 dB.  If the data is 07, it means  7 dB attenuation
CALL TDA7449(TDA7449_VOLUME, Writevalue)

‘BASS::
Writevalue = 7   ‘<this data means,  Flat response of BASS>
CALL TDA7449(TDA7449_BASS, Writevalue)


‘TREBLE::
TREBLE = 7   ‘<this data means,  Flat response of TREBLE>
CALL TDA7449(TDA7449_TREBLE, Writevalue)


‘SPEAKER ATTENUATION:
Writevalue  = 7   ‘<this data means,  -7 db speaker attenuation of left channel>
CALL TDA7449(TDA7449_L_SPKRattn, Writevalue)

Writevalue  = 7   ‘<this data means,  -7 db speaker attenuation of right channle>
CALL TDA7449(TDA7449_R_SPKRattn, Writevalue)

Do
Loop
‘This will keep the program running


‘==============================================================
‘   SUBROUTINE
‘==============================================================
Sub TDA7449(address , Writevalue )
    I2cstart                                                  'start condition
    I2cwbyte Addresswrite                         'slave address
    I2cwbyte Address                                 'memory location
    I2cwbyte Writevalue                            'value to write at memory location
    I2cstop                                                   'stop condition
    Waitms 10                                             'wait for 10 milliseconds
End Sub

‘==============================================================
‘  END of PROGRAM
‘==============================================================
End

[Dandy]

Bring-up test for the DR100W_EQ_specific to TDA7449 test, controlled by the DR100W_CM protoype :

Here is the Test Setup block diagram


The DR100w_EQ_prototype <focus the testing on the TDA7449> :


DR100W_EQ_prototype is being controlled by the DR100W_CM_prototype


Electrical performance test during the bring-up test

Using the I2C routine discussed above  (software for the I2C controlled),  the test is carried only for the TDA7449

Signal Test,  Output versus Input

The upper waveform (yellow)  is the input and the  lower waveform (blue) is the output.  This waveform is taken with the following conditions:

Select  Input 2
Select Gain = 0 dB
Volume  =  0 dB
Bass = 0 dB
Treble = 0 dB
Speaker attenuation =  0 dB
The above condition is called Flat response.

The maximum signal input with the output clipping :  input = yellow,  output = blue 



Let see the effect of Volume control,  if any distortion when the volume is decreased.

It looks not,  thus the digital volume control do not alter the signal waveform, it just reduced the signal strength.

[Dandy]

<<<Reserved for TDA7449 Bring Up Test>>>

[Dandy]

The final stage of the Bring-up test  is to integrate the PT2389  + TDA7449 + LM317  all together working as  "team" and function as DR100W_EQ, in conjunction with the DR100W_CM.

Following the block diagram  Test Setup shown above,  combining the performance of the PT2389 and TDA7449,  we can see from this Input versus Output waveform :

 

At Flat response,  we can see that, there is a low frequency loss (cut) of the output signal (blue waveform)  as compared to the input signal (yellow waveform),  this is caused by the PT2389 as shown previously.

All other waveform is the same since, like Rock, Pops, Classics, Jazz, BassBoost and 3D…….. since the TDA7449 do not alter the waveform..  Thus, whatever the characteristics of the EQ (PT2389)  shown previously is the same after integration with   the TDA7449.




let’s Test  the DR100W_EQ + DR100W_CM  Functionally.  The Test Setup Block Diagram is shown below :


screen shots :


Music Source :   MP4 Player
Power Amp   :   Digital Class T Power Amplifier

Here is the updated MMI --- changed the display to include the EQ, Bass Boost and 3D, along with the Volume Control Attenuation level (well, this is just a temporary MMI just to make the displaying better and more interactive to the USER).



Display:
Project Name  :   DR100W Power Amp  
Time              :    00:08:22     <24 hour format   >
EQ                 :  Rock
Bass Boost    :  ON  
3D Sound     :  Off
Volume Left  : -33 dB
Volume Right :  -33 dB

Note:
It is intended that, the Volume L and Right  can be adjusted individually  on the MENU – this is for Balance Purposes.   << the MMI for the MENU is not yet created>>


BTW,  I should say the importance of using “TAPE”, to secure (fixed) the wires during testing.  Some failure or breakdown happened (sometimes)  because of the wires were moved or losses  its connection to the board during the test.

[Dandy]

DR100W_Systems Bring up Test  <edited to complete the test item>
Integration of DR100W_EQ +  DR100W_CM  prototypes  using single Power Supply.

Current Consumption Test :
System  active system Flat response, LCD ON     =  90~95 mAmp
System  active system Flat response, LCD OFF    =  90~95 mAmp
System  active system, Rock, BB On,  LCD ON      =  99~102  mAmp
System  active system, Rock, BB On + 3D,  LCD ON      =  104~107  mAmp
System Standby Mode, LCD ON   =    63 ~ 66     mAmp
System Standby Mode, LCD OFF  =    33 ~ 36   mAmp

[Dandy]

Other friend (team mates) visit the lab with the new toy - - -  the  TDA8920BTH  100Wrms/channel  digital Class-D power Amplifier,  tested it and hook up into the DR100W_EQ and DR100W_CM.

Some shots :  
Integrating the  TDA8920 digital Class D power  Amp to the DR100W_CM and EQ :





Nice to hear the music…..!!!!   I am not so sure,  if it is a psychological,  that,  the EQ we design is better sounding than my other audio gadgets      .   I guess, you have to experienced it.




The TDA8920B  Digital Class D  Power Amplifier – solo Test


The music is clean, ………. Nice one…!  But  it  really need  a Tone Control or Equalizer to bring a real music quality.   Well,  the DR100W_EQ Module is one gadget  that can be integrated.


Let’s see how much power you can deliver to the load.    

If this Amplifier is Ok,  it can be a candidate for the DR100W_PA Module….  It can directly replaced the TDA8923 ---  both amplifier has its own on-board Speaker Protector,  making the DR100W_Concept  simplier  to Implement and cheaper, since the DR100W_PM  (Protection Module)  will be eliminated.     Note,  the DR100W_PM  is basically to protect the Speaker from general overload,  clipping, over voltage,  which damage the Speaker.    In the TDA7293 design  (Linear Amp )  and  this TDA8920BTH (digital Amp)  comes with the Speaker Protector.

Oh …!!!!   Technically speaking, the DR100W_Concept  was re-design to  be integrated to any Power Amplifier,   discrete, IC or vacuum Tube…..  the key point  is how to design the Protection Module  (DR100W_PM)  to allow universal Integration, including SE and BTL mode ---- so that our expensive speaker systems is always protected from being overloaded which tend to destroy it.

[Dandy]

Here is the general update for this Project :

@ LSPDS2 Prototype Stage,   the Team were able to make a handmade Prototype, integrating all the intended 4 modules :
-   EQ   :  Equalizer  
-   PA   :  Power Amplifier  
-   PM,  :  Protection Module
-   CM   :  Control Module

Here is a demo setup.




 

You may noticed the “joystick” on the universal pcb – just try to add and see its functionality  - -   this will replaced the 5 keys as :

Menu Key
Select Key  / EQ Select
Up Key / Volume Up  / Bass Boost On/Off
Down Key / Volume Down,  3D On/Off,   and
Power On / Off


Protection Module:
Currently being test for speaker overload, only work so far on  SE Power Amplifier.  {we originally intend to monitor the clipping level  with the use of  TDA7293 Power Amplifier which has a port for clipping monitoring,  but not all Power Amplifier have this diagnostic facility, to monitor the clipping level externally is still on research.}  The overvoltage is – at least working , +/- 0.9~1.3V detection,  if this range of voltage  is detected, the speaker is disconnected from the Power Amplifier.  The DR20W dc output voltage is  about 10~15 mV.

Power Amplifier:
It was demonstrated that,  it can use existing or future Power Amplifier – preferably with Mute and Standby Control.   I have demonstrated here 3  Power Amplifiers :
++ Tripath Class-T digital Power Amplifier
++ NXP TDA8920BTH Class D Power Amplifier
++ NS LM1876TF  Class AB Linear Power Amplifier   (use in the DR20W)


Control  Module:
As it is… no work done yet,  it is on debate  ----  use SMT or the  insert type components status then is To Be Advice (TBC)

EQ:
It is now on its final QA pcb design – it was modified due to the issue of standby mode current consumption,  we added a circuit to reduced the standby mode current  consumption, here is a screen shot of the pcb using Protel.






To end the Prototype stage with LSPDS2, here once again the DR100W conCEPT Prototype :

[e-tronix]

wow

[Dandy]

wow

wow!   na delay ang project.