The Zishan dsd's corner
Dec 28, 2018 at 1:54 PM Post #1,382 of 3,711
How could one of the negative channels reach a 15v positive level? And both negative outout pins are flowing

I know it doesn't seem intuitive, but you need to study the way that differential amplifiers work - since the Balanced output is driven by two pairs of differential amplifiers.
All four amplifiers have inputs that range from the (+) output voltage of the DAC, to the (-) output voltage of the DAC.
.
For the L+ and R+ amplifiers, as the signal level goes more positive, the output voltage goes more positive.
For the L+ and R+ amplifiers, as the signal level goes more negative, the output voltage goes more negative.
.
For the L- and R- amplifiers, as the signal level goes more positive, the output voltage goes more negative.
For the L- and R- amplifiers, as the signal level goes more negative, the output voltage goes more positive.
.
It's this ability to provide twice the voltage swing, across the load, that gives Balanced amplifiers their higher power output (as long as they can supply the required current).
 
Dec 28, 2018 at 3:24 PM Post #1,384 of 3,711
I know it doesn't seem intuitive, but you need to study the way that differential amplifiers work - since the Balanced output is driven by two pairs of differential amplifiers.
All four amplifiers have inputs that range from the (+) output voltage of the DAC, to the (-) output voltage of the DAC.
.
For the L+ and R+ amplifiers, as the signal level goes more positive, the output voltage goes more positive.
For the L+ and R+ amplifiers, as the signal level goes more negative, the output voltage goes more negative.
.
For the L- and R- amplifiers, as the signal level goes more positive, the output voltage goes more negative.
For the L- and R- amplifiers, as the signal level goes more negative, the output voltage goes more positive.
.
It's this ability to provide twice the voltage swing, across the load, that gives Balanced amplifiers their higher power output (as long as they can supply the required current).

Thanks for explaining to me, didn't know this, will read more on this subject
 
Dec 29, 2018 at 12:12 AM Post #1,385 of 3,711
Anyone have info on how to contact the zishan? I made the mistake of sliding the board out of the case ion the zishan 4497 in the wrong direction and ended up ruining the lcd screen. Trying to figure out if they have replacement upper board with the lcd attached or replacement lcd alone.
 
Dec 29, 2018 at 1:44 AM Post #1,386 of 3,711
Anyone have info on how to contact the zishan? I made the mistake of sliding the board out of the case ion the zishan 4497 in the wrong direction and ended up ruining the lcd screen. Trying to figure out if they have replacement upper board with the lcd attached or replacement lcd alone.

I've not seen anyone post any contact info here, just links to the Firmware downloads.
You may find someone on the Walnut and Zishan Enthusiasts Facebook group, who might be able to contact someone within Zishan - https://www.facebook.com/groups/WalnutandZishanEnthusiasts/
 
Dec 29, 2018 at 2:02 AM Post #1,387 of 3,711
So, my understanding is that DSD Pro has high output that makes it a bad match for high-sensitivity IEMs [eg. DM6]. How bad does it sound? Could you use a stock 4497 and a pair of DM6 and have a good experience?
 
Dec 29, 2018 at 8:43 PM Post #1,389 of 3,711
you mean the modified version with 2xopa275 replaced with 2xAD8620 and other caps, and voltage of opamps cranked up from +/-9V to +/- 12V?

No idea what output impedance is
 
Dec 29, 2018 at 9:04 PM Post #1,390 of 3,711
IMG_0028.PNG
 
Dec 30, 2018 at 2:49 AM Post #1,393 of 3,711
If you guys want measurements, try player.ru and use translate, it's all there, the impedances of each version, the best mods, and opamp combos, eastern Europe has alot of engineers and technicians, more than most countries so it's easier to find that info from them. Ak4497 ( standard and pro) 100ohm if you want lower impedance then the ak4490 version is said to be low, but I can remember off the top of my head, either 2.2 or 22 ohms
 
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Dec 30, 2018 at 2:58 AM Post #1,394 of 3,711
If you guys want measurements, try player.ru and use translate, it's all there, the impedances of each version, the best mods, and opamp combos, eastern Europe has alot of engineers and technicians, more than most countries so it's easier to find that info from them. Ak4497 ( standard and pro) 100ohm if you want lower impedance then the ak4490 version is said to be low, but I can remember off the top of my head, either 2.2 or 22 ohms
Thanks for the advice!
 
Dec 30, 2018 at 2:58 AM Post #1,395 of 3,711
I have both the ak4490 and ak4497 versions, the ak4490 version works great with all my kz iems and low impedance gear and the ak4497 for my high impedance gear
 

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