[Merlin-PT]

is the side where the white box underneath it gets bolder the - side or is that the +?

I always double check the PCB paint, with the position of capacitor that was soldered in there and the meaning of it's polarity markings.

See the bellow wikipedia picture text:
In non solid electrolytic capacitors the line/mark in the capacitor identifies the negative - capacitor side.
In solid electrolytic capacitors the line/mark in the capacitor identifies the positive + side.

This wikipedia picture is worth a thousand words:
https://en.wikipedia.org/wiki/Capacitor_types#Polarity_marking

So in the photo I posted the white line in the stock solid capacitor is the positive (+) PCB pad.

Note: With circuit power on, we can also use a multimeter to find the voltage polarity at the caps legs.

 

[AxelCloris]

Please keep the discussion focused on the Zishan DSD and not one another. Thank you, everyone.

 

[nesty]

Hola, @PochoLaPantera!

#5. Replace LPF opamps. This one is tricky as there's too many options (from cheap to VERY expensive) and this will require desoldering/soldering in 4 capacitors that are placed on top of LPF opamps in addition to the opamps themsleves. I would try reseacrhing what people say about these: AD823, AD8599, OP275 (genuine/original) AD8620, OPA1688 and check what is within your budget too. I'm sure some other forum members will add their recommendations as well. Or do what I did and remove LPF circuit altogether, no need to buy expensive opamps, problem solved!

Hi @Ivan TT , on item#5, you mentioned there are four capacitors around the lpf opamps... may we know the value of these capacitors and type? thanks

 

[DBaldock9]

Hi @Ivan TT , on item#5, you mentioned there are four capacitors around the lpf opamps... may we know the value of these capacitors and type? thanks

I think he's talking about the 100uF electrolytic audio series pass capacitors, between the DAC chip and the LPF op-amps. They're the large ones that are laying down over the OP275 op-amps.

 

[calico88]

what happend if using 220uf or 470uf in this case ?
what happend to the sq ?

 

[Ivan TT]

Hi @Ivan TT , on item#5, you mentioned there are four capacitors around the lpf opamps... may we know the value of these capacitors and type? thanks

Off the top of my head they are 100uF 10V caps.
Since there is a 10kOhm resistor to ground on their output they form a HPF, cut-off frequency 0.16Hz
AK4497 evaluation board has 10uF/20k arrangement (0.8Hz cut-off frequency)
So based on this I don't believe increasing the value would improve anything sound quality wise.
Also, I believe 6.3V caps could be used here as AK4497 output is well below that voltage.

 

[calico88]

@Ivan TT,
would you repost your Mod List that has been deleted on page 152 ?
I just want to try other parts than can bring more detail.

I can see the "future"

 

[Ivan TT]

would you repost your Mod List that has been deleted on page 152 ?
I just want to try other parts than can bring more detail.

This one?
https://www.head-fi.org/threads/the-zishan-dsds-corner.826185/page-149#post-14841201

 

[calico88]

yess, why it's on page 149 ? it was #2276 page 152.
nevermind, thank you.

I'm getting parts from arrow and ae ... let the mod and the mood continues

 

[DBaldock9]

yess, why it's on page 149 ? it was #2276 page 152.
nevermind, thank you.

I'm getting parts from arrow and ae ... let the mod and the mood continues

While the Thread was locked, several pages worth of off-topic posts were purged.

Has anyone here experimented with using a pair of cascoded N-Channel JFETS, to provide Class A biasing for your op-amps? - https://tangentsoft.net/audio/opamp-bias.html
The article refers to 2N5484 / 2N5486 devices, but the TO-92 package style is obsolete now, having been replaced by the SOT-23 package (MMBF5484 / MMBF5486) transistors.

 

[Ivan TT]

to provide Class A biasing for your op-amps?

I only did a bit of research but never got as far as even ordering parts, but do consider these CRDs for biasing:
https://www.ebay.com/itm/2pcs-Semit...ulative-Diode-DO-35-NEW-V3788-CH/292893060080
I think 4.5mA will be sufficient but not too much...

 

[DBaldock9]

The list are some that I liked, but only based on stock/availability in arrow.com and size that could fit:
https://www.head-fi.org/threads/the-zishan-dsds-corner.826185/page-116#post-14773107

There are more cap brands/models recommended by others that I want to try.


@PochoLaPantera
Regarding opening the box, there's one more thing to add about the gold color buttons, they are loose, they are not fixed to any place and will fall.

If you open the box, with the buttons side up and slide the LCD screen out into the buttons direction, the buttons will fall inside the box into the LCD and scratch it.

So never slide the LCD screen out of the box in the direction of the golden buttons, the boards must go out slowly in the other direction.
Also have the buttons side facing down, so they don't fall into the board and scratch it.

This problem was reported by some users and is a great warning for all of us.


@Themilkman46290




I decided on those you see in the last photo because of small size, it's a compromise for size/capacity/price.
We need 6.3 V, low ESR, high capacity, up to 2200uF is recommend in the datasheet.
I was already happy with 1000uF, but used lower capacity (2x220uF = 440uF each side) because of size/price.
If you have space inside the box, Ivan recommends better options, because of higher capacity.
There are a few more posts after the one I quote.

Out of curiosity, what is the size of the footprint for the DAC VREF capacitors (the ones where you used 2x 220uF)?

 

[Merlin-PT]

I used 2 in parallel for each side, for a total of 2x220uF = 440uF each side:
https://www.arrow.com/en/products/t55b227m6r3c0025/vishay

I measured the PCB pads distance and PCB space before I ordered them, then I searched for a cap size in arrow that could fit the space.
From the arrow link, this cap measures:
size (mm): 3.5 X 2.8 X 1.9

The larger size is 3.5mm, that fits on top of the PCB pads, with only a tiny bit of the PCB pads still showing.
2.8mm is how tall they will be in the PCB, because they are soldered side way.
1.9+1.9 =3.8mm is the 2 caps in parallel sandwich size, this size fits without any remaining space left in the PCB.

I can't measure them now, because they are soldered, but the datasheet has all the details.
I also found much more expensive options with higher capacity that could fit the space.
The ones I got had a good price/capacity/size relation, they are "ultra low" ESR and I like the brand.

The 100uF stock cap that was there measures 3.45 x 2.88 x 1.92 mm.

The second photo here has a better view of the caps I used:
https://www.head-fi.org/threads/the-zishan-dsds-corner.826185/page-137#post-14816714

 

[504960]

Well i havent heard the r3, but i also havent heard alot of mainstream daps that can go against a modded zishan dsd, hibby r3 is more convenient i am sure, and also will play better with more low z gear. Honestly a nicely modded dsd can go against most mainstream daps in the $300 level and a really modded dsd can surely go against the $400-500 level. but this is my opinion, i have only listened to the fiio x1mkii, x3 mkiii, the x5 mkii, xduoo x10, f. Audio s1, ibasso dx50, dx90, dx120, and other zishans and walnut daps, and i felt the zishan dsd with mods put them all to shame, altho the ibasso dx90 still intrigues me (lots of mods out there)

Hi but without mods the sound of the zishan dsd ak4497 is like wich dap? Maybe in the future with more experience i will be dooing the mods!

 

[Themilkman46290]

Hi but without mods the sound of the zishan dsd ak4497 is like wich dap? Maybe in the future with more experience i will be dooing the mods!

Hard to really say, without mods i would go for ak4495 or even the ak4490 version because they have lower output impedance and go well with everything where the ak4497 really only sounds right with high impedance gear, in stock form i like my ak4490 much better with iems and heaphones like audiotechnica m50x, grado sr80e, or hifiman he4xx. The ak4497 sounds ok with the headphones i mentioned but they get a bit boomy, and distort like crazy if you go above 25-26 out of 31 on the volume, and lose out on sub bass. So if you have high z gear, go for the 4497 or or get it modded to work better with low z gear like some have done, or get the 4495 version that sounds great stock i have heard them all, and i felt 4495 and 4497 are both fantastic. But one thing i can say is if you dont have high z gear and dont want to mod then the 4497 doesnt really make sense, but then again somepeople like b.a. drivers on high z gear, and some love the boomy midbass from low z dynamic drivers on high z sources, and pretty much all heavily marketed gear that you hear about (audiotechnica, sony, fiio, campfire audio, and all iems ) will be low impedance, so a majority of gear will sound different then its supposed to, only high z headphones (beyerdynamic, akg 601,702, sennheiser hd600 and up) and high z earbuds (anything over 100ohms) will work best

As far as what it sounds similar too, well i also couldnt say, but the ak4490 is better sounding (less digital, better soundstage, seperation, and more dynamic) then the hidizs ap60ii, fiio x1mkii,shanling m1, any ipod, and basically any player in its price bracket