A story of mysterious interaction between a diy tda1543 dac setup and the human body.

[Bartb]

This is what a current source looks like - the top line is the +ve supply. Then you need to connect the bottom end of R72 to 0V and the collector of Q19 to the DAC's output (pin6 or 8). The resistor values shown are wrong, you'll want R71 to be 240 ohms and R72 as 33k.

Hello !
Added the current source. The sound is better yes. I also had a problem of excessive bass (or too little mid-highs) before. Now it's balanced.
And that eerie feeling of having Marc Knopfler signing in front of me...
Also rebuilding the 16x TDA1543 right now. Reduced the LM317s' output (there's two) to 6V so I can pop in the TDA1387s or use the new circuit options. If you want me to try anything let me know

 

[Bartb]

This is what a current source looks like - the top line is the +ve supply. Then you need to connect the bottom end of R72 to 0V and the collector of Q19 to the DAC's output (pin6 or 8). The resistor values shown are wrong, you'll want R71 to be 240 ohms and R72 as 33k.

Current Source Sidecar

 

[Bartb]

Yeah that's the circuit I was thinking of. Pin5 can be 8V with TDA1543, on TDA1387 you'll likely destroy the chip. If using 8V on 1543, you'll want the TL431 to set a higher voltage, about 6V.
For 16X parallel it would work too, just lower the 1k1 suitably to cope with 16*2.3mA for the current swing.

Hello !
Although I'm totaly enjoying the 1xTDA1543 with your extra circuits, I thought I'd give the 16xTDA1543 project another go.
Before I start soldering (320 points) I thought it would be wise to check a few figures.
Dacs are running @6V. Is it correct that I'm using 33k and 240 resistances for each (of 16) supplied power, same as for the single TDA1543?
For the combined output (2xBC327 and 2xTL431) I'm dividing 1k1 by 16, correct? ( ~68.75)

 

[Bartb]

The power supply becomes a bit of a problem. Especially if you leave it on 24/7. Remember TDA1543 pulls 50mA each.

In my opinion the paralleling of many dac chips is overrated. I actually get the best results with one selected TDA1543. They all sound a bit different from one another, especially different batches.

-Alex

Hello Alexandre,
you seem to have bought a few batches of different TDA1543...
I am having a nightmare buying these TDA1543s as each time they behave differently
Now I have these NXP marked TDA1543 that gives off only static!
Do you have any idea what is going on?

For instance (picture, starting from left)
First is brand new NXP and gives off static only
Second is a TDA1543/N2 (supposedly -hopefully-) selected from top 5%; But yes, I *think* it plays a bit better
Third is a Philips (?); this batch is giving me 1.2V from Vref (pin7) instead of 2.2V

 

[Alexandre]

Hi Bart

I don´t think I can be of much help on this. Mine look more or less like the attached, all of them. I don´t have that many different batches. They are all old. Never tested the NXP or the N2 selected. Mine measure 2V on the (unused) adjust pin.

Thanks,
Alex

 

[Bartb]

Hi Bart

I don´t think I can be of much help on this. Mine look more or less like the attached, all of them. I don´t have that many different batches. They are all old. Never tested the NXP or the N2 selected. Mine measure 2V on the (unused) adjust pin.

Thanks,
Alex

Hello Alex,
Thanks anyway for your reply. Will contact sellers to see what they know and will post if anything interesting.

 

[Bartb]

The power supply becomes a bit of a problem. Especially if you leave it on 24/7. Remember TDA1543 pulls 50mA each.

In my opinion the paralleling of many dac chips is overrated. I actually get the best results with one selected TDA1543. They all sound a bit different from one another, especially different batches.

-Alex

Hello Alex,
coming back to this older post...

Wouldn't the overal higher output current be an advantage in case you want to go straight to the amplifier (without preamp) ?

(And I would say there is some advantage in removing an amplifying stage..)