ezDAC v.1.5 Builders Thread

[merlin2069er]

What cheap walwart is needed to power the ezDual ?

Thanks,
JG

 

[ezkcdude]

I think I have a 12VAC, 1A walwart powering mine. Either 12 or 15, I'll look it up when I get home. What voltage will your regulators be set at?

 

[merlin2069er]

I think I have a 12VAC, 1A walwart powering mine. Either 12 or 15, I'll look it up when I get home. What voltage will your regulators be set at?

Hmm, not sure yet. What voltage would you suggest?

Just another quick question... Is the ezDac single sided? (are there only components on the top side?)

 

[ezkcdude]

Just another quick question... Is the ezDac single sided? (are there only components on the top side?)

The ezDAC is double-sided, but there are only a handful of components on the bottom.

 

[theAnonymous1]

Evan,

Just curious, why the low value for the I/V resistors and such a high gain in the op-amp?

 

[ezkcdude]

Evan,

Just curious, why the low value for the I/V resistors and such a high gain in the op-amp?

The theory is that it should have less noise and be more linear. At least, that's what I remember reading.

 

[theAnonymous1]

Thanks Evan,

I was just wondering because I have seen the opposite a few times (high I/V R with low gain op-amp).

 

[korben69]

Two questions before ordering parts.

1° - For T on ezDAC will PE-65612 do the job ?
Specs here : http://www.alldatasheet.com/datasheet-pdf/pdf/234300/PULSE/PE-65612.html

The PCB shows a 4 pins footprint.
All the refs quoted in the Bom's are 6 legged...
What is the orientation of the legs when ezDAC is shown on the bottom, rounded side on the outside for T ?

Do you have a Mouser ref part for this ?

2° - F1/F2 fuse on ezDual : can they be omitted ?
Those parts are hard to find and very expensive...
Bypass and have fast blow fuses behind the tranformer ?

Thanks for your advised answers ! 😉

 

[HaLo6]

F1 and F2 can be ommited, I did you just have to jumper it instead. 🙂

 

[korben69]

F1 and F2 can be ommited, I did you just have to jumper it instead. 🙂

Thanks HaLo6 !
I was just wondering about this tip for the fuses, you confirm. 😎

One question remaining, does a PE-65612 is ok as T on ezDAC ?
Specs : http://www.alldatasheet.com/datashe...E/PE-65612.html

The PCB shows 4 pins footprint, refs in Bom's have 6 legs.
What is the orientation of the legs when ezDAC is shown on the bottom, rounded side on the outside for T ?

Do you have a Mouser ref part for this ?

Last part before closing my order sheet. 😉

 

[merlin2069er]

Still looking for those parts :
- U7 : 24.576mhz Dil 3.3V RC
- T1 : 1:1 76601/2 pulse transformer or MURATA - 76601/3C

For C28/29 - 47µF Tantale - will a 16V one fit ?

I've got parts to change : 1 x SRC4192 + 1 x PCM1794

Hey, you can find the U7 at mouser.com, and the T1 should be at digikey.

 

[korben69]

Hey, you can find the U7 at mouser.com, and the T1 should be at digikey.

Thank you Merlin2069er, I've found it.
I'm solving Pulse Transformer problem too.
I've seen on the Forum that PE-65612 is ok too as T part

 

[neskor]

Couple of questions from new be :
1. What kind of transformer should I use and what voltage on secondary?
2. How to connect transformer to AC1,AC2 and AC3 if I use transformer like 2x18V with CT?
3. How to connect Dual supply PSU ( V+ , G , V- ) with EZDAC board and where and do I need U8 and U9?
4.If I don't use OPAMP do I need U10 and U11?
Thanx in advance and sorry for my English 😀

 

[merlin2069er]

Couple of questions from new be :
1. What kind of transformer should I use and what voltage on secondary?
2. How to connect transformer to AC1,AC2 and AC3 if I use transformer like 2x18V with CT?
3. How to connect Dual supply PSU ( V+ , G , V- ) with EZDAC board and where and do I need U8 and U9?
4.If I don't use OPAMP do I need U10 and U11?
Thanx in advance and sorry for my English 😀

Here's my answer to 4.
- No, if you skip the OPAMPS you don't need the regulators to power them. (and a bunch of other components)

How are you going to drive the output? You going to be going the passive route and add output transformers?

Not so sure about the your other questions, I'm going to use a walwart.

 

[neskor]

I will try first transformers than I will try jfet buffer for output or both of them 🙂

 

[merlin2069er]

I got most of my parts in today and finished up my ezDual.

An externally hosted image should be here but it was not working when we last tested it.

I haven't powered it up yet. I've got to review the docs again before I apply any power to it.

 

[merlin2069er]

Which components are mounted on the bottom?

 

[ezkcdude]

Which components are mounted on the bottom?

The ones with a ' (prime or apostrophe). For example, see C15' and C41' below:

 

[merlin2069er]

Thanks.

Would you happen to have a photo of the bottom completed?

 

[ezkcdude]

Thanks.

Would you happen to have a photo of the bottom completed?

No, I don't have one, but I'm sure someone here can take one as their building theirs. I don't really want to mess around with my setup right now, otherwise, I would take a picture of my own.