The Zishan dsd's corner
Mar 12, 2019 at 11:48 AM Post #2,146 of 3,711
“half ESR, and shift HPF cutoff frequency down by 1 octave, which could be beneficial for low impedance earphones bass response.”

I wouldn’t do it! That’s set by DSD standards. Unless you want tonic issues on other tracks. It’s tuned that way for a reason. But maybe if you are tone deft or listen to only electronic music like drum and bass minimalism it may not annoy you but I want my music to be in the correct pitch and key.

The limits of dithering, modulator filters on the software side makes you will never be able to get it sound “perfectly” without (great) software algorithms. DSD is unstable on 1 bit and you can’t DoP on the Zishan Firmware. That’s the limit you get with DSD unless you have software with those filters baked in the firmware (like the stock manufacturing Ak4497 digital filters on the Zishan).

I’m looking to crack this problem and others a. Getting the filters on the firmware b. Embedding them In the files themselves.

This requires conversion software and a DSD dac via USB A to listen for sibliance, etc on low impedience headphones.

With great digtial filter FX you can expect more transient music without harsh frequencies when it’s done right.

DXD thats is 384 are up in PCM sounds great too with these conversions. They are also recognized by Native DSD. However don’t sound great on the Zishan. I would imagine the Sable chip DACs it’s does??

It may be more beneficial as a mod to look at running the board on an open source motherboard.

Updated: Been Op Amp rolling lately and I just picked up an ADA4637 as recommended by someone on the forum. Like the Opa637 it’s set at +6 dB in gain and since my files are set at -6db to -12db I’m allowing the amp and my low impedience to power them and it sounds better with not harsh frequency. It’s worth experiencing sans making a big hardware mod commitment.

Especially what you trying to do is align your specific rig to what sounds best!

(As a side note now have also the LDOs and oscillator for the electronical mods mentioned on this thread. Awaiting my hot air station with 15 hot air tips!)
 
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Mar 12, 2019 at 2:30 PM Post #2,148 of 3,711
Did anybody test this...?

i had asked some time ago for similar chinese opamps (in opamp thread)
https://www.head-fi.org/threads/the-opamp-thread.432749/page-377#post-13610281

and got these replies;

My guess is they are fakes. HDAM is an acronym for - hyper dynamic amplifier module - a term used by Marantz to describe their pre opamp circuits. SS3601/2 is a Sparkos designation for their opamps. And the PHILPS at the bottom does not inspire any more confidence. Most likely rebranded 49720/49710HA if you are lucky. Maybe something crappier. If they were legit and good there would be more info out there.

The AMP9920AT is very funny stuff, it's a cheapo SOIC8 chip(5532 IIRC) fitted in a T099 case at premium price, you can find pics of it being cracked open on google.

It's your lucky day, PM search finally works again so here goes: https://www.jdbbs.com/thread-5699748-1-1.html
rofl.gif
 
Mar 12, 2019 at 2:37 PM Post #2,149 of 3,711
Mar 12, 2019 at 3:04 PM Post #2,150 of 3,711
i had asked some time ago for similar chinese opamps (in opamp thread)
https://www.head-fi.org/threads/the-opamp-thread.432749/page-377#post-13610281

and got these replies;
I hate fakes, but in some convoluted way, I enjoy seeing this type of fakery. So much effort to try and get you to plunk down $45 only to be completely pissed off (if indeed it sucks). Complete ballsy griftering brings some facet of entertainment for me...unless I was the one who bought one! Hahah
 
Mar 12, 2019 at 3:23 PM Post #2,151 of 3,711
I have (yet another) crazy idea...
There’s a bit of output caps discussion here and lack of space is a limiting factor, so higher capacitance one’s would not fit, but capacitors could be paralleled which gives twice the capacitance (and twice the price) and half ESR, and shift HPF cutoff frequency down by 1 octave, which could be beneficial for low impedance earphones bass response.
I removed all decoupling audio caps in my DSD and there’s no coming back for me, but I don’t see too much trouble fitting x2 6.3mm capacitors in DSD. Anyone keen to give it a go?
How do you suggest fitting 2 extra capacitors? I don't mind ordering 2 extra caps, (free shipping ftw), but I don't think I can fit them.
 
Mar 12, 2019 at 3:39 PM Post #2,152 of 3,711
How do you suggest fitting 2 extra capacitors? I don't mind ordering 2 extra caps, (free shipping ftw), but I don't think I can fit them.
In my experience 6.3mm caps fit between the boards (just), provided there’s no tall part on opposing digital board. I would place them on either side of DIP8 socket or between the DIP8 socket and the edge of the board (where balanced output resistors are), adding wire and heat shrink, obviously they have to be soldered to the output caps terminals.
I cannot guarantee that they will fit of course, but if you have unsoldered spare caps you can check for fit.
 
Mar 12, 2019 at 3:40 PM Post #2,153 of 3,711
In my experience 6.3mm caps fit between the boards (just), provided there’s no tall part on opposing digital board. I would place them on either side of DIP8 socket or between the DIP8 socket and the edge of the board (where balanced output resistors are), adding wire and heat shrink, obviously they have to be soldered to the output caps terminals.
I cannot guarantee that they will fit of course, but if you have unsoldered spare caps you can check for fit.
Ok, I'll check later.
 
Mar 12, 2019 at 9:27 PM Post #2,157 of 3,711
New firmware is apparently out, 0.4i
Will post link shortly.

http://s000.tinyupload.com/index.php?file_id=58360121163321967098

Changelog:
0.4I update log:
1. Reduce the crash and many more S
Still need to do:
1. Play interface long text scrolling and many more

Flashed, shuffle mode works even when album art is displayed. I may be wrong, but my DSD seems to run much colder.
 
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Mar 12, 2019 at 9:50 PM Post #2,158 of 3,711
New firmware is apparently out, 0.4i
Will post link shortly.

The only thing I'm wishing for is m3u Playlist support... :ksc75smile:
 
Mar 13, 2019 at 3:01 AM Post #2,159 of 3,711
In my experience 6.3mm caps fit between the boards (just), provided there’s no tall part on opposing digital board. I would place them on either side of DIP8 socket or between the DIP8 socket and the edge of the board (where balanced output resistors are), adding wire and heat shrink, obviously they have to be soldered to the output caps terminals.
I cannot guarantee that they will fit of course, but if you have unsoldered spare caps you can check for fit.
They fit
 

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Mar 13, 2019 at 3:05 AM Post #2,160 of 3,711
New firmware is apparently out, 0.4i
Will post link shortly.

http://s000.tinyupload.com/index.php?file_id=58360121163321967098

Changelog:
0.4I update log:
1. Reduce the crash and many more S
Still need to do:
1. Play interface long text scrolling and many more

Flashed, shuffle mode works even when album art is displayed. I may be wrong, but my DSD seems to run much colder.
I cant recall the procedure for flashing the new firmware, can anybody remember it please...?
 

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