[CopperFox]

Buying a _portable_ dap and paying a lot more for ak4499 that has 2 dacs inside, to permanently disable one of those dacs (half of the chip)....
Isn't that saying that maybe a _portable_ player with a single ak4497 should be bought instead?

The ak4497 has lower specifications in relevant sound quality indicators than the 4499. Which is run with one half on top-performing $800 desktop dacs as well. Also from the reviews I've read the 4497 version does suffer from heat issues too (I don't have first hand experience from this though) which the modded AK4499 version doesn't really have. There is also no evidence in the measurements (or otherwise) that the non-modded turbo would sound better. On the contrary.

So it sounds good and doesn't get too hot. I ordered a second one myself.

(the mod isn't really permanent as it's mostly about removing 6 components and bypassing 4. It is reversible but there's of course always some risk involved and soldering kit/skill is needed. Putting the components back would be harder than removing them.)

 

[Merlin-PT]

Thanks for your feedback, first I wanted to say I have nothing against the mod you did, I understand the reasons and compromise.

My comments are from when ak4499 was released and if it made sense to use a high end dac with a space and budget limited implementation.
I'm not implying anything, I just think it's a valid question.

The zishan ak4497 doesn't have any heat issues that I'm aware, I decided I didn't need to put any heatsink after I put the finger on top of the dac several times when running it opened with the boards separated.

Ak4499 using full chip (using the 2 dacs inside the chip) has higher sound specifications than ak4499 using only half the chip (using only one of the dacs inside the chip and the other disabled).
My common sense says the manufactures with ak4499 half DAC implementations couldn't implement the better full chip 2 dacs specs (in their price range).
I have no idea what are the difficulties in implementing this, but AK built 2 DACs inside 4499 and measures better sound specs with both dacs used and we pay for this.

Probably we can't take full advantage of those 2 dacs better specs (turbo on) in this small size budget player.
Looks like your conclusion also points to this, but moding the player with the turbo on should also be tried.
I read the user in the other forum measured better specs for the dual DAC (turbo on) with high impedance phones, but i can't read Russian in the tables he posted.

Anyway, theory aside, the only thing that will matter to me is price and which player sounds better.
I look forward to read about this or other mods and any sound comparison to other players (to know if this one sounds better or not).

 

[rhyse42]

My single AK4497 DSD is older (not 0.4L FW) and I can flash to 0.5b and back to 0.4K without issues.
I didn't test 0.5b sound or volume because my player is opened right now.

@rhyse42
When you flashed 0.5b, did you renamed the file "sapp.bin" to "app.bin" ?

One possible explanation for your problem is that they changed the screen model in your DSD and that screen is not supported in some older FW.
Strange is that the older FW 0.4b can support it, maybe at some point they removed that code for extra space.

Maybe you could try to contact the seller and ask for 0.4L FW.

Another idea is to factory reset with 0.4k FW to see if it fixes the screen and also with 0.5b to see if it fixes the volume, just in case.
Reset to factory settings: turn power off, keep pressing left button and don't release it, turn on (pressing middle button), after the screen turns on with erasing % message you can release both buttons. This will take a few seconds (+-5 seconds) and then the screen/player automatically powers off, meaning the factory reset is done.

Tried the factory resetting; I wasn't able to see it on 0.4k and it didn't fix sadly--0.5b, too, but I was able to see it resetting. Not sure how I'd get in contact because I got it from Linsoul. I might try 0.4b at this point. I remember seeing someone post the Yandex Disk for it, if anyone has the link because it was pretty hard to find and I didn't download it when I came across it xD

 

[Merlin-PT]

@rhyse42
I see in Linsoul site an email and a discord channel.
I would explain the problem and ask them the last FW version, maybe they can ask their supplier.
I msg. my aliexpress seller asking 0.4L, but I don't know what they will reply, I got my ak4497 some time ago from a small seller.

Just curious, with 0.5b If you increase the volume to 100% is that a low volume?
When you flashed 0.5b, did you renamed the file "sapp.bin" to "app.bin" ?

Looks like I misread your previous posts about a 0.4b version, sorry for the confusion about 0.4b.
I only mentioned 0.4b because I thought you said it worked, but I misread that.

 

[rhyse42]

@rhyse42
I see in Linsoul site an email and a discord channel.
I would explain the problem and ask them the last FW version, maybe they can ask their supplier.
I msg. my aliexpress seller asking 0.4L, but I don't know what they will reply, I got my ak4497 some time ago from a small seller.

Just curious, with 0.5b If you increase the volume to 100% is that a low volume?
When you flashed 0.5b, did you renamed the file "sapp.bin" to "app.bin" ?

Looks like I misread your previous posts about a 0.4b version, sorry for the confusion about 0.4b.
I only mentioned 0.4b because I thought you said it worked, but I misread that.

I was about to shoot them an email. I did rename sapp.bin to app.bin which I read about here. On 0.5b if I try setting the volume to 100% it distorts (it usually does around 80) but the volume is way quieter

 

[CopperFox]

About the stock AK4499 version overheating: In my use of mobile usb dac streaming with all highest quality settings, the dac would shut itself down after about one hour of use when the internal headphone amplifier was used. The heat would almost cause holding it in my hand to hurt, but then the liquid cooling system built into my hand would transfer the heat away.

 

[Merlin-PT]

I had read in the Russian forum that heating and power consumption was the primary reason for the user to do that mod.
The same can be done by software with turbo off. (He also removes 2 opamps to save a bit more additional power)
But (without the mod and with turbo off) you mention this and it should be investigated:
"Except that without modification the output voltage swing was +-3.7V and with the modifications it was +-11.36V, which is roughly the same as non-modded turbo."

 

[CopperFox]

Thought I'd post the normal dual AK4497 and the GAD EX OCL version so that it's easier to see their differences. The GAD EX obviously has more big opamps, loses the coupling capacitors and has larger power supply capacitors. What else is different and what are those green squares?

GAD which I believe is short for Ghost Audio DIY are an interesting brand in themselves and I'm coincidentally using my DSDs 4499's line out to a GAD ADIII portable tube amplifier which can be found here https://www.ebay.com/itm/HIFI-ADIII-portable-rechargeable-tube-bile-tube-amp-headphone-amplifier/274196935674?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m2749.l2649

Edit: I should mention that amplifier has USB charging.

 

[Merlin-PT]

The 4 green squares are capacitors, they could be connected to the opamps (replacing ceramics for a better sound) or they could be decoupling the dacs sound path to the opamps, I can't see were they connect neither their capacity, but I think it's the first option.

The bigger opamps (usually) have the same specs as the smaller ones, in the GAD they are in sockets to be replaced by the user.

The GAD looks like it has some buf634 (the 2 small opamps) without decoupling caps and the standard board has some discrete transistors instead and decoupling caps.

The GAD also has some small circuit near the relay, that could be discrete transistors, can't see well.
The GAD also has bigger power reserve caps for the opamps, like you mentioned.

I liked the ability to replace the socket opamps and the use of buffers, others will also value the lack of decoupling caps, I see a lot o people remove them.

From GAD taobao:

 

[Merlin-PT]

@rhyse42
I msg. my aliexpress seller asking 0.4L, but I don't know what they will reply, I got my ak4497 some time ago from a small seller.

I'm impressed with MissAudio AliExpress store fast reply.
I'm just any other guy that bought dsd ak4497 from them in 2018 because they had the better price.
They are asking the 0.4L FW to the manufacturer, let's see if zishan makes it available for download.

 

[rhyse42]

I'm impressed with MissAudio AliExpress store fast reply.
I'm just any other guy that bought dsd ak4497 from them in 2018 because they had the better price.
They are asking the 0.4L FW to the manufacturer, let's see if zishan makes it available for download.

Pretty cool they replied. Thanks for asking d: I tried Discord and got no reply

 

[fabien32]

So I installed the 5b on the 4497 and the sound was terrible. On the other hand the 4k is great

 

[rhyse42]

So I installed the 5b on the 4497 and the sound was terrible. On the other hand the 4k is great

I like how 0.4k sounds, too. I wish the interface would show up though xD

 

[Leonne]

I see, have you tried the newer DSDS series with the dual 4497 and 4499?

sorry im not

so you mean that possibly no low ohm issue on balanced mod?sorry for question

theoretically, yes

 

[Ivan TT]

Mouser JP tries to sell more LDOs
https://twitter.com/mouserelecjapan/status/1277210245417308160?s=21