Yet another Volume controlers and source selections

[FarmTech]

Danzup, in post http://www.diyaudio.com/forums/analog-line-level/149597-yet-another-volume-controlers-source-selections-12.html#post2074525 can i just change PGA2310 with PGA2311 and change analog supply with +/-5V without change the HEX file?

Didiet

PGA2310 & PGA2311 use same software just the VOLT(+-12 & +-5) is diffrent

 

[didiet78]

Thanks Farmtech

 

[FarmTech]

TDA7439 ATMEGA8

Hi
Finish the test program for TDA7439

'ATMEGA8
'fusebit INT 8 Mhz
' LINK TO DATASHEET http://www.atmel.com/dyn/resources/prod_documents/doc2486.pdf

' ENCODER/BUTON
' Portd.0 MENU Button
' portD.1 Encoder B
' portD.2 Encoder A
' GND Encoder C
' LINK to DATASHEET http://www.sparkfun.com/datasheets/Components/TW-700198.pdf

' TDA7439
' SDA Pin 1 To Portc.4
' SCL Pin 30 To Portc.5
' 2 * 4K7 RES to pullup SDA & SCL to +5V
' LINK TO DATASHEET http://www.datasheetcatalog.org/datasheet/stmicroelectronics/4291.pdf

' LCD 16x2
' Rs = Portb.0
' E = Portb.1
' Db4 = Portb.2
' Db5 = Portb.3
' Db6 = Portb.4
' Db7 = Portb.5
' RW = GND
' Add a potmeter for contrast !!!

' FUNCTIONS
' INPUT 1 to 4
' VOLUME 0 to -56 db
' INPUT GAIN 0 to 15 db
' BASS -14 to +14 db
' MIDDLE -14 to +14 db
' TRIBLE -14 to +14 db

' MENU AUTO RESET TO MAIN menu (volume) after 3 sec

Video Here :
VIODE OF LCD MENU

Files Here :
HEX BIN for ATMEGA8 & schematic

 

[FarmTech]

TDA7439 ATMEGA8 Error fix

Small fix in code
INPUT GAIN 0 to 15 db was wrong
change to 0 to 30db

files are updated

 

[aditya]

ok
one thng can we change input 1 ... to some thing like CD, FM , USB DAC, Phone , phone as in cell phone.. for usb dac i was thinking sinc there is a pin on PCM2704 which changes state when connected to pc. than we can use that pin to check for connection to pc so no need to touch the dial for changing channel if we connect to pc

 

[Jempie]

Jempie,

LM1117DT is a low drop regulator. Use a trafo with min 6V ac - max 9V ac.

Regards,
Tibi

Ok thanks

 

[FarmTech]

ok
one thng can we change input 1 ... to some thing like CD, FM , USB DAC, Phone , phone as in cell phone.. for usb dac i was thinking sinc there is a pin on PCM2704 which changes state when connected to pc. than we can use that pin to check for connection to pc so no need to touch the dial for changing channel if we connect to pc

Done CD, FM , USB DAC, Phone and center menu select on lcd

Added Portd.3 as SSPND
activ = low (auto select USB DAC)

! Note you cant change input while PORTD.3 IS LOW

files are updated

 

[Jempie]

farmtech,

why I hear hum when i disconnect any source, i don't think it's normal
if you compare it to another preamp you will hear nothing
se it seems that the input is open that is the sound i hear.

 

[FarmTech]

farmtech,

why I hear hum when i disconnect any source, i don't think it's normal
if you compare it to another preamp you will hear nothing
se it seems that the input is open that is the sound i hear.

Hi,
I dont have this problem with my pcb setup
maybe you can show 1 picture of the insite of case
it can be lots of thinks gnd loops ect

 

[Jempie]

it's the same board as you can buy from tibi.
turn the volume up, and disconnoct the source you will hear hum

 

[iTiberius]

it's the same board as you can buy from tibi.
turn the volume up, and disconnoct the source you will hear hum

Jempie,

There are two 0 ohm resistors on the board R42L and R42R.
These are connecting VC ground to VC power suppply ground.
Normally these resistors shouldn't be connected. However, we have provided them in case you want to make a single ground star for all power sources in your design.
If these resistor are not connected, than you should search for hum elsewhere, because in this case VC is completely isolated from any power supply.

Regards,
Tibi

 

[FarmTech]

Hi Jempie,
Did you cure the hum problem ?

 

[aditya]

pcb layout for TDA7439DS

hi
made this pcb for replacing my pga2311 ( vvvvvvvery sweet chip) card, since things are modular in my amp.. i can relace the processor, amp, power filters. so even my preamp is sort of modular...

anyways just posting the pic of the pcb... let me how to improve it more.. if possible..

yes i know i should have used mkt capz.... but .... i wanted to make it small and couldnt source all the cap in same chemical family in bombay market.. anyways.. did what i could

 

[iTiberius]

For those who like to use avrdude, I have added a small how to:
http://vicol-audio.ro/img/volume-controller/VA_r-2r_volume-controller_firmware.pdf

Also more documentation is available at vicol audio : r-2r volume controller

Regards,
Tibi

 

[TBKK]

Farmtech

According to the regular r2r schematic the resistors are

R30-R40
10k 2.5k 5.8k 15k 53k 390k
R31-R41
82k 47k 27k 16k 12k 10k

If you compare link Logarithmic Attenuator Calculator

The value are different

10k 8k2 5k6 3k9. I have the Same problem as jempie

 

[FarmTech]

Hi
I did not make the electronic part of this only made some software (addons) for it
so better ask one that know more about R2R than I do

 

[TBKK]

I hate also that the volume at "0" is not really quit

 

[Pryanick]

TBKK,
use 7relais R/2R with "-127dB" at "0" volume level like i did
Or recalc R/2R for -127dB with 2dB step

 

[Jempie]

Tbbk,

I have the same problems, clinking is
reduce thanks to Pryanick.

Will try now to recalculate the resistors
With steps of 1.5 dB or 2 dB
still is not easy to make it right

 

[Pryanick]

Jempie,
the only way to do it right is do it ones in a proper way