[amb]

R1D is in parallel with T1D transformer's winding, and R9U is in parallel with the T1U's winding. The tranformer windings have low resistance.

EDIT: MisterX beat me to it.

 

[Wizik]

So I´ll test first the DAC board, then USB board and after that, if will be everything OK, than wire USB and DAC board together and test the sound ?

 

[amb]

The γ1 test procedures are all at the γ1 website "initial check" section. The only difference for γ2 is that since the γ1 board is not snapped apart, you cannot plug the two halves together to test them together. But you can use the γ2 board to do that (populate only J1-J5 first if you want).

 

[Wizik]

Ok thanks, I already read it. I checked everythink, but I´m scared plug it in the DC wallwart :-D

 

[Wizik]

Sorry for stupid questions, but can I use for example these adapter ? It´s 5V, 20W, 4A

MW-SYS1319-2005 2.1 (751-545) - GM Electronic

 

[ShinyFalcon]

The plug is too big. While it can work, it's a switching supply, and might add noise to the DAC.

I recommend testing the USB portion first. I do not think bad will happen

. The DAC board and the USB board will still receive power from the USB. Even if the USB portion does not work, the DAC portion might.

Edit: I think you're trying to follow the initial check step by step, if you don't have a DC wallwart, you can skip the steps involving it, no need to have one if you're using it with a PC. I think you're building this for educational purposes, is that correct?

 

[Wizik]

Quote:

Originally Posted by ShinyFalcon /img/forum/go_quote.gif The plug is too big. While it can work, it's a switching supply, and might add noise to the DAC. I recommend testing the USB portion first. I do not think bad will happen . The DAC board and the USB board will still receive power from the USB. Even if the USB portion does not work, the DAC portion might. Edit: I think you're trying to follow the initial check step by step, if you don't have a DC wallwart, you can skip the steps involving it, no need to have one if you're using it with a PC. I think you're building this for educational purposes, is that correct?

Yes, too, this DAC is for my school leaving exam, but then I want using it for my amp and akg K701. I don´t want using it with DC wallwalrt, only with USB connection, but I thinked from amb initial check that I need to first test it with wallwart, then with USB. So I will plug it into USB for first test ? It´s safe ?

 

[ShinyFalcon]

Yes, you can skip the first step involving the DC wallwart and go to the next step. That first step tests the functionality of U1D. If U1D fails to work for whatever reason, we can easily bypass it.

 

[Wizik]

So when I plug it into the USB port and nothing happen, then I need to do short 2-3 on JP2D yeah ?

 

[ShinyFalcon]

I didn't mean skip directly to the USB step, I meant to follow these steps next:

Quote:

2. With your multimeter set to Ohms mode (use the lowest resistance range on a manual-ranging meter), check for short circuits between the points listed below. If you read less than a few Ohms for any of these, then there is a short circuit. Carefully locate the short (such as a solder bridge) and fix it. You may use the exposed strips along each edge of the board as the GND contact. DAC board: * JP2D pin 1 and GND * JP2D pin 2 and GND * JP2D pin 3 and GND * +3.3V test pad and GND * +4.5V test pad and GND USB board: * +5V test pads(s) and GND * +3.3V test pads and GND and so on...

until you get to the USB test.

First, since you're building a y2 as well, are the y1 halves broken apart and plugged into each other? If the y1 is not broken apart yet, you will need to install the y2 board on top of the y1, but you can just install J1-J5 of the y2 board.

 

[Wizik]

I check all that points, on every from that points was high impedance (from 30KΩ to 100KΩ). So can I plug USB now?

And i don´t have y2 already finished, first I want to test y1 before completing y2. y1 is not broken apart. I wired it with 5 wires, like is in instruction.

 

[Shahrose]

remove: accidental post...

 

[amb]

Wizik, you don't need the 5 wires if you're going to use a y2. The blank y2 board with only J1-J5 installed will act as the bridge between the two y1 halves.

 

[Wizik]

I already wire it with wires, it doesn´t matter now, I plug it into USB, and everythink looks fine ! On USB board is 5V = 4,96V and 3,3V=3,29V and on DAC board 3,3V = 3,28V and 4,5V = 4,74V, looks great, I try only direct playing on my ety ER-4P and it plays Now I´m going to build y2, hold fingers for me

 

[Billyk]

Wizik, way to go!!
Hope everything turns out great for you, I was thinking about you and your school exam the other day. Let us know.