Gamma-2 (γ2) DAC Thread

[LionPlushie]

shall wait for that. hoping to get something of similar size to the b22.

 

[K3cT]

I finally finished assembling my γ2 and everything seems to be normal and working fine except I got only 4.1~4.3V when used with USB power. Is this normal?

This thing sounds bloody amazing btw.

 

[MisterX]

it's pretty not normal for the USB voltage to be out of spec.

Is there a problem with your Y2 build that is pulling it that low or is it always that low?

 

[K3cT]

Quote:

Originally Posted by MisterX /img/forum/go_quote.gif it's pretty not normal for the USB voltage to be out of spec. Is there a problem with your Y2 build that is pulling it that low or is it always that low?

Well, actually no. It only drops to that range when I use USB port from my computer to power both γ1 and γ2. Otherwise, the voltages are normal if I use σ25. It's a bit perplexing but otherwise everything is normal, all the I/Os are working and I can play music fine. I'm just a bit worried though...

 

[pixeljedi]

Quote:

Originally Posted by LionPlushie /img/forum/go_quote.gif shall wait for that. hoping to get something of similar size to the b22.

You could just put the γ2 in a bigger case with a σ11 and a 45lb plate if it would make you feel better

 

[amb]

K3CT, sometimes a computer's USB power voltage could be a little low, but not that low. I wonder if your computer is really out of spec? Try a different computer, and perhaps a different USB cable. Some USB cables may cause voltage drops (cable too thin or too long).

 

[pixeljedi]

Quote:

Originally Posted by K3cT /img/forum/go_quote.gif except I got only 4.1~4.3V when used with USB power. Is this normal?

Are you plugging into a USB port directly from the PC or from a USB Hub connecting to the PC? I found the the Hub I use at work to be way below 5V.

 

[Draguljce]

Hi,

I just started collecting all parts for my γ2 build (d-configuration γ1 +γ2) and after all the reading I'm still not sure what to use for output coupling capacitors. Especially since BG NX Hi-Q are unavailable (i use them for AlienDAC)
Perhaps WIMA MKS2 3,3uF would be the most neutral solution. I tried nichicon muse bp and SILMIC on alien, but BG's are overall the best for me. What about SILMIC II ?

Perhaps an ultimate solution would be CK2III +γ2 without output coupling capacitors

Thus avoiding sound coloring/degrading little bastards out of the way

 

[m1abrams]

Quote:

Originally Posted by Draguljce /img/forum/go_quote.gif Hi, Perhaps an ultimate solution would be CK2III +γ2 without output coupling capacitors Thus avoiding sound coloring/degrading little bastards out of the way

How do you plan on handling the DC offset then? The y2 will produce a dc offset without the coupling caps.

 

[Draguljce]

Quote:

Originally Posted by m1abrams /img/forum/go_quote.gif How do you plan on handling the DC offset then? The y2 will produce a dc offset without the coupling caps.

AFAIK CK2III has DC servo to handle DC offset, so in theory that should work...Maybe someone has some practical experience.

 

[K3cT]

Quote:

Originally Posted by amb /img/forum/go_quote.gif K3CT, sometimes a computer's USB power voltage could be a little low, but not that low. I wonder if your computer is really out of spec? Try a different computer, and perhaps a different USB cable. Some USB cables may cause voltage drops (cable too thin or too long).

What would normal voltage reading for y1+y2 look like when powered with USB? It's a pretty new laptop and I use a Newnex USB cable so they couldn't be the problem. Could U2U be possibly defective to cause this weird issue?

Quote:

Originally Posted by pixeljedi /img/forum/go_quote.gif Are you plugging into a USB port directly from the PC or from a USB Hub connecting to the PC? I found the the Hub I use at work to be way below 5V.

Directly.

 

[MisterX]

Quote:

What would normal voltage reading for y1+y2 look like when powered with USB?

How did you ever get past the third step in the "initial check" without knowing that?

The γ1 Modular Miniature DAC


Quote:

3.If your build involves the USB board (i.e., all except the S/PDIF DAC-only (E) and full++ (F) configurations), install a temporary jumper shunt across J2U pins 1 and 2 (labeled VBUS and VCC, respectively). Then, connect the USB cable between one of your computer's USB port and the γ1's USB port. If LEDU is populated, it should illuminate. Within a short moment your operating system should detect and identify the γ1 as a "USB Audio DAC". Set your multimeter to DC V range and measure the voltage between the +5V test pad (next to J2U pin 1 "VBUS") and GND. This is your computer's USB port power voltage and should be very close to 5V. Measure the voltage between the +3.3V test pad and GND. You should read a fairly accurate 3.3V. Unplug the USB cable and remove the temporary jumper shunt.

Quote:

Could U2U be possibly defective to cause this weird issue?

Can you please follow the instructions?

(if U2U was a problem you would have never made it past the third step because the instructions also tell you "If, at any point you do not pass the check, do not proceed to the next step until the problem is first corrected")

That way we have some idea if you have a problem with the Gamma 1 USB section, the Gamma 1 S/PDIF section or the Gamma 2 board.
Follow?

 

[Wizik]

Hello all, please, what could happen if I use in y2 WM8741 and U6 (MCP100-315DI/TO) together ? In schematic is when I use WM8741 then don´t install U6, but why ? Sorry for stupid questions, i´m new in DIY

 

[amb]

U6 is a chip reset manager. WM8741/8742 don't need one, because these chips have them built-in. Only WM8740 needs it.

On the WM8741/8742 the pin that U6 is connected serves another purpose. If you connect an reset manager to it then it will have a side effect which you probably don't want.

 

[jarpatus]

Hi,

Just quick question about C19 and C25... Parts list says 1µF metallized polyester capacitors "or metallized polypropylene (MKP) in a lower capacitance". Does it actually matter what I throw in or is it "up your personal preference"? I am currently building gamma2 and just remember that I have few leftovers from CK2III, 47nF Vishay MKP1837 (can you imagine I searched for years until I found local supplier with any MKP caps, got these few weeks ago, though I had to admit that I won't hear any difference between these and MKT's I user earlier...). They would physically fit in.

Ps. If anyone does have extra SRC4192IDB or AD1896AYRS, please sell it to me, both are out of stock from Farnell and I do not want to order from Mouser since P&P would be too much.

Thanks again!

- Jari