Battery powered DAC

Hey Chris--

The battery thing is a major drawback in the convenience department as far as I'm concerned.

Couldn't you just hook the dAck up to one of those nice dry cell batteries that serious car audio guys use for amp power? No fumes,no acid on the living room carpet, charge it once a month (or less) off the battery charger you already have in the garage. Designed as a deep cycle, so even full discharge wouldn't hurt it, stable, economical (well, $120 or so)- you could hide it in a closet and run a power lead to it.

Would there be any improvement in dynamics? If the thing sounds good with a tiny Li-ion battery pack that is rated 1.3ah, wouldn't a battery with 660 cold cranking amps basically be a super-stiff power supply, or is the little battery pack already plenty stiff?

No, I'm not kidding.

Hi Mike,

Just to clarify a little, the dAck! uses exactly what you're talking about - sealed lead acid - sorry if I was not clear in my previous post. Part of the design intent was to make something small, reasonably lightweight, inexpensive, and somewhat portable. I designed the thing with vinylphiles in mind with the knowledge that they're quite used to interactivity with their systems. Hence the small batteries - they are the largest that will fit inside the enclosure.

I could have easily spec'ed out large batteries, but like you probably know, engineering design is about compromise. It would quadruple the weight, move batteries outside the enclosure, and considerably increase the cost of the unit: extra enclosure requirements, need for durable and attractive wiring, and don't forget - overcurrent protection. This would give you a charging cyle of 24 hours to a couple days, depending on the size of the batteries.

This isn't an amp circuit or anything (it draws 100mA on average), so you're not going to get some night and day improvement by going to 42Ah. It's a bigger jump going from regulated AC-DC PSU to power cells. But yes, it does sound better (minorly) with larger cells.

Don't worry - I have some alternatives up my sleeve for you guys who just don't dig the battery thing. The system is designed modularly and new developments can be added to the existing system quite easily. What does this mean? Well you can probably figure it out from the above discussion :).

Thanks for the feedback.

-Chris

Wow, fantastic responses! I have to hear this thing!!!

i have had private correspondences w/chris - wery responsive. he told me he could provide bigger batteries w/an enlarged case for ~$100 more, that would hold a charge a lot longer. he also said he could configure it to easily hook up to a lab-grade dc power supply, of which there are a myriad awailable on ebay for pennies on the dollar. this is what i would likely do, as i cannot realistically see myself *ever* being willing to deal w/a battery power supply. i presently use a ~$1200 hewlett packard 0-20vdc, 1-4a power supply to drive my turntable's origin-live dc motor kit. i picked it up for ~$100, & it's a noticable improvement over the stock o-l supply... chris sez he cannot say for sure how a typical lab p/s would compare w/the battery supply. i think he needs to try one & see - enquiring minds wanna know! are ya listening, chris? :>)

i may have to try an ack!, to see how it compares to my self-modded art di/o. but, to be honest, i don't really have any overwhelming urge, since the di/o has aquitted itself so well against the likes of resolution audio & electrocompaniet cd players. but, the ack! certainly *looks* cool! :>)

doug s.

are you guys honestly listening to only a cd source for 6 hours non-stop every day??? my god, where do you find the time! At first the 4 to 6 hour batter life worried my, then i actually took a log of how long i listened to cds at a time.. usually between 1 and 3 hours per day (for the most part much closer to the 1 hour). Then it was either change to vinyl or do something else. I cant fathom sitting for 6 hours + only listening to cd.. some people are just way more hardcore than me! :)

cheers,
Colin