TDA7439 ATMEGA8
Hi
Finish the test program for TDA7439
Video Here :
VIODE OF LCD MENU
Files Here :
HEX BIN for ATMEGA8 & schematic
Hi
Finish the test program for TDA7439
Video Here :
VIODE OF LCD MENU
Files Here :
HEX BIN for ATMEGA8 & schematic
TDA7439 ATMEGA8 Error fix
Small fix in code
INPUT GAIN 0 to 15 db was wrong 🙁
change to 0 to 30db 🙂
files are updated
Small fix in code
INPUT GAIN 0 to 15 db was wrong 🙁
change to 0 to 30db 🙂
files are updated
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
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
Last edited:
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.
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
it's the same board as you can buy from tibi.
turn the volume up, and disconnoct the source you will hear hum
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
Last edited by a moderator:
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
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
Attachments
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
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
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
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
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 🙂
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,
use 7relais R/2R with "-127dB" at "0" volume level like i did
Or recalc R/2R for -127dB with 2dB step
use 7relais R/2R with "-127dB" at "0" volume level like i did
Or recalc R/2R for -127dB with 2dB step
Last edited:
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
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