ezDAC v.1.5 Builders Thread

[PJN]

Hi Everyone,

Well my EZDAC has burned in about eight hours so I gave my it a good listen tonight. Very nice, very real sounding, great clarity, with a very spacious sound, solid base also, it has opened up and improved since I first heard it. Kudos to Evan on a great design.

I did try the zener mod after my listening session, it didn't work no sound only a little high pitched whine. Luckily when I removed the zeners everything was fine and the DAC was singing again.

PJN

[6h5c]

Hm, that's strange, what kind of diodes did you use?

[PJN]

Hi Ray,

I used the ones specified in the 1.5 BOM

1N5314 Central Semiconductor Current Regulator Diodes

PJN

[6h5c]

Should be o.k.

Maybe the opamps don't like it? Are they AD8610? You could try a resistor instead. See here.

Ray

[PJN]

No they were out of stock so I used the substitute specified in the BOM a
LME49710.

http://cache.national.com/ds/LM/LME49710.pdf

PJN

[6h5c]

The high pitch whine indicates oscillation, maybe this type doesn't like the CRD at it's output. You can try with a passive version, a resistor, and then move up to a FET and see what it does (see link from earlier post).

Ray

[PJN]

Hi Ray,

Thanks for the info, I think that I'll try installing another PSU and separate the digital and analog stages first. I do have a couple of questions though.

U9 And U10 both feed off of the positive rail, would using a dual PSU like this one Low Current Dual Power Supply (LCDPS) - A Dual Regulated CLRC Supply make sense ? I wouldn't need a negative rail since I could leave U8 and U11 on the original bipolar supply, cut the jumpers between V1, V2, and V3, and feed U9 and U10 separately off the new PSU.

My second question is where would I hook the gnd from the new PSU to ? Just to the common ground plane like at G4 for example ?

PJN

[korben69]

Hi all

Some news after such a long time...
I've just finished soldering my EZDual, and it works fine +15.1v and -15.3v.
I'll let you know for the DAC, mostly populated, not connected yet.
I've' to check twice or more before pluging.
Do you have some tips ?
Cheers

[6h5c]

Hi Paul,

That dual PSU is perfect for the ezDAC. I would set both sections to 9V and use it to supply U8 and U9 (the digital section) through V1 and V2, and connect U10 and U11 to the ezDual (not U8 and U11 as you mentioned). This way, the analog and digital sections are separated.

Remove the two jumpers, and connect ezDual's positive output to V3. You should use G1 for the new PSU ground and G4 for the existing ezDual.

Regards,

Ray

[6h5c]

Originally Posted by korben69

Hi all

Some news after such a long time...
I've just finished soldering my EZDual, and it works fine +15.1v and -15.3v.
I'll let you know for the DAC, mostly populated, not connected yet.
I've' to check twice or more before pluging.
Do you have some tips ?
Cheers

I'd power up the ezDAC board with an adjustable bench supply if possible. I used one with current limiting as well, so nothing gets fried in case of a soldering short. And I used a magnifying glass to check the fine-pitched SMD's .

Ray