bru87tr
100+ Head-Fier
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- May 21, 2016
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Sounds like your in the wrong thread.
Powerful how?You sir, you’ve given me the courage to purchase the KA17(when the time is righ) even though i own the world‘s most powerful dongle( for its size)! That dongle is also in your picture, take a guess![]()
Doesn't ru7 have less power output?
He was just guessing. I'm pretty sure that's not the most powerful dongle when compared to flagship dongles like the DC Elite and KA17.Doesn't ru7 have less power output?
There seems to be some confusion with your units when you write mA but it is actually A (e.g. about 0.28 A draw from the external power as your usb-meter in the picture shows and not 0.28mA) otherwise the measurements do not make sense. Also the output power is not fitting. Additionally a typo with the numbers creeped in at
Here are some number for those who like to see some actual measurements of power-draw / output power. It is a bit tedious so I only measured the 3.5mm single-ended output, 47ohm dummy load with matched output to 0.095V (or otherwise vol 30/60 in normal mode and 27/30 in desktop mode). Note that my Sony Xperia, as mentioned previously, doesn't limit its Type-C power so it can, without external power, power the KA17's desktop mode. This is why you don't see any major difference between the results, with or without external power (which is a USB wall adapter that supports PD / QC / various power profiles).
Without External Power
SE: 5.18V 0.21mA = 1.1W (Vol30)
Output: 0.095V 12.7mA = 1.21mW
SE(D): 5.18V 0.30mA = 1.5w (Vol27)
Output: 0.095V 12.9mA = 1.23mW
*The first line is the power draw, and the second line is the 3.5mm output power. The next two lines are the same but in desktop mode.
With External Power
SE: 5.19V 0.03mA = 0.16W | 4.95V 0.18mA = 0.89W (Vol30)
Output: 0.095V 12.9mA = 1.23mW
SE(D): 5.19V 0.30mA = 0.16W | 4.94W 0.28mA = 1.38W (Vol27)
Output: 0.095V 12.9mA = 1.23mW
*The first line is the smartphone's power draw + the external USB power draw, and the second line is the 3.5mm output power. The next two lines are the same but in desktop mode.
As you can see, there is a small difference between normal vs. desktop mode. It might not be as big as one might think but my guess is because my Sony Xperia just doesn't care much about limiting power so KA17 is fairly well-powered either way, thus the difference isn't as noticeable. But there is however a noticeable listening difference for me personally, desktop mode provides just a little sharper image, tightness, and control even when volume matched.
assuming that it is also 0.03 A (!) so that the indicated power is correct, it matches my measurements where in external power mode there us practically no draw from the OTG host and almost all power comes from the external supply if that delivers sufficient power. The remaining small difference (in my case the draw from the host was below 0.01A ) seems to depend on the host device or on the external power supply (yours is below 5V…?).SE(D): 5.19V 0.30mA = 0.16W
You are correct, some of the mA should be A. I rushed to post on the morning before I went to work so I copied and pasted all the same unit (*my original note doesn't have unit) without thinking straight. The other are just typo. Will correct soon.There seems to be some confusion with your units when you write mA but it is actually A (e.g. about 0.28 A draw from the external power as your usb-meter in the picture shows and not 0.28mA) otherwise the measurements do not make sense. Also the output power is not fitting. Additionally a typo with the numbers creeped in at
assuming that it is also 0.03 A (!) so that the indicated power is correct, it matches my measurements where in external power mode there us practically no draw from the OTG host and almost all power comes from the external supply if that delivers sufficient power. The remaining small difference (in my case the draw from the host was below 0.01A ) seems to depend on the host device or on the external power supply (yours is below 5V…?).
210mA current draw seems pretty high for a usb dongle! @twister6 measured 150mA only for DC-elite (albeit DC-elite has lower output and the measuring condition not clear). i measured my own L&P W2 before (which has a reputation of being power hungry) only needs 120mA. i was thinking to buy KA17 but now probably will wait and see more feedback on the power consumption before making decision . . .
Here are some number for those who like to see some actual measurements of power-draw / output power. It is a bit tedious so I only measured the 3.5mm single-ended output, 47ohm dummy load with matched output to 0.095V (or otherwise vol 30/60 in normal mode and 27/30 in desktop mode). Note that my Sony Xperia, as mentioned previously, doesn't limit its Type-C power so it can, without external power, power the KA17's desktop mode. This is why you don't see any major difference between the results, with or without external power (which is a USB wall adapter that supports PD / QC / various power profiles).
Without External Power
SE: 5.18V 0.21A = 1.1W (Vol30)
Output: 0.095V 12.7mA = 1.21mW
SE(D): 5.18V 0.30A = 1.5W (Vol27)
Output: 0.095V 12.9mA = 1.23mW
*The first line is the power draw, and the second line is the 3.5mm output power. The next two lines are the same but in desktop mode.
With External Power
SE: 5.19V 0.03A = 0.16W | 4.95V 0.18A = 0.89W (Vol30)
Output: 0.095V 12.9mA = 1.23mW
SE(D): 5.19V 0.03A = 0.16W | 4.94V 0.28A = 1.38W (Vol27)
Output: 0.095V 12.9mA = 1.23mW
*The first line is the smartphone's power draw + the external USB power draw, and the second line is the 3.5mm output power. The next two lines are the same but in desktop mode.
As you can see, there is a small difference between normal vs. desktop mode. It might not be as big as one might think but my guess is because my Sony Xperia just doesn't care much about limiting power so KA17 is fairly well-powered either way, thus the difference isn't as noticeable. But there is however a noticeable listening difference for me personally, desktop mode provides just a little sharper image, tightness, and control even when volume matched.
It is very high for an USB dongle, but it is also kinda source dependent. Hence the reason why I mentioned that my Sony Xperia doesn't limit power draw and thus you should see 210mA as more of a worst-case scenario. For example, Using Shanling M1s as the source, the average power draw for normal mode is more or less around 5.1V 0.18A = 0.9W or so. As a comparison, DC-Elite will be around 0.8W under the same testing condition, so KA17 isn't exactly the best choice if you have no intention of using an external power source or if power saving is high on your priority list.210mA current draw seems pretty high for a usb dongle! ...