[francisdemarte]

Are you getting the proper voltages from the "initial check" portion of AMB's site?

Narrow down which of the boards is not working, try to see if the Y1 works first. Also try going over all the solder joints on all IC's and regulators. Most of the time just cleaning up the joints got it working for me.

 

[MisterX]

Quote:

Unfortunatly, due to a wrong part order I only have a regular (ie non illuminated) switch on the Y1 so checking for a lock is hard.

Do you know which switch you ended up with?
(if you don't know the # is it a SPDT or a DPDT? )

 

[DeadBoys]

Quote:

Originally Posted by MisterX /img/forum/go_quote.gif Do you know which switch you ended up with? (if you don't know the # is it a SPDT or a DPDT? )

Sure do its a (Mouser) 633-G13AV-RO, ON-OFF-ON SPDT.

Quote:

Originally Posted by francisdemarte /img/forum/go_quote.gif Are you getting the proper voltages from the "initial check" portion of AMB's site?

I'll check this fisrt thing in the lab tomorrow.

Quote:

Originally Posted by francisdemarte /img/forum/go_quote.gif Narrow down which of the boards is not working, try to see if the Y1 works first. Also try going over all the solder joints on all IC's and regulators. Most of the time just cleaning up the joints got it working for me.

Sorry, should have said this earlier, neither the Y1 boards mated together nor the Y1 boards mated to the Y2 produce any sound, merely static (with headphones) and nothing (plugged into M3 / amp). However they are bother recognised when plugged in over USB. This was the reasoning behind suspecting the CS8416 since I believe that the PCM2707 deals with the USB and the WM8501 is bypassed when using the Y2. Is this correct?

And thanks all for the help so far!

 

[MisterX]

Quote:

Sure do its a (Mouser) 633-G13AV-RO, ON-OFF-ON SPDT.

Did you actually install that switch in the Gamma 1 board?
If you did all it did was short circuit the LED circuit and should be removed ASAP.

 

[DeadBoys]

Quote:

Originally Posted by MisterX /img/forum/go_quote.gif Did you actually install that switch in the Gamma 1 board? If you did all it did was short circuit the LED circuit and should be removed ASAP.

Dammit, I'm such a fool

. Does that mean Q1D, Q2D are gonna be destroyed?

 

[MisterX]

Maybe give the USB input a try without the switch in there and see what you got before going down that road?

 

[DeadBoys]

Still getting nothing over USB

Quote:

Originally Posted by MisterX /img/forum/go_quote.gif Maybe give the USB input a try without the switch in there and see what you got before going down that road?

Also, the lock LED does not appear to swap when there is music going to the DAC. Does that mean no lock?

Edit: on the plus side, the LED lights which means at least one of the transistors is ok.

 

[bartvb]

I built the gamma 1 lite. It works but using my Senheiser HD 280 Pro I get very loud volume. It can only put my headphone on my head when a put the volume slider on a music player to 3% to 5%. Less than 3% is mute and more than 5% hurts my ears.

Anyone an idea what can be wrong or how to fix it? The headphone has an impedance of 64 Ohm.

 

[Beefy]

Quote:

Originally Posted by bartvb /img/forum/go_quote.gif Anyone an idea what can be wrong or how to fix it?

While the Gamma1 can be used to drive headphones directly, but it is FAR from an ideal solution. It is a DAC that is designed to drive line-level signals, meaning it works best when feeding an amplifier.

 

[amb]

It is not surprising that the volume might be very loud with sensitive, low impedance 'phones due to the strong output. If the software volume control doesn't give you enough control range, then you should either use an impedance adapter for your headphones, or better yet, a low-gain headphone amp with a proper analog volume control.

Btw, those of you who want to use a y1 to drive low impedance headphones directly should use the WM8759 DAC chip rather than WM8501. The two are identical except the former has lower output voltage.

 

[chahahc]

Hello, super newbie here. I want to build a y1 with only the mini usb input and the dc wall-wart input to mate with a y2 board. After trying to figure out the schematics, I have come to the conclusion that I would only need to solder on the components circled in these 2 diagrams linked below. Am I correct?...or is there something blatant that I'm missing?

Thanks in advance.

y1 usb interface board schematic

y1 dac board schematic

 

[MisterX]

Quote:

or is there something blatant that I'm missing?

Like say.... this same thing was covered in the gamma 2 thread a couple of months ago?

http://i23.photobucket.com/albums/b3...v100_sch-1.png

 

[landau]

Hello, I'm preparing to build gamma1&gamma2 and during the process I came across an interesting point in the CS8416 documentation, which I would like to ask a question about here.

According to this document from Cirrus Logic, one can significantly improve recovered clock jitter by setting an internal register PDUR, which is 0 by default, to 1. According to CS8416 datasheet this gets set by TX pin pulled up/down after reset.

Now, (I am a layman, please, forgive me this stupid question), does the current setup on the gamma1 board set PDUR=1?

 

[amb]

landau, no, the current revision of γ1 does not set PDUR to 1. If you want to experiment with this, it should be a simple mod. Just tack-solder a thin jumper wire from U9D pin 1 (HIPERF) to the CS8416's TX pin (you can use R6D pin 5 instead -- easier to work with). See γ1 schematic for clarification.

Since you're building this to be a γ2, and assuming you will be populating the ASRC chip, this mod would be largely superfluous because the ASRC should eliminate much of the jitter anyway.

EDIT: I should also mention that with this mod, the maximum sampling rate supported through the S/PDIF inputs are reduced from 192KHz down to 108KHz.

 

[leopoldiy]

Hi, I m french, sorry for my poor english.
Last week i have built and Gamma 1 and gamma 2 Dac and
I have some trouble with it.

In USB mode the DAC work fine, led is green and i can connect my headphone to output 1 of gamma 1 or output 2 of gamma 2.
But if i switch to optical input, it do'nt work.
if i switch to optical input and if not optical cable is plugged, led is red and no sound was avaible----> its OK

.
But if i plugg an optical cable , led still red and i can hear with high level an "FLAP FLAP FLAP" in the headphone.
I stop it for not destroy the headphone.

I have not tested the RCA spdif Input.
it'is possible that the cs8416 was out service ?
thank for your help.