[aos]

Well, this one was the easiest yet. Digital section started working as soon as it was plugged in, now that haven't happened in a long while.

This is probably the last one. It has less parts, takes less space, less SMD parts, and is easier to build.

Trust me, soldering that DIR1703 is not a big deal AT ALL. 10 minutes tops!

For a change, this one is both DAC and a headphone amplifier. It has input jack with breakout, so as soon as you plug in something, that becomes the source and DAC is disconnected (though it is still drawing power, so if you want to do this often, put on an extra switch or just disconnect a battery.

The only drawback is impracticality of its power sources - 6AA's and 2 9V batteries (or two 7.2V Li-ion batteries). But they all still fit in the box! It's just that if AC power is required, one will have to use something like a 5-pin DIN jack and build a separate dedicated supply / charger.

However, the sound is incredible. There is plenty of gain now, volume control works wonderfully, and the sound is fantastic. Great imaging (channel separation!!), great transparency, great neutrality. Well, at least it sounds like it at the moment, I had listened to it on my speakers for only a couple of hours.

Thanks to ppl for ideas - I'm using EL2001 and AD8610 in multiloop - he was the first to try out this brand new Analog chip once I mentioned that I stumbled upon it in the Analog's newsletter.

Here are some pictures, and the full parts list with current prices for parts (comes up to $230 Canadian).

3 out of 4 prototypes:

This one:

http://members.shaw.ca/ifkovic/pdac/dac4_overview1.jpg

Closeup:

http://members.shaw.ca/ifkovic/pdac/dac4_closeup1.jpg

Parts list/prices:
http://members.shaw.ca/ifkovic/pdac/DAC PRICE v4.xls

 

[rickcr42]

by definition "frontier" means you are NEVER done

There is always a new frontier
Nice work man but you and I both know V16 is right around the corner

Rick

 

[aos]

Heh, true, but I am going to have to cut it somewhere, and that somewhere is right about now. It's time to get on with my life

. Too many non-DIY things to take care of...

Besides, with this one I have reached the goal sound-wise. It is the best source I have at home regardless of size. I will need external power source as I'm going to use it a lot as a stationary DAC. And... you DON'T want to know what percentage of my salary went to parts last year...

 

[ppl]

WOW! Great Job aos I will have to build this as i have wanted a Portable DAC for sometime. Regarding the AD-8610 I knew you would Like it. You Know Me I have to at least try any new Opamp that may be useable for Audio and from my Favorite opamp maker Analog devices no less. Yes I do thank you alot for Turning Me on to this Chip. I use this in my EL-2008 amp and this amp has never sounded Better. The EL-2008 is dificult to acomidate sonicly and is verry sensitive to what opamp is driving it. Overall the AD-744 works well for this Buffer if warm and Musical is wanted. The AD-825 it get's somewhat thin or overdampend in the Bass. The OPA-627 Way too mutch Midrange Presence and Flat non Dynamic sounding. With the AD-8610 this get's just the balance i was looking for Deep extended bass like the AD-744, Imaging and transparrancy like the AD-825 but with none of the tendacy to highlight sibelence that the 825 likes to Do. The AD-825 works best with Fast buffers like the EL-2002 and verry nice with the HA-5033/OPA633. In fact I am kind of liking the AD-825/OPA-633 combo. Great for classical but not quite Dynamic enough for rock. NOTE the OPA-633/HA-5033 dose not have Output protection so Caution is in order for any-one using it in a headphone amp must make sure no signal is present when Pulging in your Phones or Poof.Maby one of these days ill post what Opamp/Buffer combo's sound best with different musical types.