[fillemon]

pretty impressive this is.

i was just looking how to make my gamma 1 even better. (i have cut the electolyte cap) was looking at putting a spare 5V line and extra caps on the chips, and now i read this,
GREAT.

i don't mind that there are no XLR or balanced outputs, you can wire them.
but to be honest, i think this dac makes it very far down the line. maybe if possible you could make a little bigger pcb where you can put extra components for dual power supply or things like that. of course you can always hack into the line. still a optional solder point for it could be nice.

SMD or not, pff, i rather prefer not, but then again if you have to solder a chip, why bother about an smd resistor, as long as you can put decent caps on it.

anyway, you know what youre doing guys, be looking forward. i think this could make the desire for a high end full blow dac away (at least for a few months

)

 

[amb]

Post #2 of this thread has been updated:

- Added schematic diagram
- Added PCB layout
- Add 3D rendering

The current version is 0.11.

 

[nattonrice]

Ohhhhhhhhh I can have the y1 dac populated as well!
The mind boggles O.O

 

[JamesL]

I'm thoroughly excited

 

[DoYouRight]

wow this is a really interesting idea. I love your designs AMB and an improved dac is really sweet. would it be very hard to make it balanced?

 

[amb]

Quote:

Originally Posted by DoYouRight /img/forum/go_quote.gif wow this is a really interesting idea. I love your designs AMB and an improved dac is really sweet. would it be very hard to make it balanced?

As already mentioned in an earlier post above, you can get balanced outputs by air-wiring from the γ2's L+, L-, R+ and R- "test points" (and of course, ground). However, this solution won't fit in the default Box B2-080 casing because there is not enough panel space for two XLR jacks, so you need to use larger casing and panels. Also, this bypasses the opamp output stage, so you don't get the low-pass filter and buffering.

 

[amb]

I would like to enlist about 10-15 of you to join MisterX and myself in the prototyping phase, which will start soon. As a member of the team, you will be amongst the first few to build a γ2. Note that you need to also build a γ1 in order to make a functioning γ2 DAC.

You must be willing to collect all the needed parts and build it promptly. You are also expected to provide feedback and comments to the team. I will set up a special email list for the the team. Of course there is also the possibility that the circuit would require modifications to work properly.

If you are interested, please PM me.

 

[1UP]

Could there be some way to send a word out clock (say, to a 1212M) so you could slave a transport to the DAC if not using USB?

 

[amb]

Quote:

Originally Posted by 1UP /img/forum/go_quote.gif Could there be some way to send a word out clock (say, to a 1212M) so you could slave a transport to the DAC if not using USB?

That isn't part of the integrated design, but if you want to hack something in yourself, you're free to do so.

 

[ruZZ.il]

Congrats on the advancement of this project! I've been waiting for your guys innovation to pop up.

I would LOVE to participate in prototyping this since it gets me all excited again

But I think I'll have to wait it out, I've got exams for the next month, getting married soon

traveling a bit... and don't have a balanced setup yet, though thats probably less the issue. I've got a few windows in-between things, so Ti please inform me on projected prototype availability and I maaaay be able to sqeeze it in. If it's in November, I'm all solder-slinging hands

. else.. I'll be eagerly waiting its completion!

 

[amb]

Hi ruZZ.il, I am hoping to get the team assembled within a week, and begin to order the boards soon after. There will be a lead-time on the boards, but after that it will be full-steam ahead. I don't want to drag the prototyping phase any longer than necessary, so maybe we'll have production boards long before November.

 

[Mr.Duck]

Might be a dumb question but is there any advantage to using the balanced outputs of the dac and converting to single ended, compared to using just the positive output of the dac and then sending it on to the buffer/filter?

I ask because if the DAC chip was to have just single ended output, then it would be nice to have some extra pads between the dac and the filter to wire up a volume control. That way you can have a USB powered DAC and headphone amp all in one. But the default config could still be made with no wires at all.

 

[MrSlim]

From post #2:

"The γ1 board's WM8501 DAC section can be fully populated and used in conjunction with the γ2 board. So the result is a compact case with two different DACs in it. You can use them both concurrently. If either of these are equipped with 470uF output capacitors (Nichicon FW or KW) then it could be used to directly drive headphones down to 32Ω impedance (You'll need to use a software volume control). On the γ2, the AD8656 is recommended for headphone drive due to its high output current capability."

Sorry MrDuck, I miss read your question.. so my answer is inappropriate..

Some one on HF has done it with an alien/mini3 clone, so it probably could be done. Whether you would want to is another story. I think most people here will want to use a dedicated headphone amp with a high quality DAC like this.

 

[amb]

Mr.Duck, if you simply used the hot (or cold) output from the DAC and discarded the opposite signal, you'll indeed have unbalanced, but you lose half the voltage swing. Also, using both the hot and cold signal and deriving an unbalanced signal from them should yield better CMRR, lower distortion and noise.

 

[hopeless]

Quote:

Originally Posted by hopeless /img/forum/go_quote.gif You can consider also the LME49721 (dual, rail to rail CMOS opamp with low distortion and the best sound I've heard from low voltage CMOS opamps), and the OPA2727 (best sound I've heard from a 4V to 12V rail to rail CMOS opamp). The OPA2365 sounds very good too, anyway. It's a pity, though, that it always makes that big sharp "pop" when powered on (and off). FIY, the OPA2376 sounds good and doesn't make it.

amb, have you contemplated my suggestions?