The Zishan dsd's corner
Mar 13, 2019 at 4:02 AM Post #2,161 of 3,711
I cant recall the procedure for flashing the new firmware, can anybody remember it please...?
Download, unzip in root of memory card, make sure the dsd 0.4i file is not in any folder but on the root of your sd card, slide it in, turn it on, it will flash, then take out sd and erase that file and thats it
 
Mar 13, 2019 at 4:36 AM Post #2,162 of 3,711
upload_2019-3-13_9-36-12.jpeg Which is the file to be flashed in the reader...?
 
Mar 13, 2019 at 4:40 AM Post #2,163 of 3,711
Which is the file to be flashed in the reader...?
I added both, deleted the one that was 8, 192 kb. I am sure you could just do that one, but i wanted to know what the others do, its too bad those eq settings dont work, well some do but alot dont
 
Mar 13, 2019 at 5:57 AM Post #2,165 of 3,711
Just flashed the smaller file and it worked, thanks!
Cant see any difference in a first look but I will explore more later on...
Smaller file? Strange, smaller file is still on my card, doesnt do anything. Only the larger 8,192kb file actually flashed, other file doesn't show, and the other folder is the eq
 
Mar 13, 2019 at 6:43 AM Post #2,166 of 3,711
Been playing with new firmware for a bit, no longer freezes at all, the dac filters seem to have a bit more effect (or because of the mods they may work better, not sure) and you can skip forward without freezing.

In general they fixed the biggest problem
 
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Mar 13, 2019 at 7:37 AM Post #2,167 of 3,711
If one uses google translate to translate the contents of the txt file included in the FW update (the one with the chinese name and ".txt" :)), this is what you get:

Firmware Update Guide:

1. Enter the setting interface to see if the interface displays "ZiShan DSD 0.4I". If it is, there is no need to upgrade. The firmware is up to date, close this file.
2. Get the latest firmware app.bin and flash.bin, see this article shows that you have obtained
3. Turn off the player
4. Use the card reader to copy app.bin and flash.bin to the root directory on the TF card (that is, the directory that appears after double-clicking to open the removable disk)
5. Insert the TF card with app.bin and flash.bin into the player.
6. The red text on the white background appears, and the middle button is released. The process usually takes about one minute. After successful, it will automatically shut down.
7. Use the card reader to delete the app.bin and flash.bin on the TF card.
8. Press and hold the middle button of the player to boot.
9. Go to the settings page to see the firmware version number.

How to use EQ:
Copy "180EQ" to the TF card, enter the player browser to browse the "180EQ" folder, select the EQ file to be set, press the right button to set the current EQ


0.4I update log:
1. Reduce the crash
and many more

Still need to do:
1. Play interface long text scrolling

and many more
 
Mar 13, 2019 at 8:37 AM Post #2,168 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?

Also a good idea if someone wanted to use a 220uF model/brand that doesn't fit, but paralleled 2x smaller 100uF fit.
 
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Mar 13, 2019 at 10:04 AM Post #2,169 of 3,711
“How to use EQ:
Copy "180EQ" to the TF card, enter the player browser to browse the "180EQ" folder, select the EQ file to be set, press the right button to set the current EQ”


0.4I update log:
1. Reduce the crash
and many more

Still need to do:
1. Play interface long text scrolling

and many more


I would imagine it runs more efficient. And 180 Eq is incredible. If you lower the dbs on your files, you will have more leeway in both the Digital Filters and Eq. The problems with harshness is digital clipping many don’t realize this including me since I have a weakness for power as well!

Also by lowering your dBs you can run your Zishan in “Safe Mode” and hear the overall health of the signal and if there’s ground noise. It’s interesting.

Rule of thumb: ALWAYS go lower! I’m allowing my low impedience headphones and amps as “pickups” the same way you would with humbuckles and switches/amps on a electric guitar. Same principle. I always think as a musician. The Zishan is my instrument. Lol.

I’ve been playing around with the different op amps in the Zishan between the (AD797, Opa627 & ADA4637) and I gotta tell ya I’m amazed at what these little suckers can do!


For starters, the ADA4637 is a steal for 10 bucks and can be sourced at Arrow. (Do your ears a favor and go get two!) You’ll need two of them but it’s well worth the investment for what you get back. It’s obviously successfully plagiarized from the Opa637 but at 3x less. :wink:


What’s remarkable about it, is it’s set at +6db and there’s NO distortion. None! At low volume it can pick up nuances and with hardly any noise or distortion.


My grand concept for the Zishan would be put soic to dip adapters and have three different op amps and experimenting with combination sounds the best. Objectively I have to “match” the op amps with similar performance so that it doesn’t throw of timing, pitch, etc. so the hear test will go first then a comparison with specs.


It would be SUPER cool if I had the know how to use the op amps as switches like pickups in a guitar so you can get different sounding playbacks from “clean” to “sustain” or in this case the qualities of the individual op amps! But that would require electrical knowledge to do so and have it correspond with firmware.


Ah one can dream though... [\Spoiler]
 
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Mar 13, 2019 at 11:22 AM Post #2,170 of 3,711
I would imagine it runs more efficient. And 180 Eq is incredible. If you lower the dbs on your files, you will have more leeway in both the Digital Filters and Eq. The problems with harshness is digital clipping many don’t realize this including me since I have a weakness for power as well!

Also by lowering your dBs you can run your Zishan in “Safe Mode” and hear the overall health of the signal and if there’s ground noise. It’s interesting.

Rule of thumb: ALWAYS go lower! I’m allowing my low impedience headphones and amps as “pickups” the same way you would with humbuckles and switches/amps on a electric guitar. Same principle. I always think as a musician. The Zishan is my instrument. Lol.

I’ve been playing around with the different op amps in the Zishan between the (AD797, Opa627 & ADA4637) and I gotta tell ya I’m amazed at what these little suckers can do!


For starters, the ADA4637 is a steal for 10 bucks and can be sourced at Arrow. (Do your ears a favor and go get two!) You’ll need two of them but it’s well worth the investment for what you get back. It’s obviously successfully plagiarized from the Opa637 but at 3x less. :wink:


What’s remarkable about it, is it’s set at +6db and there’s NO distortion. None! At low volume it can pick up nuances and with hardly any noise or distortion.


My grand concept for the Zishan would be put soic to dip adapters and have three different op amps and experimenting with combination sounds the best. Objectively I have to “match” the op amps with similar performance so that it doesn’t throw of timing, pitch, etc. so the hear test will go first then a comparison with specs.


It would be SUPER cool if I had the know how to use the op amps as switches like pickups in a guitar so you can get different sounding playbacks from “clean” to “sustain” or in this case the qualities of the individual op amps! But that would require electrical knowledge to do so and have it correspond with firmware.


Ah one can dream though... [\Spoiler]
I’ve been saying the same things about ADA4637 for the last 2 months, I think...
 
Mar 13, 2019 at 11:39 AM Post #2,171 of 3,711
I’ve been saying the same things about ADA4637 for the last 2 months, I think...

I thought that it would distort but it doesn’t at all. I think it just fits well for the Zishan. Op amps by a reputable sources and from the big players you can’t go wrong some may sound better than others but quality-wise AD and TI op amps are incredible! I’m in awe of their work! AD I have found are more constant in their op amps at least at the Audio grade level. TI is more universally used for things like Medical devices, etc

(Not sure it’s the same globally but growing up as kid in the states, TI was always a calculator. Who knew! Haha)

I’m curious at what the gain is set at in the stock lpf op275 and if it can be lowered! I’m willing to bet that’s what causes the bump in high frequencies. Would rather the op amps do that as their function not the DAC itself!

You can probably lower the top Caps to 100ufs as well but I’m not sure since I haven’t changed the voltage regulators. If you get a consistent output of say 12v the headphones and amps can do their magic on their own with DC power. (I’m thinking!)

...is PURE BLISS :)

[\Spoiler]
 
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Mar 13, 2019 at 12:30 PM Post #2,172 of 3,711
So gave my zs5's a listen, bass monsters, specially after the caps got changed, sounds like i hit the bass boost button. Pretty happy, now i can play my outrageously bassy, ignorant rap crap at fairly loud volume, and when i want something a bit smarter, like old psy rock or progressive rock i connect my k's samsara, and if i am feeling for something intelligent like classical then i plug my to400's and i am set.

Just wanna thank all that people i annoyed the most.
Ivan tt and david baldock, you guys gave some good suggestions.

There are a few more guys on here that help, all of you guys rock

I am happy as hell, next will be the ak4490 dsd
But i will need to read for a wile before i attempt to mod it, other then caps and opamp
 
Mar 13, 2019 at 3:19 PM Post #2,173 of 3,711
If you looking for something more radical than the caps and opamps, this photo caught my eye:
http://player.ru/showthread.php?t=180748&page=347&p=2745495&viewfull=1#post2745495

I can't read Russian, but if you look at the DAC board photo, looks like he adds linear power regulators to the opamps power supply lines (among many other things).
He removed the two 4.7uH power inductors, that were between the DC converter and the opamp power supply capacitors to get space to add what looks like 2 linear regulators. I'm guessing because I can see 2 ICs with legs there.

I noticed that in your 4490 just like in Z2 there is only one LDO (that can be replaced as we did in 4497), but maybe linear regulators could be add to the other power lines.
I have no idea if (or how much) adding linear regulators will improve sound, but they are used in power lines in better audio projects.
I found the photo interesting and was interested in this idea before I saw this, but I don't know if I'll try it. I'm sure I won't do it right now.
 
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Mar 13, 2019 at 6:34 PM Post #2,174 of 3,711
Putting the linear regulators won’t do much to sound unless it’s for an ultrasound? The noise is not audible to the human ear unless you are hearing hisses or pops? The signal is pretttty strong and those LDOs convert sooo fast that’s it’s like focusing on a mechanical problem like “Black Box” rather than firmware like in plane crashes. I wouldn’t hang out on those sites. I get warnings every thing I’ve clicked them. Just my opinion though.

Updated: Well the only noticeable difference in the stock electrical source (or whatever you call it) is that the levels aren’t always the same to power the op amps. I’m not sure if linear or voltage regulators makes all that much of a difference unless it’s what the circuit requires??? (Not my area of expertises)

As far the ak4490 not sure if it will improve the sound but it would it improve the voltage regulation powering some op amps to keep it for dipping for instance JFETS convert Dc to ac and the best ones considered by sound enthusiast like the AD797 and the Opa627 have “low drop off” isn’t audible unless you aren’t getting direct current and the required voltage to drive the amps or you running low on battery. (Turning it up to 11 only works on Spinal Tap.)

All things considered the only effect to sound would be volume drop offs is my guess. It’s like unplugging an electric guitar doesn’t effect the sound ONLY the amplification.

Voltage only powers the amps and sound is something different would be my guess. I’d check if you are getting constant voltage before making any unnecessary chsnges unless you are a electrician than you’ll know what to do from a textbook perspective. One area where the theory is practical in relations to sound.
 
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Mar 14, 2019 at 12:35 AM Post #2,175 of 3,711
adds linear power regulators to the opamps power supply lines (among many other things)
Yup, TPS7Aхх family, both positive and negative one.

These are quite low-noise (compared to DC-DC boost converter), also the way negative rail is arranged in DSD creates uneven voltage on positive and negative rails, and negative rail is only capable of delivering a fraction of current (I believe). So all in all these SHOULD make an improvement, but soldering them in place of the inductors is tricky, so much kudos to So-Hm for getting these LDO going, I would not even dream of attempting it. On the other hand capacitors (both electrolytic and ceramic) should hold enough charge/provide sufficient filtering to clean up +/- rails, so this mod may or may not provide significant gain in terms of quality.
I also note that more recent and advanced chi-fi DAP designs (IHIFI Tuner) use TPS7Aхх family LDO in a similar way, but utilise more recent/better specification QFN form factor ones.
Or you can get one of those:
https://www.ebay.com/itm/TPS7A4700-...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649
 

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