DAC-END R (ES9018) full assembled board

[audiodesign]

Firmware 52a (mod)

Firmware 52a (mod)

 

[audiodesign]

I have covered the USB connector's pin 1 (Vcc pin) with a tape and powered the Amanero with DAC power, it works, no removal of LDO is needed.

I don't like very well your USB solution.

I suggest cut the pcb wire, very simple.

 

[Domi_78]

Hi,
I have raised this pin of the regulator from the printed circuit board with a cutter blade.
- So, if needed, I can weld it next time and the board remain like new.

 

[randytsuch]

Hi,
I have raised this pin of the regulator from the printed circuit board with a cutter blade.
- So, if needed, I can weld it next time and the board remain like new.

I removed the part, which I now regret, yours is a better solution.

 

[i2k92]

Quanghao, can you send my dac early next week and with the latest firmware version? Thanks

 

[danny_66]

Hello,

My DAC implementation (breadboard 😉 ) was very sensitive to the mains: if I switched on/off a lamp or my soldering station I had drop outs.
So I installed a netfilter I had laying around: much better, no more dropouts.
Nice, netfilters that really do work 🙂

Regards,
Danny

 

[quanghao]

Quanghao, can you send my dac early next week and with the latest firmware version? Thanks

yes!

some day later i will ship it!
thanks you waite!~

 

[MihajloTM]

Hello

I still have problem with heat. Tryed 15 and 22 Ohm resistors instead of 10 Ohm but it is only 5 - 10 % beter.

Still not OK. Allso I have LOT of NOISE / RIPPLE on power supply lines.

Here are puctires. All is measured on JUMPERS J9 - J10 - ..... - J15 .

1.2V - L picture is with original resistor
1.2V - R picture is with 22 Ohm resistor

 

[audiodesign]

Which power supply line ? 1.2V analog ?

Do you meausre with load or without (jump open or closed) ?

 

[MihajloTM]

Here, at this jumpers while DAC is working, jumpers closed.

 

[MihajloTM]

Pictures are from all 6 jumpers measured, from left to right

 

[quanghao]

Hello

Oh, no,no

you not can big up all R 10 Ohm to 22 Ohm, you need keep all 10 ohm.

If you need down more noise , you can down the value under 10 Ohm,

You can use : 8 to 10R. Because the curent = 06 / 10 R ( r-set current )

you see??

thanks

 

[MihajloTM]

this noise is 10 x bigger than LM317 noise.

off course I want it down

will test 8.2 ohm in 5 minutes

 

[MihajloTM]

8.2 Ohm make Bigger noise = 60 mV Peak to Peak
10 Ohm = 50 mV p - p
22 Ohm make Less noise = 40 mV p - p

HEAT stays same

 

[Erlend Sæterdal]

I put mine in the basement until next year when problems are solved ---maybe ?

 

[audiodesign]

this noise is 10 x bigger than LM317 noise.

off course I want it down

will test 8.2 ohm in 5 minutes

We cannot speak of noise because each power supply have a pre regulator followed by a shunt.

You need to test the noise on output terminals not on power jump otherwise you can create oscillation on shunt.

 

[danny_66]

I put mine in the basement until next year when problems are solved ---maybe ?

Yes do that, then we're relieved of your constructive remarks 😉

 

[Erlend Sæterdal]

Yes do that, then we're relieved of your constructive remarks 😉

I have severeal ideas but cannot measure oscilations and noise. Twisted pear had similar problems and bigger caps on output helped. More then 100 uf.I am planning to use 1000 uf. I know some off you will tell it is not good on shunts. I always put more both on out and input off regulators. They have to be closer to the shunt output. I will trow the 10 uf ceramics away. Also the ceramics by the opamps is gone allready.

 

[caad]

Hello

I still have problem with heat. Tryed 15 and 22 Ohm resistors instead of 10 Ohm but it is only 5 - 10 % beter.

Still not OK. Allso I have LOT of NOISE / RIPPLE on power supply lines.

Here are puctires. All is measured on JUMPERS J9 - J10 - ..... - J15 .

1.2V - L picture is with original resistor
1.2V - R picture is with 22 Ohm resistor

Hi there

Just to verify the measurement is correct. Please make a measurement as described in this pic. This will lower the noise that is introduced by the GND wire on the Scope Probe.

What frequency is the ripple?

Best Regards
Caad

 

[audiodesign]

Power supply noise

We cannot speak of noise in the main DAC module because we have a 2 stage power supply.

A pair of LT1963 ultra low noise linear regulators create the +5V for digital section and the +5V for analog sections.

These regulators are followed by other linear regulators or hi-speed op-amp controller shunt.

All the following measurements has been created with Clio system by Audiomatica and Transit 24bit.

There is no noise on output terminal (-78dB), see file Noise_DACout, 50Hz at -82dB coming from the air.

Also if I connect the 2.2uF input cap. to the ground I see 50Hz at -82dB.

There is a little oscillation on 1.2analog shunt (about 15KHz at -36dB), see file Noise_1_2ana.

If you add a 100uF 6.3V in parallel to the 47uF smd this oscillation stop and the new measurement give -78dB.

The other shunt have no oscillation and also the 15V shunt without pre-regulator are able to eliminate any noise, (50-100Hz at -80dB).