[therealbene]

I have an 4499 Zishan.

I read somewhere in this thread that the digital board supplies 3.3v to power the entire analog board (to MP1542). If that's the case, we're basically regulating from battery's V+ down to 3.3V before it's regulated up by the MP1542.

Is it possible to connect the 3.3v from the digital board to the base of an NPN transistor, which connects V+ directly from the battery (emitter) to the analog board (collector)? It will probably result in cleaner supply voltage, in my (very) limited understanding. Please share what you think.

 

[Merlin-PT]

I have an 4499 Zishan.

I read somewhere in this thread that the digital board supplies 3.3v to power the entire analog board (to MP1542). If that's the case, we're basically regulating from battery's V+ down to 3.3V before it's regulated up by the MP1542.

I don't have that model, but I'm sure it's not like that, as you say it wouldn't make sense.
The 3.7V from the batt go to 3.3V LDOs and DC-DC converters.
The 5V LDO gets the voltage from the 5.xxV DC converter.

 

[fressi2110]

this is newest DSDs firmware, tried very hard to sign up a baidu account

 

[powergeek]

this is newest DSDs firmware, tried very hard to sign up a baidu account

Thank you

 

[londere]

Translated change log from 0.5c:

0.5c update log:
1. Modify the playback interface up and down keys and long press the volume increase and decrease
2. Increase CS43198 support

and many more

What else needs to be done:
1. Long text scrolling in the playback interface
2. Reduce the noise of 4499 DSD cut songs

and many more

 

[Themilkman46290]

 

[moshe tes]

Translated change log from 0.5c:

0.5c update log:
1. Modify the playback interface up and down keys and long press the volume increase and decrease
2. Increase CS43198 support

and many more

What else needs to be done:
1. Long text scrolling in the playback interface
2. Reduce the noise of 4499 DSD cut songs

and many more

In my opinion the main thing that needs to be done is to enable track reverse. I think the rest of the player is fine, but that feature alone is a deal breaker.

 

[moshe tes]

this is newest DSDs firmware, tried very hard to sign up a baidu account

Does this firmware apply to AK4497 DSD?

 

[londere]

Does this firmware apply to AK4497 DSD?

Tested on DSD's AK4499 and GAD Dual AK4497.

 

[moshe tes]

Latest iteration. Not yet done. I'm still going to add OPA1622 as buffer.

 

[Merlin-PT]

@moshe tes
Although I clean my PCBs after soldering and they look clean, sometimes there was excessive sibilance or harshness in music that wasn't there before.
When inspecting with a cheap plastic microscope there was still salts from JBC liquid flux I used or grease from mechanic UV80 flux, deposited between smd components and the PCB or between dac/opamp legs. The opamps, their components and dac where the problematic contaminated areas for sound.
After cleaning it again with Isopropyl alcohol (or in worst cases with pure acetone) and let it dry, the problem went away. I use coton swabs (Q-tips) and a small gentle brush that can go between ICs legs and smds. Sometimes I needed to clean more than once what looked already clean.
So don't forget to clean the PCB, depending on the flux it can affect sound.

 

[moshe tes]

@moshe tes
Although I clean my PCBs after soldering and they look clean, sometimes there was excessive sibilance or harshness in music that wasn't there before.
When inspecting with a cheap plastic microscope there was still salts from JBC liquid flux I used or grease from mechanic UV80 flux, deposited between smd components and the PCB or between dac/opamp legs. The opamps, their components and dac where the problematic contaminated areas for sound.
After cleaning it again with Isopropyl alcohol (or in worst cases with pure acetone) and let it dry, the problem went away. I use coton swabs (Q-tips) and a small gentle brush that can go between ICs legs and smds. Sometimes I needed to clean more than once what looked already clean.
So don't forget to clean the PCB, depending on the flux it can affect sound.

Hey you just answered a question before I even asked it. I am having a problem with the left channel outputting a loud hissing and squeaky noise. I measured 4.5v dc on the 3.5mm ouput. I see the theme of cleaning the pcb repeated over and over again as I try to figure out the problem.

 

[oneula]

My DSD still amazes me with it's sound quality and power output especially when its only playing DSD tracks
Seems like they were really made for each other

 

[Merlin-PT]

Hey you just answered a question before I even asked it. I am having a problem with the left channel outputting a loud hissing and squeaky noise. I measured 4.5v dc on the 3.5mm ouput. I see the theme of cleaning the pcb repeated over and over again as I try to figure out the problem.

From your description that could be something more.
So I looked at your photo (don't know if it's the last changes) but there you forgot to close one of the opamp loops, with a solder bridge/jumper (in the 3.5mm output opamp).

 

[moshe tes]

From your description that could be something more.
So I looked at your photo (don't know if it's the last changes) but there you forgot to close one of the opamp loops, with a solder bridge/jumper (in the 3.5mm output opamp).

I knew about the bridge. I found the issue to be that one of the lpf opamps OPA1612 for the left channel had malfunctioned and was putting out a lot of DC. I replaced both with AD8599 I had around and now I like it even better. More detailed. I think I have finally arrived at the musical nirvana or close enough to it that I was looking for.