[maczrool]

I like the PDAC a lot, but I've never seen the battery life mentioned anywhere. What kind of battery life can one expect?

Also, when will PCBs be ready? I want to build a miniturized version, but want to start by building a full sized version first.

Thanks,

Stu

 

[aos]

Battery life depends on battery configuration. Digital section uses about 50mA while analog uses 12mA. Preferred combination is 6AA batteries for digital and 2 9V for analog. If you use rechargeables 1600mAh AA and 150mAh 9V, you'd get very approximately 32 hours life on digital and 12 hours on analog batteries. However I am changing the thing with discovery of Sharp combined optical/electrical minijack (as on minidisc?), which would bring digital consumption way down to 35mA which would give 45 hours life on digital, and also allow automatic shutdown of digital section when PDAC is used as amplifier (since voltage regulators have standby mode). Possibly this can give even automatic switching of coax / optical. However analog consumption will go up as I add voltage regulation to it. Board size will also be increased to 4 x 3".

 

[NotoriousBIG_PJ]

Will there be a wall wart version?

Biggie.

 

[ian]

And any chance for one without an analog section? (RCA outputs)

 

[aos]

Batteries are external, to be connected via DC jack(s), same ones as used by wallwarts. User can connect either battery pack(s) or wallwart(s).

Analog section is necessary - think of it as a line amp. Every DAC has it. A good line amp can drive headphones, so all that's needed is a volume control. For exclusively line-out use volume control can be removed and resistors put instead, for maximum sound quality.

 

[maczrool]

Yes, the Sharp minijack optical connectors are great, both in terms of power consumption and size, which is why I suggested using them in an earlier post on Headwize. Digikey now stocks them, so availability is great too. I will definitely be building one of your PDACs. Keep up the good work!

Stu

 

[maczrool]

Quote:

Possibly this can give even automatic switching of coax / optical.

If you decide to go with coax in your design, be sure to use a digital isolation transformer, which is considered good practice. Without it, there could be groundloop issues.

I have an ADDA converter that omits the transformer and the results are not pleasant when going between the computer and my stereo.

Stu