[Merlin-PT]

Did it work in the past with that charger and cable?
Is the blue light on?

 

[stmiller]

Yes it did.

Blue light is on.

 

[Merlin-PT]

It should only do slow charging when the battery is almost full.

The only way to know how fast it's charging is to measure the current.
I bought this to measure the current of some of my USB devices, chargers and cables:
https://www.aliexpress.com/item/USB...-detector-power-bank-charger/32773261577.html
You only need the black device with screen to measure zishan charging current.
(The big green resistors gets very hot, it's normal, but don't let those connected more than a few seconds to measure. The black device with screen, doesn't get hot.)
I'm not saying for you to buy this, it won't fix the problem, but allows to know more about usb charging.

There is a chip inside the zishan, near the micro usb, that is responsible for charging the battery, it's normal for that chip to be a bit warm, but not very hot. Let's hope that chip is working well and it's not the problem.

 

[kookaudio]

Little bit off topic at the moment, but just letting you know that Nichicon KW 220uf (at least the 16v rated ones) fit in the case (with some small adjustments)
KW are ok even on signal, comparable to FG ones, and is someone is interested in more than doubling capacitance there, it works.

 

[Merlin-PT]

How's the sound, doubling the capacitance there?

 

[stmiller]

I had it switched off and charging from the usb port of my pc for about 2hrs..

It's now approx 75% full up from 25%, and doesn't feel warm.

 

[Merlin-PT]

It's working, did you use the same cable?

 

[kookaudio]

How's the sound, doubling the capacitance there?

Did not try, but someone here who removed the resistance in the output could maybe want to at least push up capacitance.
In theory should push up some bass frequence.

 

[Merlin-PT]

Yes, in theory increasing the coupling capacitance could increase bass, but only if previous capacitance was too small and was filtering it...
Because he decreased the impedance...I've read it somewhere, but I don't know the math

 

[Draknodd]

Just received the zishan 4497 kindly sold by musicday.
Short impression: I tried with 1more quad driver (32ohm, 1 DD 3BA) good detail, punchy bass that I like a lot, pleasant mids, highs are a bit weak (not a lot, just a little bit compared with the sabre on my v20), soundstage is not wide.
In conclusion v20 vs zishan:
-Detail: draw
-Bass: zishan
-Mids: draw
-High: v20
-Soundstage: v20
-"Sound impact": zishan, the presentation Is more "on your face".

Little bit off topic at the moment, but just letting you know that Nichicon KW 220uf (at least the 16v rated ones) fit in the case (with some small adjustments)
KW are ok even on signal, comparable to FG ones, and is someone is interested in more than doubling capacitance there, it works.

Now I want to start to improve my ZS, thanks for the suggestion about caps, I'll change them. Plus, I'll lower output resistors on SE out.
Now Can someone suggest me 2x opamp for LPF (instead of op275) and one opamp for gain (instead of lm4572) to achieve a sound more open, with more detail and wider soundstage (without losing those awesome bass freq.s)?
Thank you very much

 

[kookaudio]

ADA4637 instead of the lm4572 should do the job.
2 of them of course.

 

[Themilkman46290]

I haven't modded mine yet, but I have asked many people, on here and in Russian forums, most people recommend ad8620 for op275, and preference changes on what to change the lm4562, I am waiting until I can find a friend to buy abroad because locally they cost $30

 

[kookaudio]

Ad8620 can be brought on ebay for about 10$ from reliable sellers like joaoccabral and others like tevatronix.
Of course you can buy for much, much less, but you will never know if they are actually legit.

 

[kookaudio]

Just received the zishan 4497 kindly sold by musicday.
Short impression: I tried with 1more quad driver (32ohm, 1 DD 3BA) good detail, punchy bass that I like a lot, pleasant mids, highs are a bit weak (not a lot, just a little bit compared with the sabre on my v20), soundstage is not wide.
In conclusion v20 vs zishan:
-Detail: draw
-Bass: zishan
-Mids: draw
-High: v20
-Soundstage: v20
-"Sound impact": zishan, the presentation Is more "on your face".




Now I want to start to improve my ZS, thanks for the suggestion about caps, I'll change them. Plus, I'll lower output resistors on SE out.
Now Can someone suggest me 2x opamp for LPF (instead of op275) and one opamp for gain (instead of lm4572) to achieve a sound more open, with more detail and wider soundstage (without losing those awesome bass freq.s)?
Thank you very much

What are you going to do with the resistors?
What values?
What kind of res?

 

[Themilkman46290]

Yeah I know, and through certified ad sellers it's like 13-15 for ad8620 but none ship to this country, allot of eBay guys don't sell or ship here also, and there is no way to get it in my country, and besides that, our national post office is known to "lose" allot of packages containing anything related to technology, (i lost 3 out of 5 packages from 11/11)and honestly people here have a bad reputation for being dishonest buyers and sellers so I don't blame eBay sellers that refuse to send or sell to people here. So I will wait patiently, until I have all the right parts then mod it