11-24-2018, 10:00 PM
I recently purchased "ROCK64 STEREO AUDIO DAC ADD-ON BOARD" from "PINE64-STORE".
The delivered items were different from the photos posted on the store.
So I checked the items before turning on the power.
(It can be judged at a glance that the circuit diagram that is published, and the item that arrived are different.
Therefore, i can not discuss it on a circuit diagram basis)
As a result of the preliminary check, the following doubts came out.
When I measured the terminating resistors (R14/R15/R16/R17) used to drive the "pulse-trans",
its resistance value was 1Ω or less (actual measurement was about 0.3Ω).
In addition, "062" is printed on the chip resistor.
(It may be upside down "290", but I can not judge it, so I measured the value directly)
---
As another example of implementation,
We often see the use of values of several tens of ohms, for example about 50Ω.
But, I think this value of 1Ω or less is extremely small.
● Is this the correct value intended at design time ?
And
● When using it in this state does not damage rock64 itself ?
The delivered items were different from the photos posted on the store.
So I checked the items before turning on the power.
(It can be judged at a glance that the circuit diagram that is published, and the item that arrived are different.
Therefore, i can not discuss it on a circuit diagram basis)
As a result of the preliminary check, the following doubts came out.
When I measured the terminating resistors (R14/R15/R16/R17) used to drive the "pulse-trans",
its resistance value was 1Ω or less (actual measurement was about 0.3Ω).
In addition, "062" is printed on the chip resistor.
(It may be upside down "290", but I can not judge it, so I measured the value directly)
---
As another example of implementation,
We often see the use of values of several tens of ohms, for example about 50Ω.
But, I think this value of 1Ω or less is extremely small.
● Is this the correct value intended at design time ?
And
● When using it in this state does not damage rock64 itself ?
