Dual Mono DAC AK4490/AK4497

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Hello, i need some help!!
o bought the diyinhk 4497 board. yesterday soldered the components but not the opamp section since i´m using the diferential signal only.
i´m using the hifiberry dac pro i2s but i have no sound.
i ve been using hifiberry dac pro i2s with other 3 different boards ak4495 that i bought from ebay without any problems...

on the diyinhk board i connect 2 power supplyes- one 5 v and other 3.3v.
i checked with the multimeter and i get on:

c22- 5v
c21 - 5v
c18 -3.3v
c17 - 3.3v
c23 - 1.8v
everthing seems ok...

can you someone help me?? how can i measure other things to see where the problem is????

on the output i have 2 mundorf caps on the r+ and l+ from the dac out and the earth connected to analog ground as usualy do on the other boards. and i have sowter transformers to connect... (i´m only using caps for testing to see if dac works)

i checked if the i2s pins are shorting each other but they are not and are correct soldered.
 
How does it sounds in commparisson to other dacs that you have tried...ak4495,ak4490?
Maybe picture of finished board. To see which type of capacitors did you used.
thank you.
I will post pictures soon. I have to put everything right. I only tested with a cheap linear supply on the 5v side and 3.3v on the digital. I have supllies from salas to mount and test.
I have to connect the transformers too.
I used caps from dyinhk but changed the two analog vref 2200uf to nichicon fine gold (it was what i had at hand).

As for the sound i think its the same type of sound of 4495seq.. dynamic strong and clean bass and highs. I think it is a little better , stronger and more cleaner...the sound has a lot of power...
 
Not many people building this DAC so I thought I would share my experience. I have separate super regulated power supplies for the Analogue 5V and the analogue 3.3V. Separating out the Digital 3.3V was not a huge subjective difference in SQ. However running the Analogue voltage at 6.8V was miles better. More clarity and density to the sound.
I am currently using the same filter/ buffer circuit as the evaluation board with different resistor and capacitor values. In terms of op amps I have tried various including LM49990, LM47910, AD4489 etc The cleanest sounding is LM4990. However the one that I am using is a current feedback Plano - LM49713. The high output current and slew rate makes a big difference. Best clarity and bass response too! I would say that this chip is equal to or better than the Sabre ES9018[emoji846]


Sent from my iPhone using Tapatalk

Have you tried using 7.2v ?
 
I am currently using the same filter/ buffer circuit as the evaluation board with different resistor and capacitor values. In terms of op amps I have tried various including LM49990, LM47910, AD4489 etc The cleanest sounding is LM4990. However the one that I am using is a current feedback Plano - LM49713. The high output current and slew rate makes a big difference. Best clarity and bass response too! I would say that this chip is equal to or better than the Sabre ES9018[emoji846]


Sent from my iPhone using Tapatalk

Are you using balanced output ?
 
Have you tried using 7.2v ?



I wasn't brave enough! I like to leave a bit of margin as I am not sure about the presence or otherwise of switch on/off transients in my home made discrete regulators. If you are using monolithic chip regulators which have been well tested and analysed, I would definitely go for it as the pay off is likely to be quite good.


Sent from my iPhone using Tapatalk
 
Have you tried using 7.2v ?

I wasn't brave enough! I like to leave a bit of margin as I am not sure about the presence or otherwise of switch on/off transients in my home made discrete regulators. If you are using monolithic chip regulators which have been well tested and analysed, I would definitely go for it as the pay off is likely to be quite good.


Sent from my iPhone using Tapatalk

Just to clarify, you are referring to AK4490 (which will run up to 7V analog
supplies) here and not the latest AK4497 which will most likely be damaged
by such voltages.

T
 
How is lme49713 output schematics look like. I have used lme49990 because it was most neutral very close is AD that Sonny recomendet. Best was ccda tube out. And i will like to improve it some more. Analog supply was 6.1V because of 6.3v FP capacitors.



See this thread

https://r.tapatalk.com/shareLink?ur...hare_fid=10716&share_type=t&share_pid=4720286

The main thing is that the LME49713 is a current feedback op amp and this can be a drop in replacement for a voltage feedback op amp provided there is no capacitance connected to the negative input especially in the feedback loop.


Sent from my iPhone using Tapatalk
 
Hi, i see that your taste is the same as mine ...identical opamps were also the best ones at my configuration.
i can*t see lme49713 schematic... sorry for my blindness. Can you put it here?
Thank you very much.



You can use the LME49713 instead of the op amps shown in most of the schematics on that thread (provided there is no capacitance connected to the op amp inverted input pin)


Sent from my iPhone using Tapatalk
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.