[Beefy]

Handy, because SRC4192 is just over half the price.....

 

[MrSlim]

Quote:

Originally Posted by dumbears /img/forum/go_quote.gif I'm interested in making one for myself, however, I've a lot of questions to bother you guys. Thanks in advance for your patience and help. May I ask if the SQ of audio socket in gamma-1 is the same as that of the audio socket in gamma-2? The other question is whether it's possible to have one audio socket for amp and the other for headphones/earphones? If it's possible, which is which? Moreover, if I'm to use BG NX Hi-Q 47uF/6.3V, should I add 1uF film cap parallel to it? I personally prefer Roederstein, may I use KP1830 series for both the 100pF and 220pF caps? Thanks!

It is important to understand that the audio socket on the gamma-1 is the output of the WM8501 DAC, and the audio socket(s) on the Gamma-2 are the output of the WM8740/1/2(chose your poison, with the 8741 being the best, since it takes advantage of the ASRC chip, and the fancy filtering or the 8742, which is just a cost-reduced version of the 8741 with a slightly lower S/N ratio).

All things being equal, the 8741 output should have a noticeably better sound quality (otherwise the gamma-2 would be a waste of time/money) than the 8501 output.

That said, you can use both outputs simultaneously, one for Headphones and one for an amp. The question becomes: which output should have the better converter. I could say myself that my CTH/K601's are probably much better than any amp/speaker combo I have around the house, so I might choose the 8741 output for them.. Rather than making the choice, why not build an 1 into 2 output selector so that you can use the best output for both..

 

[Beefy]

I would have thought you would drive the headphones from the y2 because of its dedicated output stage, which specifically designed to run a decent amount of current.

 

[m1abrams]

Quote:

Originally Posted by Beefy /img/forum/go_quote.gif I would have thought you would drive the headphones from the y2 because of its dedicated output stage, which specifically designed to run a decent amount of current.

Well you certainly can drive headphones from the y2 directly if you use the larger output caps. However keep in mind the output stage has a pretty limited voltage swing so that maybe an issue for some headphones.

 

[oneplustwo]

Hey folks,

My gamma 2 seems to have developed an issue. I can still get a lock on USB and optical but don't get any sound out of the gamma 2 headphone jack. I still get sound out of the gamma 1 jack though.

Thoughts?

 

[m1abrams]

Quote:

Originally Posted by oneplustwo /img/forum/go_quote.gif Hey folks, My gamma 2 seems to have developed an issue. I can still get a lock on USB and optical but don't get any sound out of the gamma 2 headphone jack. I still get sound out of the gamma 1 jack though. Thoughts?

Well I had the same symptoms on mine when I first built it and it was a bad solder joint on the SMB crystal on the y2 board.

 

[MrSlim]

Check the ASRC joints too.. I had the same problem and I re-flowed both the crystal and the ASRC pins..

 

[fault151]

very excited about the y2 upgrade, can't wait to build this.

 

[rds]

It seems that all the parts for the complete y1 and y2 builds can be ordered from Mouser and AMB Parts Shop combined.

Has anyone posted importable Mouser BOMs for the complete y1 and y2 builds? It would be really handy for many of us, and it does seem kind of inefficient for each builder to copy and paste all the part numbers over to Mouser.

 

[Billyk]

I'll put mine up, I need to through them to make sure I did not add or subtract anything. I got the y1 from MisterX but I know I have modified them.
Gamma 1
Gamma 2
Please save these for yourselves and TRIPLE check them.
Forgot to mention, I got the case from Newark, cost $11.10 $17.44 with tax and shipping

 

[grcassidy]

Thanks Billyk, you've saved my brain a whole heap of hurt.

 

[rds]

Quote:

Originally Posted by grcassidy /img/forum/go_quote.gif Thanks Billyk, you've saved my brain a whole heap of hurt.

x2

I've been ordering way too many parts lately. I just can't deal with the copy and pasting right now

 

[Nebby]

Well I saw his post after I copy and pasted all of the gamma1's parts...thanks for saving me from copy and pasting all of the gamma2 parts

 

[MisterX]

Nice try but....

A few comments about the link to the saved project at Mouser that was posted above:

You do not need a dual row 4 position pin header when U4 is populated.
You do not need U6 when either the WM8741 or WM8742 DAC chips are used.
You need more then 8 positions for the female pin headers when connecting a Gamma 1 full or Gamma 1 Plus version to the Gamma 2 and little birdie suggested you may be better not ordering them from Mouser.

The specified part number for the .1uF ceramic caps is: 80-C320C104K5R.
Why pay 10 cents extra per part for tape and reel packaged parts when you have to mess with them instead of plugging them right into the board?
The specified part number for the .01uF ceramic caps is 80-C315C103K5R.
The price is the same this time but the rest of the question remains?
(not like the $ total of those parts is a major problem but you may wish to consider revising your project)

 

[grenert]

Quote:

Originally Posted by linuxworks /img/forum/go_quote.gif I just can't find good selections of anything over than dual 'same' windings on secondaries. I often need a 5v winding for digital things, a 10 or 12v winding for things and maybe a dual rail 12 or 15 for analog things. can't find such toroids very easily. so I end up with multiple smaller ones, which I admit is less elegant.

Here's a link to some pretty versatile off-the-shelf trannies:
Mci Transformer Corporation

They'll do either 5V and dual 12V, or 5V and dual 15V. Note that these are EI, rather than toroid, but the split bobbin design means less mains noise will make it into your supply.